CN104701157A - Plasma etching apparatus with top disc for reducing edge etching rate - Google Patents

Abstract

A plasma etching device with a top disc for reducing the edge etching rate, comprising: a quartz top disc forming the top of a chamber of the plasma etching device; a side wall of the chamber forming a sealing surface with the quartz top disc , and further enclosed with the bottom plate of the cavity to form a vacuum chamber; the sealing ring is arranged between the quartz top disc and the side wall of the cavity, and the quartz top disc is formed on the side of the cavity side wall adjacent to the vacuum chamber The protrusion blocking device is arranged on the side of the sealing ring facing the vacuum chamber. In the present invention, a sealing ring is arranged between the quartz top disc and the side wall of the cavity, and a convex blocking device is arranged on the side of the sealing ring facing the vacuum chamber between the quartz top disc and the side wall of the cavity , which not only effectively prevents the quartz top disk adjacent to the sealing ring from being etched, maintains the sealing property, but also delays the replacement time of the quartz top disk, prolongs its service life, and reduces production costs.

Description

Plasma etch apparatus with top disk for reduced edge etch rate

technical field

The invention relates to the technical field of semiconductor manufacturing, in particular to a plasma etching device with a top disk which reduces the etching rate of the edge.

Background technique

With the reduction in the size of semiconductor devices and the increase in the size of liquid crystal displays and silicon wafers, plasma etching has gradually become a widely used etching technology in the preparation of micron-scale semiconductor devices, micro-nano manufacturing processes, and microelectronics manufacturing processes.

Plasma etching refers to the use of glow discharge to generate plasma containing charged particles such as plasma and electrons, as well as highly chemically active neutral atoms, molecules and free radicals. These active ions diffuse to the parts to be etched and are etched The etched material reacts to form volatile products and is removed, thereby completing the pattern transfer etching technology, which is an indispensable technique for realizing the high-fidelity transfer of micro-patterns in VLSI production from lithography templates to wafers. Alternative process.

However, the top disk of the conventional plasma etching equipment is connected to the side wall of the cavity through a sealing ring, and a slight gap is inevitably formed at the non-sealing ring connection. Obviously, a large amount of active free radicals such as Cl radicals and F radicals generated during plasma etching will pass through the top disk and the anti-corrosion coating while etching the semiconductor device. The top disk is etched at a slight gap in the sidewall of the chamber.

It is easy to know that since the chemical etching at the slight gap is approximately isotropic, the sealing surface of the sealing ring on the side adjacent to the sealed chamber will be gradually etched from the side. When the sealing surface is uneven due to the side etching, the sealing effect of the sealing ring is reduced, and even the vacuum cannot be maintained, resulting in the need to replace the top disc. However, the service life of the top disk is calculated based on the area below the top temperature measuring hole being etched through, which is usually 2500 radio frequency hours. In actual production, the sealing surface is often etched and replaced when there is an air leak. The service life of the disk is shortened to 1000-1500 RF hours, which not only increases the frequency of equipment maintenance, but also greatly increases the production cost.

It has become one of the technical problems to be solved urgently by those skilled in the art to seek a plasma etching device with a top disk with a simple structure, easy to use, low cost, and can effectively improve the service life of the top disk with a reduced edge etching rate. one.

Therefore, aiming at the problems existing in the prior art, the designer of this case relied on years of experience in this industry to actively research and improve, so there is a plasma etching equipment with a top disk that reduces the edge etching rate of the present invention.

Contents of the invention

The present invention is aimed at the prior art, the sealing surface of the sealing ring of the traditional plasma etching equipment adjacent to the side of the sealing chamber will be gradually etched from the side, resulting in reduced sealing effect, and even the vacuum cannot be maintained, and the sealing surface needs to be replaced. Top disc, increased production costs etc. Defects Provide a plasma etching apparatus with a top disc that reduces the edge etch rate.

To achieve the purpose of the present invention, the present invention provides a plasma etching device with a top disk that reduces the edge etching rate, the plasma etching device with the top disk that reduces the edge etching rate, comprising: The quartz top disk is made of quartz material and constitutes the top of the chamber of the plasma etching equipment; the side wall of the chamber forms a sealing surface with the quartz top disk, and is further enclosed with the bottom plate of the chamber to form a vacuum chamber a sealing ring, arranged between the quartz top disk and the side wall of the cavity, and the convex stop formed on the side wall of the cavity close to the vacuum chamber by the top of the quartz disk The device is arranged on the side of the sealing ring facing the vacuum chamber.

