JP2010114379A

JP2010114379A - Infrared imaging element, and method of manufacturing the same

Info

Publication number: JP2010114379A
Application number: JP2008287975A
Authority: JP
Inventors: Koichi Ishii; 井浩一石; Hideyuki Funaki; 木英之舟; Risako Ueno; 野梨紗子上
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2008-11-10
Filing date: 2008-11-10
Publication date: 2010-05-20

Abstract

【課題】製品の歩留まりの低下を可及的に抑制する。
【解決手段】対向する第１面および第２面を有するとともに第１面から第２面に貫通する空洞部が設けられている第１絶縁層７、２４ｃと、絶縁層内に形成された第１および第２配線と、を有する配線形成部３０と、第２面側から入射された赤外線を吸収する赤外線吸収膜２４と、赤外線吸収膜と電気的に絶縁され赤外線吸収膜の温度変化を検出することにより、電気信号を生成する少なくとも１個の熱電変換素子１２と、を有し、空洞部内に設けられた赤外線検出部１０と、赤外線検出部を空洞部内に支持し、一端が第１および第２配線の他端に接続され、他端が熱電変換素子の一端に接続された第１および第２接続配線２２ａ、２２ｂと、第１および第２接続配線を覆うように形成された第１および第２絶縁膜２４ａ、２４ｂとを有する第１および第２接続配線部２０ａ、２０ｂと、を備えている。
【選択図】図２An object of the present invention is to suppress a decrease in product yield as much as possible.
SOLUTION: First insulating layers 7 and 24c each having a first surface and a second surface facing each other and having a hollow portion penetrating from the first surface to the second surface, and a first insulating layer formed in the insulating layer. A wiring forming portion 30 having first and second wirings, an infrared absorbing film 24 that absorbs infrared light incident from the second surface side, and a temperature change of the infrared absorbing film that is electrically insulated from the infrared absorbing film. And at least one thermoelectric conversion element 12 for generating an electrical signal, supporting the infrared detection unit 10 provided in the cavity, the infrared detection unit in the cavity, the first end being the first and The first and second connection wires 22a and 22b are connected to the other end of the second wire and the other end is connected to one end of the thermoelectric conversion element, and the first and second connection wires are formed to cover the first and second connection wires. And second insulating films 24a and 24b. 1 and the second connection wiring part 20a, and includes a 20b, and.
[Selection] Figure 2

Description

本発明は、赤外線撮像素子およびその製造方法に関する。 The present invention relates to an infrared imaging device and a manufacturing method thereof.

赤外線を利用した赤外線撮像素子は、昼夜に拘わらず撮像可能であると共に、可視光よりも煙や霧に対して透過性が高いという特長を有し、更に被写体の温度情報をも得られるという特長を有する。このため、防衛分野を初め監視カメラや火災検知カメラとして広い応用範囲を有する。 Infrared imaging devices that use infrared rays are capable of capturing images day and night, and are more permeable to smoke and fog than visible light, and also provide temperature information about the subject. Have For this reason, it has a wide range of applications as a surveillance camera and a fire detection camera in the defense field.

従来の主流素子である量子型赤外線固体撮像素子の最大な欠点は低温動作のための冷却機構を必要とすることであるが、近年このような冷却機構を必要としない非冷却型赤外線撮像素子が開発されている（例えば、特許文献１参照）。 The biggest drawback of the conventional quantum infrared solid-state image sensor, which is the mainstream element, is that it requires a cooling mechanism for low-temperature operation. In recent years, however, uncooled infrared image sensors that do not require such a cooling mechanism have been developed. It has been developed (see, for example, Patent Document 1).

この非冷却型赤外線撮像素子は、半導体基板と、この半導体基板上に設けられた読み出し配線部と、上記半導体基板の表面部分に形成された凹部の上方に配置され、上記読み出し配線部と電気的に接続された接続配線を有する支持構造部と、上記凹部の上方に配置され、上記支持構造部によって支持されたセル部と、を備え、上記セル部は、入射された赤外線を吸収する赤外線吸収層と、上記支持構造部と電気的に接続されると共に、上記赤外線吸収層と電気的に絶縁され、上記セル部の温度変化を検出することにより、電気信号を生成する複数の熱電変換素子と、を有している構成となっている。
特許第３７６３８２２号公報 The uncooled infrared imaging device is disposed above a semiconductor substrate, a readout wiring portion provided on the semiconductor substrate, and a recess formed in a surface portion of the semiconductor substrate, and is electrically connected to the readout wiring portion. A support structure having a connection wiring connected to the cell, and a cell part disposed above the recess and supported by the support structure part, the cell part absorbing infrared rays incident thereon. A plurality of thermoelectric conversion elements that are electrically connected to the support structure portion and electrically insulated from the infrared absorption layer and that generate an electric signal by detecting a temperature change of the cell portion; It has composition which has.
Japanese Patent No. 3763822

上記非冷却型赤外線撮像素子においては、半導体基板に凹部を形成するために、半導体基板をウェットエッチングする必要がある。このウェットエッチングによって、上記読み出し配線部の配線またはパッドメタルがエッチングされるのを防止するために、上記読み出し配線部の配線またはパッドメタルを酸化膜等で保護している。 In the uncooled infrared imaging element, it is necessary to wet-etch the semiconductor substrate in order to form a recess in the semiconductor substrate. In order to prevent the wiring or pad metal of the readout wiring portion from being etched by this wet etching, the wiring or pad metal of the readout wiring portion is protected by an oxide film or the like.

しかし、現在の技術では、上記読み出し配線部の配線またはパッドメタルを酸化膜等で保護することは十分ではなく、製品の歩留まりの低下を招いている。 However, in the current technology, it is not sufficient to protect the wiring or the pad metal of the readout wiring portion with an oxide film or the like, resulting in a decrease in product yield.

本発明は、上記事情を考慮してなされたものであって、製品の歩留まりの低下を可及的に抑制することのできる赤外線撮像素子およびその製造方法を提供することを目的とする。 The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an infrared imaging device capable of suppressing a reduction in product yield as much as possible and a method for manufacturing the same.

