阅读说明：本技术 一种提高清洗效率的等离子腔室 (Plasma chamber capable of improving cleaning efficiency ) 是由 林轩宇 柳雪 柴智 王琳琳 于 2020-06-13 设计创作，主要内容包括：本发明公开了一种提高清洗效率的等离子腔室,包括喷淋板、抽气环、加热盘以及陶瓷套；其中,所述喷淋板与抽气环的间隙尺寸小于1mm。该结构中喷淋板与抽气环采用新的配合方式,从而应用该结构达到了降低PECVD腔内的清洗时间、气体用量及颗粒度,提高产能,节约成本,降低硬件损伤的目的。(The invention discloses a plasma chamber for improving cleaning efficiency, which comprises a spray plate, an air extraction ring, a heating plate and a ceramic sleeve, wherein the spray plate is arranged on the spray plate; wherein, the clearance size of shower plate and gas extraction ring is less than 1 mm. The novel matching mode is adopted for the spray plate and the air exhaust ring in the structure, so that the structure is applied to achieve the purposes of reducing the cleaning time, the gas consumption and the granularity in a PECVD (plasma enhanced chemical vapor deposition) cavity, improving the productivity, saving the cost and reducing the hardware damage.)

1. A plasma chamber for improving the cleaning efficiency is characterized by comprising a spray plate, an air exhaust ring, a heating plate and a ceramic sleeve; the spray plate is located the cavity upper cover plate, and the heating plate sets up with the spray plate relatively, and the ceramic cover is overlapped on the heating plate, wherein the ring of bleeding is located the spray plate below, with the contact of spray plate, there is the clearance in the contact surface, the clearance size is less than 1 mm.

2. The plasma chamber of claim 1, wherein the shower plate has a stepped configuration and the side of the protruding showerhead is angled.

3. The plasma chamber of claim 2, wherein the diameter of the plane of the array of shower plate holes to the diameter of the lower surface of the shower plate is greater than: 0.496:1-0.714:1.

4. The plasma chamber of claim 2, wherein the diameter of the plane of the array of shower plate holes to the diameter of the lower surface of the shower plate is greater than: 0.725:1-0.991:1.

5. The plasma chamber of claim 2 wherein the end of the pumping ring adjacent the shower plate is chamfered.

6. The improved cleaning efficiency plasma chamber as recited in claim 5 wherein said shower plate is angled to coincide with the angle of the pumping annulus.

7. The plasma chamber of claim 1 wherein the lower surface of the shower plate is free of steps and has a planar configuration.

8. The plasma chamber of claim 7 wherein the diameter of the plane of the array of shower plate holes to the diameter of the lower surface of the shower plate is: 0.495:1-0.712:1.

9. The plasma chamber of claim 7 wherein the diameter of the plane of the array of shower plate holes to the diameter of the lower surface of the shower plate is: 0.723:1-0.988:1.

10. The improved cleaning efficiency plasma chamber as recited in claim 7 wherein said pumping ring ends in a right angle configuration.

11. The plasma chamber of claim 7 wherein the pumping ring lower surface is in vertical contact with the pumping ring end.

12. The plasma chamber of claim 1, wherein an RPS line is connected below the heater plate.

Technical Field

The invention belongs to the technical field of plasma enhanced chemical vapor deposition hardware, and relates to a plasma chamber for improving cleaning efficiency.

Background

In the preparation of the PECVD (plasma enhanced chemical vapor deposition) film in the prior art, a deposition chamber usually uses a shower plate as an upper polar plate, a heating plate for carrying a silicon wafer and as a lower polar plate, and radio frequency is applied in the process, so that plasma (plasma) forming a reaction source participates in the PECVD reaction to generate the film. Generally, the reaction gas flows into the chamber from above the shower plate, and the reaction excess gas and the reaction by-products are pumped out of the chamber through the pumping ring. As shown in FIG. 1, the relative positions of the shower plate 101 and the pumping ring 102 are shown in FIG. 3, which is a cross-section taken along the axis A of FIG. 1;

at present, there is certain clearance (dotted line frame region in fig. 2) in the middle of spray plate 101 and the ring 102 of bleeding, plasma can get into deposit film in the gap, after the technology, carry out the abluent in-process of cavity, spray plate and heating plate and bleed the very easy clearance of the surperficial film of ring, nevertheless spray plate and bleed the film in the gap between the ring, increase the degree of difficulty for wasing, often the difficult sanitization in the gap, cause 101 spray plate lateral wall to wash the difficulty, the scavenging period is longer, the cleaning efficiency is very low, the productivity is low, the purge gas quantity is many, and is with high costs. Meanwhile, the spraying plate is made of aluminum, the air exhaust ring is made of ceramic, and plasma enters a gap between the spraying plate and the air exhaust ring in the technical process, so that abnormal point discharge is easily generated on the edge of the side wall of the spraying plate 101, and the damage of the spraying plate is caused.