Optionally, a temperature measuring hole is set on the quartz top disc.

Optionally, a radio frequency system is arranged on the side of the quartz top disc different from the side wall of the cavity.

Optionally, the convex blocking device formed on the side wall of the chamber body adjacent to the vacuum chamber on the quartz top disk is a bulk blocking member, and the side wall of the convex blocking device is in contact with the vacuum chamber. The side wall of the cavity is arranged facing to each other, and a slit is formed between the side wall of the protrusion blocking device and the side wall of the cavity.

Optionally, the sidewall of the protrusion blocking device is perpendicular to the lower bottom surface of the quartz top disk facing the vacuum chamber.

Optionally, the side wall of the protrusion blocking device and the lower bottom surface of the quartz top disc facing the vacuum chamber are arranged at an oblique angle.

Optionally, a sealing ring is provided at the slit formed between the protrusion blocking device of the quartz top disc and the side wall of the cavity.

Optionally, the protrusion blocking device formed on the side wall of the chamber body adjacent to the vacuum chamber on the top of the quartz disc is an isolation sealing ring, and is arranged on the top of the quartz disc and used for The groove for accommodating the insulating sealing ring.

Optionally, the insulating sealing ring is used for replacement, and the quartz top disk is replaced when the side of the quartz top disk facing the vacuum chamber is etched to the bottom of the temperature measuring hole.

Optionally, the lifetime of the quartz top disk of the plasma etching apparatus is increased by at least 60%.

To sum up, the plasma etching equipment of the present invention has a top disk that reduces the edge etching rate by setting a sealing ring between the quartz top disk and the side wall of the cavity, and on the top of the quartz Between the disk and the side wall of the cavity, and on the side of the sealing ring facing the vacuum chamber, the protrusion blocking device is arranged at intervals, which not only effectively prevents the quartz top circle adjacent to the sealing ring from The disc is etched, maintaining the sealing properties, and delaying the replacement time of the quartz top disc, increasing its service life and reducing production costs.

Description of drawings

FIG. 1 is a schematic structural diagram of a plasma etching device with a top disk that reduces the edge etching rate according to the first embodiment of the present invention;

2 is a cross-sectional view of a plasma etching apparatus with a top disk with reduced edge etch rate according to a first embodiment of the present invention;

Fig. 3 shows the etching principle diagram of the cavity sealing surface of the plasma etching equipment of the present invention;

FIG. 4 is a schematic structural diagram of a plasma etching device with a top disk that reduces the edge etching rate according to a second embodiment of the present invention;

FIG. 5 is a schematic diagram of the etching principle of the chamber sealing surface of the plasma etching equipment of the present invention.

detailed description

In order to illustrate the technical content, structural features, achieved goals and effects of the present invention in detail, the following will be described in detail in conjunction with the embodiments and accompanying drawings.

first embodiment

Please refer to FIG. 1 . FIG. 1 is a schematic diagram showing the structure of a plasma etching device with a top disk with reduced edge etching rate according to a first embodiment of the present invention. The plasma etching equipment 1 with a top disk that reduces the edge etching rate includes: a quartz top disk 11, the quartz top disk 11 is made of quartz material, and constitutes a part of the plasma etching equipment Cavity top; cavity side wall 12, described cavity side wall 12 forms sealing surface 10 with described quartz top disk 11, and further forms vacuum chamber 14 by enclosing cavity bottom plate 13; Sealing ring 15, so The sealing ring 15 is arranged between the quartz top disc 11 and the cavity side wall 12, and the quartz top disc 11 is adjacent to the side of the vacuum chamber 14 on the cavity side wall 12 The formed protrusion blocking device 111 is disposed on a side of the sealing ring 15 facing the vacuum chamber 12 .

In the present invention, the material of the quartz top disk 11 and the cavity side wall 12 is different, and due to the influence of processing accuracy factors, the sealing surface formed by the quartz top disk 11 and the cavity side wall 12 There is a slight gap 16 at 10 places. In order to make the plasma etching equipment of the present invention have a suitable vacuum process environment, a sealing ring 15 is provided between the quartz top disk 11 and the side wall 12 of the cavity.