本発明の第１の態様による赤外線撮像素子は、対向する第１面および第２面を有するとともに前記第１面から前記第２面に貫通する空洞部が設けられている絶縁層と、前記絶縁層内に形成され外部との電気的接続のための第１および第２パッドと、前記絶縁層に前記第１面の側から形成され前記第１および第２パッドにそれぞれ通じる第１および第２開口の表面を覆うように設けられた第１および第２パッド電極と、前記絶縁層内に形成され一端が前記第１パッドに電気的に接続された第１配線と、前記絶縁層内に形成され一端が前記第２パッドに電気的に接続された第２配線と、を有する配線形成部と、前記空洞部内に設けられた赤外線検出部であって、前記第２面側から入射された赤外線を吸収する赤外線吸収膜と、前記赤外線吸収膜と電気的に絶縁され前記赤外線吸収膜の温度変化を検出することにより、電気信号を生成する少なくとも１個の熱電変換素子と、を有する赤外線検出部と、前記赤外線検出部を前記空洞部内に支持し、一端が前記第１配線の他端に接続され、他端が前記熱電変換素子の一端に接続された第１接続配線と、前記第１接続配線を覆うように形成された第１絶縁膜とを有する第１接続配線部と、前記赤外線検出部を前記空洞部内に支持し、一端が前記第２配線の他端に接続され、他端が前記熱電変換素子の他端に接続された第２接続配線と、前記第２接続配線を覆うように形成された第２絶縁膜とを有する第２接続配線部と、を備えていることを特徴とする。 An infrared imaging device according to a first aspect of the present invention includes an insulating layer having a first surface and a second surface facing each other, and a hollow portion penetrating from the first surface to the second surface, and the insulating layer. First and second pads formed in the layer for electrical connection to the outside, and first and second pads formed on the insulating layer from the first surface side and communicating with the first and second pads, respectively. First and second pad electrodes provided so as to cover the surface of the opening, a first wiring formed in the insulating layer and having one end electrically connected to the first pad, and formed in the insulating layer A wiring forming portion having one end electrically connected to the second pad, and an infrared detecting portion provided in the cavity, the infrared ray being incident from the second surface side An infrared absorbing film that absorbs, and the infrared absorbing film, An infrared detector having at least one thermoelectric conversion element that is electrically insulated and detects a temperature change of the infrared absorbing film, and that supports the infrared detector in the cavity. A first connection wiring having one end connected to the other end of the first wiring and the other end connected to one end of the thermoelectric conversion element; and a first insulating film formed to cover the first connection wiring; A first connection wiring section having a first connection wiring section, a second connection section supporting the infrared detection section in the hollow section, one end connected to the other end of the second wiring, and the other end connected to the other end of the thermoelectric conversion element. And a second connection wiring part having a connection wiring and a second insulating film formed so as to cover the second connection wiring.

また、本発明の第２の態様による赤外線撮像素子の製造方法は、絶縁膜上に素子領域を形成するとともにこの素子領域を取り囲むように絶縁体からなる素子分離領域を形成する工程と、前記素子領域に熱電変換素子を形成する工程と、一端が前記熱電変換素子の一端と電気的に接続する第１接続配線および一端が前記熱電変換素子の他端と電気的に接続する第２接続配線を前記素子分離領域上に形成する工程と、前記熱電変換素子と、前記第１および第２接続配線と、前記素子分離領域と、を覆うように、赤外線を吸収する第１絶縁層を形成する工程と、前記熱電変換素子の一端に接続する第１コンタクト、前記熱電変換素子の他端に接続する第２コンタクト、前記第１および第２接続配線の他端にそれぞれ接続する第３および第４コンタクトを前記第１絶縁層に形成する工程と、前記第１および第２コンタクトに接続する第１および第２コンタクト電極を前記第１絶縁層上に形成するとともに、第１および第２パッドと、前記第３および第４コンタクトに接続する第１および第２パッド配線電極と、前記第１パッドと前記第１パッド配線電極とを接続する第１配線と、前記第２パッドと前記第２パッド配線電極とを接続する第２配線と、を前記素子分離領域に対応する前記第１絶縁層の領域上に形成する工程と、前記第１および第２コンタクト電極、前記第１および第２パッド、前記第１および第２パッド配線電極と、前記第１配線と、前記第２配線と、を覆うように、前記第１絶縁層上に赤外線を吸収する第２絶縁層を形成する工程と、前記第２絶縁層、前記第１絶縁層、前記素子分離領域、および前記絶縁膜をパターニングして、前記第２絶縁層、前記第１絶縁層、前記素子分離領域、および前記絶縁膜を貫通する溝を形成することにより、前記熱電変換素子を有する赤外線検出部と、前記第１接続配線を有する第１接続配線部と、前記第２接続配線を形成する第２接続配線部と、前記第１および第２パッド、第１および第２配線、ならびに前記第１および第２パッド配線電極を有する配線形成部とを分離形成する工程と、前記第１および第２接続配線部の前記第２絶縁層を除去するとともに、前記第１絶縁層の一部を除去することにより、前記赤外線検出部と前記配線形成部との間に第１間隙を形成する工程と、前記赤外線検出部の前記第２絶縁層の一部分を前記第２絶縁層の上面から除去することにより、前記赤外線検出部の前記第２絶縁層の高さを前記配線形成部の前記第２絶縁層の高さよりも低くする工程と、前記第１間隙および前記溝を埋め込むように、全面に犠牲層を形成する工程と、前記配線形成部の前記第２絶縁層の上面が露出するまで前記犠牲層を削り、前記犠牲層を平坦化する工程と、前記犠牲層を覆うように、前記配線形成部の前記第２絶縁層上に、赤外線を透過する赤外線透過部を形成する工程と、前記絶縁膜の、前記熱電変換素子が形成された側と反対側の面から前記犠牲層を除去する工程と、前記絶縁膜の、前記熱電変換素子が形成された側と反対側の面から、前記絶縁膜および第１絶縁層を選択的にエッチングし、前記第１および第２パッドにそれぞれ通じる第１および第２開口を形成する工程と、前記第１および第２開口のそれぞれの表面を覆うように第１および第２パッド電極を形成する工程と、を備えていることを特徴とする。 According to a second aspect of the present invention, there is provided a method for manufacturing an infrared imaging device, comprising: forming an element region on an insulating film and forming an element isolation region made of an insulator so as to surround the element region; Forming a thermoelectric conversion element in the region; a first connection wiring having one end electrically connected to one end of the thermoelectric conversion element; and a second connection wiring having one end electrically connected to the other end of the thermoelectric conversion element. Forming on the element isolation region, forming a first insulating layer that absorbs infrared rays so as to cover the thermoelectric conversion element, the first and second connection wirings, and the element isolation region; A first contact connected to one end of the thermoelectric conversion element, a second contact connected to the other end of the thermoelectric conversion element, and third and fourth contacts connected to the other ends of the first and second connection wirings, respectively. Forming on the first insulating layer, forming first and second contact electrodes connected to the first and second contacts on the first insulating layer, and first and second pads, First and second pad wiring electrodes connected to the third and fourth contacts, a first wiring connecting the first pad and the first pad wiring electrode, the second pad and the second pad wiring electrode A second wiring for connecting the first and second contact electrodes, the first and second pads, the second wiring, and the second contact electrode, the first pad, Forming a second insulating layer that absorbs infrared radiation on the first insulating layer so as to cover the first and second pad wiring electrodes, the first wiring, and the second wiring; An insulating layer, the first insulating layer, The thermoelectric conversion element is formed by patterning the child isolation region and the insulating film to form the second insulating layer, the first insulating layer, the element isolation region, and a groove penetrating the insulating film. An infrared detection unit; a first connection wiring unit having the first connection wiring; a second connection wiring unit forming the second connection wiring; the first and second pads; the first and second wirings; A step of separately forming the wiring forming portion having the first and second pad wiring electrodes, removing the second insulating layer of the first and second connection wiring portions, and a part of the first insulating layer Removing a portion of the second insulating layer of the infrared detecting portion from the upper surface of the second insulating layer, and forming a first gap between the infrared detecting portion and the wiring forming portion. The red by Forming a sacrificial layer over the entire surface so as to fill the first gap and the groove; and a step of making the height of the second insulating layer of the outer-line detecting unit lower than the height of the second insulating layer of the wiring forming unit Cutting the sacrificial layer until the upper surface of the second insulating layer of the wiring forming portion is exposed, and planarizing the sacrificial layer, and covering the sacrificial layer with the step of the wiring forming portion. Forming an infrared transmitting portion that transmits infrared light on the second insulating layer; removing the sacrificial layer from the surface of the insulating film opposite to the side on which the thermoelectric conversion element is formed; The insulating film and the first insulating layer are selectively etched from the surface of the insulating film opposite to the side where the thermoelectric conversion element is formed, and the first and second leads to the first and second pads, respectively. Forming an opening; and the first and second openings Forming a first and second pad electrodes so as to cover the respective surfaces, characterized in that it comprises.