At the same time, in order to avoid the quartz top disc 11 adjacent to the sealing ring 15 and located on the side of the sealing ring 15 facing the vacuum chamber 14 from being etched, the quartz top disc 11 is attached to the The protrusion blocking device 111 formed on the side wall 12 of the chamber body adjacent to the vacuum chamber 14 is disposed on the side of the sealing ring 15 facing the vacuum chamber 12 .

Please refer to FIG. 2 in conjunction with FIG. 1 . FIG. 2 is a cross-sectional view of a plasma etching apparatus with a top disk with reduced edge etch rate according to a first embodiment of the present invention. As a specific embodiment, non-limiting enumeration, for example, the convex blocking device 111 formed on the side wall of the chamber 12 adjacent to the vacuum chamber 14 of the quartz top disc 11 is a bulk blocking member , and the side wall 112 of the protrusion blocking device 111 is facing to the side wall 12 of the cavity, and a narrow gap is formed between the side wall 112 of the protrusion blocking device 111 and the side wall 12 of the cavity. Seam 113.

As a person skilled in the art, it is easy to understand that the side wall 112 of the raised blocking device 111 and the side wall 12 of the cavity are arranged facing each other, and the side wall 112 of the raised blocking device 111 and the quartz top circle The lower bottom surface 114 of the disk 11 facing the vacuum chamber 12 may be vertically arranged. Alternatively, the side wall 112 of the protrusion blocking device 111 can also be arranged at an oblique angle to the lower bottom surface 114 of the quartz top disc 11 facing the vacuum chamber 12 .

Obviously, in a high-vacuum process environment, the state of the gas is molecular flow, and the gas molecules are in a state of free movement. The slit 113 is formed between the convex blocking device 111 of the quartz top disk 11 of the present invention and the side wall 12 of the cavity, which increases the molecular movement distance and reduces the probability of active free radicals entering the sealing surface 10 , reduce the edge etching rate, and prolong the service life of the quartz top disc 11 .

In order to better implement the technical solution of the present invention, more preferably, a sealing ring is provided at the slit 113 formed between the convex blocking device 111 of the quartz top disk 11 and the side wall 12 of the cavity 115, so as to further prevent active free radicals from entering the sealing surface 10 and avoid corrosion to the sealing surface 10. Optionally, the surface of the sealing ring 115 has a corrosion-resistant coating, and the corrosion-resistant coating of the sealing ring 115 includes but not limited to Al ₂ O ₃ coating, Y ₂ O ₃ coating, Y ₃ Al ₅ O ₁₂ coating, B ₄ C coating, ZrO ₂ /Y ₂ O ₃ coating, YSZ coating, etc.

In a specific implementation manner, the reactive gases used for the plasma etching process by the plasma etching equipment 1 of the present invention include but are not limited to CF ₄ /O ₂ , NF ₃ , Cl ₂ , CH ₄ /Ar and the like. Meanwhile, the active free radicals generated during the plasma etching process include but not limited to Cl radicals and F radicals.

Please refer to FIG. 3 and refer to FIG. 1 in conjunction with FIG. 3 . FIG. 3 is a schematic diagram of the etching principle of the chamber sealing surface of the plasma etching equipment of the present invention. The plasma etching equipment 1 with a top disk that reduces the edge etching rate includes: a quartz top disk 11, the quartz top disk 11 is made of quartz material, and constitutes a part of the plasma etching equipment Cavity top; cavity side wall 12, described cavity side wall 12 forms sealing surface 10 with described quartz top disk 11, and further forms vacuum chamber 14 by enclosing cavity bottom plate 13; Sealing ring 15, so The sealing ring 15 is arranged between the quartz top disc 11 and the cavity side wall 12, and the quartz top disc 11 is adjacent to the side of the vacuum chamber 14 on the cavity side wall 12 The formed protrusion blocking device 111 is disposed on a side of the sealing ring 15 facing the vacuum chamber 12 . Further, a radio frequency system 17 and a temperature measuring hole 18 are provided on the side of the quartz top disk 11 of the plasma etching equipment 1 of the present invention that is different from the side wall 12 of the cavity.