本発明によれば、製品の歩留まりの低下を可及的に抑制することの可能な赤外線撮像素子およびその製造方法を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the infrared image sensor which can suppress the fall of the yield of a product as much as possible, and its manufacturing method can be provided.

本発明の一実施形態による赤外線撮像素子を、図１および図２を参照して説明する。図１は、本実施形態の赤外線撮像素子の上面図であり、図２は図１に示す切断線Ａ−Ａで切断した場合の断面図である。 An infrared imaging device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a top view of the infrared imaging device of the present embodiment, and FIG. 2 is a cross-sectional view taken along the cutting line AA shown in FIG.

本実施形態の赤外線撮像素子は、赤外線検出部１０と、接続配線部２０ａ、２０ｂと、配線形成部部３０と、赤外線透過部４０と、を備えている。本実施形態においては、これらの赤外線検出部１０、接続配線部２０ａ、２０ｂ、および配線形成部３０は、それぞれ絶縁膜４上に形成されている。そして、赤外線検出部１０は、配線形成部３０によって取り囲まれており、赤外線検出部１０と配線形成部３０と間には、間隙４２ａが設けられている。すなわち、赤外線検出部１０は、配線形成部３０とは間隙４２ａを介して隔離されている。しかし、赤外線検出部１０と配線形成部３０とは、間隙４２ａに設けられた接続配線部２０を通して接続される構成となっている。 The infrared imaging element of this embodiment includes an infrared detection unit 10, connection wiring units 20 a and 20 b, a wiring formation unit 30, and an infrared transmission unit 40. In the present embodiment, the infrared detection unit 10, the connection wiring units 20a and 20b, and the wiring formation unit 30 are each formed on the insulating film 4. The infrared detecting unit 10 is surrounded by the wiring forming unit 30, and a gap 42 a is provided between the infrared detecting unit 10 and the wiring forming unit 30. That is, the infrared detecting unit 10 is isolated from the wiring forming unit 30 via the gap 42a. However, the infrared detecting unit 10 and the wiring forming unit 30 are connected through the connection wiring unit 20 provided in the gap 42a.

赤外線検出部１０はセル部とも呼ばれ、複数（図１では、４個）の熱電変換素子１２を有している。本実施形態においては、これらの熱電変換素子１２は、ダイオードとなっているが、抵抗体であってもよい。これらの複数の熱電変換素子すなわち、ダイオード１２は、直列に接続された構成となっている。各ダイオード１２は、絶縁膜４上に設けられた半導体層（例えば、Ｓｉ層）に形成される。そして、各ダイオード１２は、上記半導体層内に設けられたｎ型不純物層１２ａと、ｐ型不純物層１２ｂとを備え、これらの不純物層１２ａ、１２ｂからなるｐｎ接合を有している。ｐ型不純物層１２ｂは、上記半導体層内に設けられたｐ型の高濃度不純物層であるｐ^＋型不純物層１３に形成されている。ｎ型不純物層１２ａは、ｐ型不純物層１２ｂに形成されている。これらのダイオード１２は、素子分離絶縁膜７によって素子分離されるとともに、絶縁材からなり赤外線を吸収する赤外線吸収膜（例えば、ＳｉＮ膜またはＳｉＯ_２膜）２４によって覆われている。また、ｎ型不純物層１２ａは赤外線吸収膜２４内に設けられた配線電極１５にコンタクト１４を介して電気的に接続され、ｐ^＋型不純物層１３は赤外線吸収膜２４内に設けられた配線電極１７にコンタクト１６を介して電気的に接続されている。これらの配線電極１５、１７を適切に電気的に接続することにより、複数のダイオード１２が直列に接続される。 The infrared detection unit 10 is also called a cell unit, and includes a plurality (four in FIG. 1) of thermoelectric conversion elements 12. In the present embodiment, these thermoelectric conversion elements 12 are diodes, but may be resistors. The plurality of thermoelectric conversion elements, that is, the diodes 12 are connected in series. Each diode 12 is formed in a semiconductor layer (for example, Si layer) provided on the insulating film 4. Each diode 12 includes an n-type impurity layer 12a and a p-type impurity layer 12b provided in the semiconductor layer, and has a pn junction including these impurity layers 12a and 12b. The p-type impurity layer 12b is formed in the p ⁺ -type impurity layer 13 which is a p-type high concentration impurity layer provided in the semiconductor layer. The n-type impurity layer 12a is formed in the p-type impurity layer 12b. These diodes 12 are element-isolated by the element isolation insulating film 7 and are covered with an infrared absorption film (for example, SiN film or SiO ₂ film) 24 made of an insulating material and absorbing infrared rays. The n-type impurity layer 12 a is electrically connected to the wiring electrode 15 provided in the infrared absorption film 24 via the contact 14, and the p ⁺ -type impurity layer 13 is a wiring electrode provided in the infrared absorption film 24. 17 is electrically connected through a contact 16. A plurality of diodes 12 are connected in series by appropriately electrically connecting these wiring electrodes 15 and 17.

接続配線部２０ａは絶縁膜４上に設けられた素子分離絶縁膜７と、絶縁膜２４ａと、この絶縁膜２４ａ内に設けられた接続配線２２ａとを備え、接続配線部２０ｂは絶縁膜４上に設けられた素子分離絶縁膜７と、絶縁膜２４ｂと、この絶縁膜２４ｂ内に設けられた接続配線２２ｂとを備えている。接続配線部２０ａの接続配線２２ａは直列に接続された複数のダイオード１２からなる直列回路の一端に接続され、接続配線部２０ｂの接続配線２２ｂは直列に接続された複数のダイオード１２からなる直列回路の他端に接続されている。 The connection wiring portion 20a includes an element isolation insulating film 7 provided on the insulating film 4, an insulating film 24a, and a connection wiring 22a provided in the insulating film 24a. The connection wiring portion 20b is provided on the insulating film 4. The device isolation insulating film 7 provided on the insulating film 24, the insulating film 24b, and the connection wiring 22b provided in the insulating film 24b are provided. The connection wiring 22a of the connection wiring part 20a is connected to one end of a series circuit composed of a plurality of diodes 12 connected in series, and the connection wiring 22b of the connection wiring part 20b is a series circuit composed of a plurality of diodes 12 connected in series. Is connected to the other end.

配線形成部３０は、絶縁膜４上に形成された素子分離絶縁膜７と、絶縁膜２４ｃと、配線電極３２ａ、３２ｂと、パッド３４ａ、３４ｂと、パッド電極３８ａ、３８ｂとを備えている。配線電極３２ａ、３２ｂ、パッド３４ａ、３４ｂ、およびパッド電極３８ａ、３８ｂは、絶縁膜２４ｃ内に設けられている。配線電極３２ａは、接続配線２２ａと電気的に接続される。すなわち、配線電極３２ａは接続配線２２ａを介して複数のダイオード１２からなる直列回路の一端に接続される。また、配線電極３２ｂは、接続配線２２ｂと電気的に接続される。すなわち、配線電極３２ｂは接続配線２２ｂを介して複数のダイオード１２からなる直列回路の他端に接続される。また、配線電極３２ａは絶縁膜２４ｃ内に設けられた図示しない配線を介してパッド３４ａに電気的に接続され、配線電極３２ｂは絶縁膜２４ｃ内に設けられた図示しない配線を介してパッド３４ｂに電気的に接続される。また、絶縁膜２４ｃには絶縁膜４側から設けられた開口３６ａ、３６ｂが形成されている。そして、開口３６ａはパッド３４ａに通じ、パッド３６ｂはパッド３４ｂに通じる。すなわち、パッド３４ａは絶縁膜４側から設けられた開口３６ａの底面となり、パッド３４ｂは絶縁膜４側から設けられた開口３６ｂの底面となるように構成されている。また、パッド電極３８ａはパッド３４ａの側面および底面、すなわち表面を覆うように形成され、パッド電極３８ｂはパッド３４ｂの側面および底面、すなわち表面を覆うように形成されている。そして、配線形成部３０の、パッド電極３８ａ、３８ｂが設けられた側とは反対側の面には、赤外線検出部１０を覆うように、赤外線の透過率の高い部材からなる赤外線透過部４０が設けられている。この赤外線透過部４０と赤外線検出部１０との間には、間隙４２ｂが設けられている。なお、絶縁膜２４ａ、２４ｂ、２４ｃは赤外線吸収膜２４と同じ材料から構成されていてもよい。 The wiring forming unit 30 includes an element isolation insulating film 7 formed on the insulating film 4, an insulating film 24c, wiring electrodes 32a and 32b, pads 34a and 34b, and pad electrodes 38a and 38b. The wiring electrodes 32a and 32b, the pads 34a and 34b, and the pad electrodes 38a and 38b are provided in the insulating film 24c. The wiring electrode 32a is electrically connected to the connection wiring 22a. That is, the wiring electrode 32a is connected to one end of a series circuit including the plurality of diodes 12 through the connection wiring 22a. The wiring electrode 32b is electrically connected to the connection wiring 22b. That is, the wiring electrode 32b is connected to the other end of the series circuit composed of the plurality of diodes 12 through the connection wiring 22b. The wiring electrode 32a is electrically connected to the pad 34a via a wiring (not shown) provided in the insulating film 24c, and the wiring electrode 32b is connected to the pad 34b via a wiring (not shown) provided in the insulating film 24c. Electrically connected. In addition, openings 36a and 36b provided from the insulating film 4 side are formed in the insulating film 24c. The opening 36a communicates with the pad 34a, and the pad 36b communicates with the pad 34b. That is, the pad 34a is configured to be the bottom surface of the opening 36a provided from the insulating film 4 side, and the pad 34b is configured to be the bottom surface of the opening 36b provided from the insulating film 4 side. The pad electrode 38a is formed so as to cover the side surface and the bottom surface, that is, the surface of the pad 34a, and the pad electrode 38b is formed so as to cover the side surface and the bottom surface, that is, the surface of the pad 34b. And on the surface opposite to the side where the pad electrodes 38a, 38b are provided of the wiring forming portion 30, there is an infrared transmitting portion 40 made of a member having a high infrared transmittance so as to cover the infrared detecting portion 10. Is provided. A gap 42 b is provided between the infrared transmission unit 40 and the infrared detection unit 10. The insulating films 24a, 24b, and 24c may be made of the same material as the infrared absorption film 24.