Apparently, while the active radicals are etching the semiconductor device 2, the slit 113 is formed between the protrusion blocking device 111 of the quartz top disk 11 and the cavity side wall 12 in the present invention , increasing the molecular movement distance, reducing the probability of active free radicals entering the sealing surface 10, reducing the edge etching rate, and prolonging the service life of the quartz top disc 11. According to statistical analysis of production practice, the service life of the quartz top disc 11 of the plasma etching equipment 1 is increased by at least 60%

second embodiment

The difference between the second embodiment and the first embodiment is that in order to reduce the edge etching rate, the protrusion blocking device of the quartz top disc adopts a different structure. That is, the protrusion blocking device of the quartz top disc is an isolation sealing ring and a groove arranged on the quartz top disc for accommodating the isolation sealing ring. Components in the second embodiment that are the same as those in the first embodiment are numbered with the same numbers, and will not be repeated here.

Please refer to FIG. 4 . FIG. 4 is a schematic structural diagram of a plasma etching device with a top disk with reduced edge etching rate according to a second embodiment of the present invention. The plasma etching equipment 1 with a top disk that reduces the edge etching rate includes: a quartz top disk 11, the quartz top disk 11 is made of quartz material, and constitutes a part of the plasma etching equipment Cavity top; cavity side wall 12, described cavity side wall 12 forms sealing surface 10 with described quartz top disk 11, and further forms vacuum chamber 14 by enclosing cavity bottom plate 13; Sealing ring 15, so The sealing ring 15 is arranged between the quartz top disc 11 and the cavity side wall 12, and the quartz top disc 11 is adjacent to the side of the vacuum chamber 14 on the cavity side wall 12 The formed protrusion blocking device 111 is disposed on a side of the sealing ring 15 facing the vacuum chamber 12 . Further, a radio frequency system 17 and a temperature measuring hole 18 are provided on the side of the quartz top disk 11 of the plasma etching equipment 1 of the present invention that is different from the side wall 12 of the cavity.

In the present invention, the material of the quartz top disk 11 and the cavity side wall 12 is different, and due to the influence of processing accuracy factors, the sealing surface formed by the quartz top disk 11 and the cavity side wall 12 There is a slight gap 16 at 10 places. In order to make the plasma etching equipment of the present invention have a suitable vacuum process environment, a sealing ring 15 is provided between the quartz top disk 11 and the side wall 12 of the cavity.

At the same time, in order to avoid the quartz top disc 11 adjacent to the sealing ring 15 and located on the side of the sealing ring 15 facing the vacuum chamber 14 from being etched, the quartz top disc 11 is attached to the The protrusion blocking device 111 formed on the side wall 12 of the chamber body adjacent to the vacuum chamber 14 is disposed on the side of the sealing ring 15 facing the vacuum chamber 12 .

As a specific embodiment, non-limiting enumeration, for example, the convex blocking device 111 formed on the side wall 12 of the chamber body 12 adjacent to the vacuum chamber 14 of the quartz top disk 11 is an insulating sealing ring 116 , and a groove 117 arranged on the quartz top disk 11 and used for accommodating the isolation sealing ring 116 .

Apparently, while the active radicals are etching the semiconductor device 2, the quartz top disc adjacent to the isolation sealing ring 116 and on the side of the isolation sealing ring 116 facing the vacuum chamber 14 11 will also be gradually etched by the active radicals, but the quartz top disc 11 next to the sealing ring 15 and on the side of the sealing ring 15 facing the vacuum chamber 14 is not etched. The surface of the cavity side wall 12 is provided with a corrosion-resistant coating to prevent the active free radicals from corroding it. The isolation sealing ring 116 has a corrosion-resistant coating to prevent the active free radicals from corroding it. Without limitation, the corrosion-resistant coatings of the cavity side wall 12 and the insulating sealing ring 116 include but are not limited to Al ₂ O ₃ coating, Y ₂ O ₃ coating, Y ₃ Al ₅ O ₁₂ coating , B ₄ C coating, ZrO ₂ /Y ₂ O ₃ coating, and YSZ coating.

Please refer to FIG. 5 and refer to FIG. 4 in conjunction with FIG. 5 . FIG. 5 is a schematic diagram of the etching principle of the chamber sealing surface of the plasma etching equipment of the present invention. In order to better implement the technical solution of the present invention, preferably, the insulating sealing ring 116 disposed between the quartz top disc 11 and the chamber side wall 12 can be replaced. That is, replace and use the insulating sealing ring 116 as needed, until the side of the quartz top disk 11 facing the vacuum chamber 14 is etched to the bottom of the temperature measuring hole 18 when the quartz top is replaced. Disk 11. According to statistical analysis of production practice, the service life of the quartz top disk 11 of the plasma etching equipment is increased by at least 60%.