このように構成された本実施形態の赤外線撮像素子においては、赤外線検出部１０は、配線形成部３０内に形成された間隙４２ａ、４２ｂを有する空洞部４２内に設けられてかつ接続配線部２０ａ、２０ｂによって支持された構成となっている。したがって、赤外線透過部４０を介して、赤外線検出部１０に入射した赤外線は、赤外線吸収膜２４によって吸収され、この赤外線吸収膜２４内に生じた熱エネルギーにより、赤外線吸収膜２４の温度が上昇する。この温度変化が熱電変換素子（ダイオード）１２によって電気信号に変換されて赤外線検出部１０の出力（電圧）となる。この出力は、接続配線２２ａ、２２ｂ等を介してパッド電極３８ａ、３８ｂから取り出される。 In the infrared imaging element of the present embodiment configured as described above, the infrared detecting unit 10 is provided in the cavity 42 having the gaps 42a and 42b formed in the wiring forming unit 30, and the connecting wiring unit 20a. , 20b. Therefore, the infrared light incident on the infrared detection unit 10 through the infrared transmission unit 40 is absorbed by the infrared absorption film 24, and the temperature of the infrared absorption film 24 rises due to the thermal energy generated in the infrared absorption film 24. . This temperature change is converted into an electrical signal by the thermoelectric conversion element (diode) 12 and becomes an output (voltage) of the infrared detection unit 10. This output is taken out from the pad electrodes 38a and 38b via the connection wirings 22a and 22b.

また、本実施形態においては、赤外線検出部１０からの熱の逃げ道は、接続配線部２０ａ、２０ｂのみとなる。したがって、赤外線検出部１０の熱隔離性は、接続配線部２０ａ、２０ｂの熱コンダクタンスによって決定され、接続配線部２０ａ、２０ｂの長さが長く構成されればされるほど、また細く形成すればするほど断熱性は向上する。 Moreover, in this embodiment, the escape route of the heat from the infrared detection part 10 is only the connection wiring parts 20a and 20b. Therefore, the thermal isolation of the infrared detection unit 10 is determined by the thermal conductance of the connection wiring parts 20a and 20b, and the longer the connection wiring parts 20a and 20b are configured, the thinner the thinness is. The better the heat insulation.

次に、本実施形態の赤外線撮像素子の製造方法を図３（ａ）乃至図４（ｃ）を参照して説明する。 Next, a method for manufacturing the infrared imaging element of the present embodiment will be described with reference to FIGS. 3 (a) to 4 (c).

まず、半導体基板として単結晶シリコンからなる支持基板２上に、埋め込みシリコン酸化膜４、単結晶シリコン層（ＳＯＩ層）６が順次積層された、いわゆるＳＯＩ基板１を準備する（図３（ａ））。続いて、素子分離としてＳＴＩ（Shallow Trench Isolation）と同様の工程を行う。すなわち、フォトリソグラフィー等の技術を用いて素子分離領域を画定し、素子分離領域のＳＯＩ層６を、例えばＲＩＥ（Reactive Ion Etching）等の技術によりエッチング除去し、その後、素子分離シリコン酸化膜をＣＶＤ（Chemical Vapor Deposition）等の技術により埋め込み、ＣＭＰ（Chemical Mechanical Polishing）等の技術で平坦化することにより、素子分離絶縁膜７を形成する（図３（ｂ））。素子分離絶縁膜７によって分離された素子領域６にダイオード１２が形成される。 First, a so-called SOI substrate 1 is prepared in which a buried silicon oxide film 4 and a single crystal silicon layer (SOI layer) 6 are sequentially laminated on a support substrate 2 made of single crystal silicon as a semiconductor substrate (FIG. 3A). ). Subsequently, the same process as STI (Shallow Trench Isolation) is performed as element isolation. That is, an element isolation region is defined using a technique such as photolithography, and the SOI layer 6 in the element isolation area is etched away by a technique such as RIE (Reactive Ion Etching), and then an element isolation silicon oxide film is formed by CVD. An element isolation insulating film 7 is formed by embedding by a technique such as (Chemical Vapor Deposition) and flattening by a technique such as CMP (Chemical Mechanical Polishing) (FIG. 3B). A diode 12 is formed in the element region 6 isolated by the element isolation insulating film 7.

次に、図３（ｃ）に示すように、周知の技術を用いて、素子分離領域７上に接続配線部となる絶縁膜２４ａ、２４ｂを形成し、この絶縁膜２４ａ、２４ｂ上に接続配線２２ａ、２２ｂをそれぞれ形成する。その後、図３（ｄ）に示すように、フォトリソグラフィー技術とイオン注入等のドーピング技術とを用いて、素子領域６に、ダイオード１２のｐｎ接合を形成するためのｎ型不純物層１２ａおよびｐ型不純物層１２ｂを形成する。続いて、ｐ型不純物層１２ｂの外側を覆うように、ｐ^＋型不純物層１３を形成する（図３（ｄ））。 Next, as shown in FIG. 3C, insulating films 24a and 24b to be connection wiring portions are formed on the element isolation region 7 using a known technique, and connection wiring is formed on the insulation films 24a and 24b. 22a and 22b are formed, respectively. Thereafter, as shown in FIG. 3D, an n-type impurity layer 12a and a p-type for forming a pn junction of the diode 12 in the element region 6 using a photolithography technique and a doping technique such as ion implantation. Impurity layer 12b is formed. Subsequently, a p ⁺ type impurity layer 13 is formed so as to cover the outside of the p type impurity layer 12b (FIG. 3D).

次に、図４に示すように、赤外線を吸収する絶縁膜（赤外線吸収膜）２４を全面に形成する。その後、ｎ型不純物層１２ａおよびｐ^＋型不純物層１３にそれぞれ接続するコンタクト１４、１６を絶縁膜２４に形成する（図４）。 Next, as shown in FIG. 4, an insulating film (infrared absorbing film) 24 that absorbs infrared rays is formed on the entire surface. Thereafter, contacts 14 and 16 connected to the n-type impurity layer 12a and the p ⁺ -type impurity layer 13 are formed in the insulating film 24 (FIG. 4).

続いて、図５に示すように、金属膜を絶縁膜２４上に堆積し、リソグラフィー技術を用いて、この金属膜をパターニングすることにより、コンタクト１４に接続する配線電極１５と、コンタクト１６に接続する配線電極１７と、複数のダイオード１２を直列に接続するように配線電極１５と配線電極１７との間を接続する配線（図示せず）と、配線形成部に設けられる配線電極３２ａ、３２ｂおよびパッド３４ａ、３４ｂと、配線電極３２ａとパッド３４ａとの間を接続する配線（図示せず）と、配線電極３２ｂとパッド３４ｂとの間を接続する配線（図示せず）と、を絶縁膜２４上に形成する。このとき、配線電極３２ａは、絶縁膜２４に設けられた図示しないコンタクトを介して接続配線２２ａを介して接続されるので、配線電極３２ａは、直列に接続された複数のダイオード１２からなる直列回路の一端と、接続配線２２ａを介して接続される。また、配線電極３２ｂは、絶縁膜２４に設けられた図示しないコンタクトを介して接続配線２２ｂを介して接続されるので、配線電極３２ｂは、直列に接続された複数のダイオード１２からなる直列回路の他端と、接続配線２２ｂを介して接続される。 Subsequently, as shown in FIG. 5, a metal film is deposited on the insulating film 24, and this metal film is patterned using a lithography technique, thereby connecting the wiring electrode 15 connected to the contact 14 and the contact 16. Wiring electrode 17 to be connected, wiring (not shown) connecting wiring electrode 15 and wiring electrode 17 so as to connect a plurality of diodes 12 in series, wiring electrodes 32a and 32b provided in the wiring forming portion, and The insulating film 24 includes pads 34a and 34b, wiring (not shown) connecting the wiring electrode 32a and the pad 34a, and wiring (not shown) connecting the wiring electrode 32b and the pad 34b. Form on top. At this time, since the wiring electrode 32a is connected via the connection wiring 22a via a contact (not shown) provided on the insulating film 24, the wiring electrode 32a is a series circuit composed of a plurality of diodes 12 connected in series. Are connected to one end of each via a connection wiring 22a. In addition, since the wiring electrode 32b is connected via the connection wiring 22b via a contact (not shown) provided on the insulating film 24, the wiring electrode 32b is a series circuit composed of a plurality of diodes 12 connected in series. The other end is connected via the connection wiring 22b.

次に、図６に示すように、これらの配線電極１５、１７、３２ａ、３２ｂ、およびパッド３４ａ、３４ｂならびに配線を覆うように、赤外線を吸収する絶縁膜２４を形成する。続いて、図７に示すように、ＲＩＥ ( R e a c t i v e I o n E t c h i n g) 等の異方性エッチングを用いて絶縁膜２４をパターニングすることにより絶縁膜２４内に支持基板２に達する溝５０を形成し、赤外線検出部１０および接続配線部２０ａ、２０ｂを配線形成部３０から分離する。この分離工程により、絶縁膜２４は、赤外線検出部１０では赤外線吸収膜２４となり、接続配線部２０ａ、２０ｂではそれぞれ、絶縁膜２４ａ、２４ｂとなり、配線形成部３０では絶縁膜２４ｃとなる。 Next, as shown in FIG. 6, an insulating film 24 that absorbs infrared rays is formed so as to cover these wiring electrodes 15, 17, 32 a, 32 b, pads 34 a, 34 b and wiring. Subsequently, as shown in FIG. 7, a groove 50 reaching the support substrate 2 is formed in the insulating film 24 by patterning the insulating film 24 using anisotropic etching such as RIE (Reactive I on Etching). Then, the infrared detection unit 10 and the connection wiring units 20 a and 20 b are separated from the wiring formation unit 30. By this separation step, the insulating film 24 becomes the infrared absorbing film 24 in the infrared detecting unit 10, becomes the insulating films 24 a and 24 b in the connection wiring parts 20 a and 20 b, and becomes the insulating film 24 c in the wiring forming part 30.

次に、図８に示すように、接続配線部２０ａ、２０ｂ上の絶縁膜２４ａ、２４ｂの一部をその上面から選択的にエッチングし、赤外線検出部１０と配線形成部３０との間に間隙４２ａを形成する。 Next, as shown in FIG. 8, a part of the insulating films 24 a and 24 b on the connection wiring portions 20 a and 20 b is selectively etched from the upper surface, and a gap is formed between the infrared detection unit 10 and the wiring formation unit 30. 42a is formed.

次に、図９に示すように、赤外線検出部１０の赤外線吸収膜２４の一部をその上面から選択的にエッチングし、赤外線吸収膜２４の高さを配線形成部３０の絶縁膜２４ｃの高さよりも低くする。 Next, as shown in FIG. 9, a part of the infrared absorption film 24 of the infrared detection unit 10 is selectively etched from its upper surface, and the height of the infrared absorption film 24 is set to the height of the insulating film 24 c of the wiring formation unit 30. Lower than that.

次に、図１０に示すように、間隙４２ａを埋め込むように、犠牲層５２を全面に形成する。犠牲層５２としては、アモルファスシリコンまたはポリイミドを用いることができる。 Next, as shown in FIG. 10, a sacrificial layer 52 is formed on the entire surface so as to fill the gap 42a. As the sacrificial layer 52, amorphous silicon or polyimide can be used.

続いて、図１１に示すように、ＣＭＰ(Chemical Mechanical Polishing)を用いて、絶縁膜２４ｃの上面が露出するまで犠牲層５２を削り、犠牲層５２を平坦化する。 Subsequently, as shown in FIG. 11, the sacrificial layer 52 is removed by CMP (Chemical Mechanical Polishing) until the upper surface of the insulating film 24c is exposed, and the sacrificial layer 52 is planarized.