Obviously, the plasma etching equipment 1 of the present invention has the top disk that reduces the edge etching rate by setting a sealing ring 15 between the quartz top disk 11 and the cavity side wall 12, and between the Between the quartz top disk 11 and the side wall 12 of the cavity, and on the side of the sealing ring 15 facing the vacuum chamber 14, the raised blocking device 111 is spaced apart, which not only effectively prevents the The quartz top disc 11 at the sealing ring 15 is etched to maintain the sealing property, and delay the replacement time of the quartz top disc 11, improve its service life, and reduce production costs.

To sum up, the plasma etching equipment of the present invention has a top disk that reduces the edge etching rate by setting a sealing ring between the quartz top disk and the side wall of the cavity, and on the top of the quartz Between the disk and the side wall of the cavity, and on the side of the sealing ring facing the vacuum chamber, the protrusion blocking device is arranged at intervals, which not only effectively prevents the quartz top circle adjacent to the sealing ring from The disc is etched, maintaining the sealing properties, and delaying the replacement time of the quartz top disc, increasing its service life and reducing production costs.

Those skilled in the art will appreciate that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, if any modification or variation falls within the scope of protection of the appended claims and their equivalents, the present invention is deemed to cover such modification and variation.

Claims (10)

1. A plasma etching device with a top disc that reduces the edge etching rate, characterized in that, the plasma etching device with the top disc that reduces the edge etching rate comprises: Quartz top disk, made of quartz material, and constitutes the top of the chamber of the plasma etching equipment; The side wall of the cavity forms a sealing surface with the quartz top disk, and is further enclosed with the bottom plate of the cavity to form a vacuum chamber; A sealing ring, arranged between the quartz top disk and the side wall of the cavity, and the convex blocking device formed on the side wall of the cavity side wall of the quartz top disk adjacent to the vacuum chamber It is arranged on the side of the sealing ring facing the vacuum chamber. 2 . The plasma etching device with a top disc for reducing the edge etching rate according to claim 1 , wherein a temperature measuring hole is arranged on the quartz top disc. 3 . 3. The plasma etching device with a top disk that reduces the edge etching rate as claimed in claim 1, wherein the side wall of the quartz top disk is different from the side wall of the chamber where a radio frequency system is arranged. . 4. The plasma etching apparatus having a top disk with reduced edge etch rate as claimed in claim 1, wherein said quartz top disk is adjacent to said vacuum chamber on said chamber sidewall The protruding blocking device formed on one side is a block blocking member, and the side wall of the protruding blocking device is facing the side wall of the cavity, and the side wall of the protruding blocking device and the cavity A slit is formed between the side walls of the body. 5. The plasma etch apparatus having a top disk with reduced edge etch rate as claimed in claim 4, wherein the sidewall of said raised stop means and said quartz top disk face said The lower bottom surface of the vacuum chamber is arranged vertically. 6. The plasma etching apparatus having a top disk with reduced edge etch rate as claimed in claim 4, wherein the sidewalls of said raised barriers and said quartz top disk face said The lower bottom surface of the vacuum chamber is arranged at an inclined angle. 7. The plasma etching apparatus having a top disc with reduced edge etch rate as claimed in claim 4, wherein, between the raised stopper of the quartz top disc and the sidewall of the cavity A sealing ring is provided at the formed slit. 8. The plasma etching apparatus having a top disk with reduced edge etch rate as claimed in claim 1, wherein said quartz top disk is adjacent to said vacuum chamber on said chamber sidewall The protrusion blocking device formed on one side is an isolation sealing ring, and a groove arranged on the quartz top disc for accommodating the isolation sealing ring. 9. The plasma etching apparatus with a top disc with reduced edge etch rate as claimed in claim 8, wherein said isolating seal is replaced until the side of said quartz top disc faces said vacuum The quartz top disc was replaced when the chamber side was etched to the bottom of the thermowell. 10. The plasma etch apparatus having a top disk with reduced edge etch rate as recited in claim 1, wherein the lifetime of the quartz top disk of said plasma etch apparatus is increased by at least 60%.