次に、図１２に示すように、絶縁膜２４ｃおよび犠牲層５２の上面に、赤外線の透過率が高い部材を接着し、赤外線透過部４０を形成する。赤外線透過部４０の材料として、ＳｉまたはＧｅが使用可能である。赤外線透過部の接着は、直接接合する技術や接着剤による貼付け方法を用いることが可能である。直接接合においては、例えば次のようなプロセスによって行う。まず、ダイオードが形成されている基板の接合面と、赤外線透過部材の接合面の洗浄及び表面処理を行って、親水化処理を施す。次に、両接着面同士を重ね合わせて接合する。接着剤を使用する方法は、まず、赤外線透過部材もしくは基板のいずれか一方に接着剤シートを積層し、赤外線検出部に相当する部分以外の部分、すなわち配線形成部３０に接着剤が残るようにパターン露光する。次に、現像によりパターンに従って不要な接着剤を除去し、必要な前処理を行った後に両者を貼り合せて接着する。 Next, as shown in FIG. 12, a member having a high infrared transmittance is bonded to the upper surfaces of the insulating film 24 c and the sacrificial layer 52, thereby forming the infrared transmitting portion 40. Si or Ge can be used as the material of the infrared transmitting portion 40. The adhesion of the infrared transmission part can be performed by a direct joining technique or an adhesive sticking method. In the direct bonding, for example, the following process is performed. First, the bonding surface of the substrate on which the diode is formed and the bonding surface of the infrared transmitting member are washed and surface-treated to perform a hydrophilic treatment. Next, both adhesive surfaces are overlapped and joined. First, the adhesive sheet is laminated on either the infrared transmitting member or the substrate so that the adhesive remains in the portion other than the portion corresponding to the infrared detecting portion, that is, the wiring forming portion 30. Pattern exposure. Next, unnecessary adhesive is removed according to the pattern by development, and after necessary pretreatment, both are bonded and bonded.

次に、裏面の処理プロセスに入る。まず、図１３に示すように、グラインダー等を用いて支持基板２を研削し、除去する。その後、図１４に示すように、配線形成部３０の絶縁膜７、２４ｃ内に、絶縁膜４側からパッド３４ａ、３４ｂにそれぞれ到達する開口３６ａ、３６ｂを形成する。続いて、図１５に示すように、開口３６ａ、３６ｂの側面および底面、すなわち表面を覆うように、例えばスパッタ法もしくは蒸着法を用いてパッド電極３８ａ、３８ｂを形成する。次に、図１６に示すように、裏面から犠牲層５２をウェットエッチングにより除去することにより、赤外線検出部１０と配線形成部３０との間に間隙４２ａを形成するとともに、赤外線検出器１０と赤外線透過部４０との間に間隙４２ｂを形成する。これにより、赤外線検出部１０が、配線形成部３０内に形成された間隙４２ａ、４２ｂを有する空洞部４２内に設けられてかつ接続配線部２０ａ、２０ｂによって支持された構成の赤外線撮像素子となる。 Next, the back surface processing process is started. First, as shown in FIG. 13, the support substrate 2 is ground and removed using a grinder or the like. Thereafter, as shown in FIG. 14, openings 36 a and 36 b reaching the pads 34 a and 34 b from the insulating film 4 side are formed in the insulating films 7 and 24 c of the wiring forming portion 30. Subsequently, as shown in FIG. 15, pad electrodes 38 a and 38 b are formed by using, for example, a sputtering method or a vapor deposition method so as to cover the side surfaces and bottom surfaces of the openings 36 a and 36 b, that is, the surface. Next, as shown in FIG. 16, by removing the sacrificial layer 52 from the back surface by wet etching, a gap 42a is formed between the infrared detection unit 10 and the wiring formation unit 30, and the infrared detector 10 and the infrared ray are formed. A gap 42b is formed between the transmitting portion 40 and the transmitting portion 40. As a result, the infrared detection unit 10 is an infrared imaging device having a configuration in which the infrared detection unit 10 is provided in the cavity 42 having the gaps 42a and 42b formed in the wiring forming unit 30 and supported by the connection wiring units 20a and 20b. .

このように形成された赤外線撮像素子は、図１７に示すように、パッド電極３８ａ、３８ｂがハンダボール７０等を介して、基板８０に形成された外部のパッケージ配線と接続される。そして、赤外線撮像素子を、基板８０上にハンダボール等を介して複数個マトリクス状に配置すれば、赤外線撮像装置を得ることができる。 In the infrared imaging element formed in this way, as shown in FIG. 17, pad electrodes 38a and 38b are connected to external package wiring formed on a substrate 80 via solder balls 70 and the like. An infrared imaging device can be obtained by arranging a plurality of infrared imaging elements in a matrix on the substrate 80 via solder balls or the like.

以上説明したように、本実施形態の赤外線撮像素子は、空洞部４２を形成する際に、パッド３４ａ、３４ｂおよび配線等は、パッド電極３８ａ、３８ｂおよび絶縁膜２４、２４ａ、２４ｂ、２４ｃによって覆われており、露出していないので、パッド３４ａ、３４ｂおよび配線等がエッチングされるのを防止することができ、製品の歩留まりの低下を可及的に抑制することができる。 As described above, in the infrared imaging device of this embodiment, when the cavity 42 is formed, the pads 34a and 34b and the wiring are covered with the pad electrodes 38a and 38b and the insulating films 24, 24a, 24b, and 24c. Since it is not exposed, it is possible to prevent the pads 34a and 34b, the wiring, and the like from being etched, and to reduce the yield of the product as much as possible.

一実施形態による赤外線撮像素子の平面図。The top view of the infrared image sensor by one Embodiment. 一実施形態による赤外線撮像素子の断面図。1 is a cross-sectional view of an infrared imaging device according to an embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment. 一実施形態による赤外線撮像素子の製造工程を示す断面図。Sectional drawing which shows the manufacturing process of the infrared imaging element by one Embodiment.

Explanation of symbols

２支持基板
４埋め込み絶縁膜
６ＳＯＩ層（単結晶シリコン層）
７素子分離絶縁膜
１０赤外線検出部
１２熱電変換素子（ダイオード）
１２ａｎ型不純物層
１２ｂｐ型不純物層
１３ｐ^＋型不純物層
１４コンタクト
１５配線電極
１６コンタクト
１７配線電極
２０ａ接続配線部
２０ｂ接続配線部
２２ａ接続配線
２２ｂ接続配線
２４光吸収膜
２４ａ絶縁膜
２４ｂ絶縁膜
２４ｃ絶縁膜
３０配線形成部
３２ａ配線電極
３２ｂ配線電極
３４ａパッド
３４ｂパッド
３６ａ開口
３６ｂ開口
３８ａパッド電極
３８ｂパッド電極
４０赤外線透過部
４２空洞部
４２ａ間隙
４２ｂ間隙 2 Support substrate 4 Embedded insulating film 6 SOI layer (single crystal silicon layer)
7 Element isolation insulating film 10 Infrared detector 12 Thermoelectric conversion element (diode)
12a n-type impurity layer 12b p-type impurity layer 13 p ⁺ -type impurity layer 14 contact 15 wiring electrode 16 contact 17 wiring electrode 20a connecting wiring portion 20b connecting wiring portion 22a connecting wiring 22b connecting wiring 24 light absorption film 24a insulating film 24b insulating film 24c Insulating film 30 Wiring forming part 32a Wiring electrode 32b Wiring electrode 34a Pad 34b Pad 36a Opening 36b Opening 38a Pad electrode 38b Pad electrode 40 Infrared transmitting part 42 Cavity part 42a Gap 42b Gap

Claims

An insulating layer having a first surface and a second surface facing each other and having a hollow portion penetrating from the first surface to the second surface, and an electrical connection formed between the insulating layer and the outside First and second pads, and first and second pads formed to cover the surfaces of the first and second openings formed on the insulating layer from the first surface side and respectively leading to the first and second pads. A second pad electrode, a first wiring formed in the insulating layer and having one end electrically connected to the first pad, and one end formed in the insulating layer and electrically connected to the second pad A wiring forming portion having a second wiring;
An infrared detecting unit provided in the cavity, the infrared absorbing film absorbing infrared incident from the second surface side, and the temperature change of the infrared absorbing film electrically insulated from the infrared absorbing film An infrared detecting unit having at least one thermoelectric conversion element that generates an electrical signal by detecting;
The infrared detection unit is supported in the cavity, a first connection wiring having one end connected to the other end of the first wiring and the other end connected to one end of the thermoelectric conversion element, and the first connection wiring A first connection wiring portion having a first insulating film formed to cover;
A second connection wiring that supports the infrared detection unit in the cavity, has one end connected to the other end of the second wiring and the other end connected to the other end of the thermoelectric conversion element; and the second connection wiring A second connection wiring portion having a second insulating film formed so as to cover
An infrared imaging device comprising:

The infrared imaging element according to claim 1, wherein there are a plurality of thermoelectric conversion elements, and these thermoelectric conversion elements are connected in series.

The infrared imaging element according to claim 1, wherein the thermoelectric conversion element is a pn junction diode.

The infrared imaging element according to claim 1, wherein the thermoelectric conversion element is a resistor.

An infrared transmitting part provided on the second surface side of the wiring forming part is further provided so as to cover the infrared detecting part, and a gap is provided between the infrared detecting part and the infrared transmitting part. The infrared imaging device according to any one of claims 1 to 4.

Forming an element region on the insulating film and forming an element isolation region made of an insulator so as to surround the element region;
Forming a thermoelectric conversion element in the element region;
Forming a first connection wiring having one end electrically connected to one end of the thermoelectric conversion element and a second connection wiring having one end electrically connected to the other end of the thermoelectric conversion element on the element isolation region;
Forming a first insulating layer that absorbs infrared rays so as to cover the thermoelectric conversion element, the first and second connection wirings, and the element isolation region;
A first contact connected to one end of the thermoelectric conversion element; a second contact connected to the other end of the thermoelectric conversion element; and third and fourth contacts connected to the other ends of the first and second connection wirings, respectively. Forming the first insulating layer;
First and second contact electrodes connected to the first and second contacts are formed on the first insulating layer, and first and second pads and first and second contacts connected to the third and fourth contacts are formed. A second pad wiring electrode; a first wiring that connects the first pad and the first pad wiring electrode; and a second wiring that connects the second pad and the second pad wiring electrode. Forming on the region of the first insulating layer corresponding to the isolation region;
The first insulating layer so as to cover the first and second contact electrodes, the first and second pads, the first and second pad wiring electrodes, the first wiring, and the second wiring. Forming a second insulating layer that absorbs infrared rays on the surface;
The second insulating layer, the first insulating layer, the element isolation region, and the insulating film are patterned to penetrate the second insulating layer, the first insulating layer, the element isolation region, and the insulating film. By forming a groove, an infrared detection unit having the thermoelectric conversion element, a first connection wiring unit having the first connection wiring, a second connection wiring unit forming the second connection wiring, and the first Separating the second pad, the first and second wirings, and the wiring forming part having the first and second pad wiring electrodes;
By removing the second insulating layer of the first and second connection wiring portions and removing a part of the first insulating layer, a first gap is formed between the infrared detecting portion and the wiring forming portion. Forming a step;
By removing a part of the second insulating layer of the infrared detecting unit from the upper surface of the second insulating layer, the height of the second insulating layer of the infrared detecting unit is set to the second insulating layer of the wiring forming unit. The step of lower than the height of,
Forming a sacrificial layer over the entire surface so as to fill the first gap and the groove;
Scraping the sacrificial layer until an upper surface of the second insulating layer of the wiring forming portion is exposed, and planarizing the sacrificial layer;
Forming an infrared transmitting portion that transmits infrared light on the second insulating layer of the wiring forming portion so as to cover the sacrificial layer;
Removing the sacrificial layer from the surface of the insulating film opposite to the side where the thermoelectric conversion element is formed;
The insulating film and the first insulating layer are selectively etched from the surface of the insulating film opposite to the side where the thermoelectric conversion element is formed, and the first and second pads respectively leading to the first and second pads are etched. Forming two openings;
Forming first and second pad electrodes so as to cover respective surfaces of the first and second openings;
A method for manufacturing an infrared detecting element, comprising:

The method for manufacturing an infrared imaging element according to claim 6, wherein the thermoelectric conversion elements are plural, and the thermoelectric conversion elements are connected in series.

8. The method of manufacturing an infrared imaging element according to claim 6, wherein the thermoelectric conversion element is a pn junction diode.