Disclosure of Invention

The invention solves the problem that in the process of generating the PECVD film, a connecting part of a used spray plate and an air extracting ring has a gap, plasma can enter the gap to deposit the film, and the difficulty is increased for cleaning a cavity after the process is finished.

In order to solve the problems, the invention provides a plasma chamber for improving the cleaning efficiency, which comprises a spraying plate, an air exhaust ring, a heating plate and a ceramic sleeve; the spray plate is located the cavity upper cover plate, and the heating plate sets up with the spray plate relatively, sits in the cavity, and ceramic cover is on the heating plate, wherein bleed the ring and be located the spray plate below, with the spray plate contact, the contact surface has the clearance, the clearance size is less than 1 mm.

Preferably, the spraying plate is of a stepped structure, and an angle is arranged on the side face of the protruding spray head.

Preferably, the diameter ratio of the plane where the spray plate array holes are located to the lower surface of the spray plate is: 0.496:1-0.714:1.

Preferably, the diameter ratio of the plane where the spray plate array holes are located to the lower surface of the spray plate is: 0.725:1-0.991:1.

Preferably, the end part of the air extracting ring close to the side surface of the spraying plate is of a chamfer structure.

Preferably, the shower plate is at an angle to the extraction ring.

Further, the contact gap between the air pumping ring and the spraying plate is 0;

preferably, the lower surface of the spray plate has no step and is of a planar structure.

Preferably, the diameter ratio of the plane where the spray plate array holes are located to the lower surface of the spray plate is: 0.495:1-0.712:1.

Preferably, the diameter ratio of the plane where the spray plate array holes are located to the lower surface of the spray plate is: 0.723:1-0.988:1.

Optionally, the end of the gas extraction ring is of a right-angle structure.

Optionally, the lower surface of the pumping ring is vertically contacted with the end part of the pumping ring.

Optionally, an RPS pipe is connected to the lower part of the heating plate.

The invention has the beneficial effects that:

in the embodiment of the invention, the plasma chamber adopts a new matching structure of the spray head and the gas extraction ring, the gap between the spray head and the gas extraction ring is not more than 1mm, and plasma can not enter the plasma chamber in the process, i.e. a film can not be deposited, so that after the process is finished, the residual film in the chamber is reduced, the cleaning time of the chamber is greatly reduced, and the productivity of the whole machine is obviously improved; meanwhile, the probability of damage to the spray plate is reduced, hardware damage caused by abnormal discharge of the tip is reduced, and cost is saved. Meanwhile, the RPS is connected to the lower part of the heating plate in the cavity in a matching manner, plasma directly enters the lower part of the heating plate when clean gas is cleaned, the concentration of clean gas plasma is improved, the cleaning efficiency is further improved, and the productivity is increased.

Drawings

In order to facilitate understanding for those skilled in the art, the present invention will be further described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the relative positions of a spray plate and an air extraction ring in the prior art;

FIG. 2 is a cross-sectional view of the spray plate and pumping ring in relative position;

FIG. 3 is a cross-sectional view of the shower plate and pumping ring arrangement of embodiment 1 taken along the axis A of FIG. 1;

FIG. 4 is a cross-sectional view of the shower plate and pumping ring arrangement of embodiment 2 taken along the axis A of FIG. 1;

fig. 5 is a schematic structural view of a chamber according to embodiment 3 of the present invention.

Detailed Description

The invention will be further explained with reference to specific embodiments, without limiting the invention.

As shown in fig. 1 and 2, a spray plate in a PECVD cavity is positioned on an upper cover plate of the cavity and serves as an upper polar plate of a PECVD reaction, a heating plate is opposite to the spray plate and is seated in the cavity to serve as a lower polar plate of the PECVD reaction, and a ceramic sleeve is directly sleeved on the heating plate; the pumping ring is positioned in the cavity, has a diameter larger than that of the heating plate, has a certain gap with the heating plate, and is positioned on the side surface of the heating plate in the process to pump away redundant reaction gas and reaction byproducts.

In the conventional preparation of PECVD films, a spray plate is usually used as an upper polar plate in a deposition chamber, a heating plate is used for bearing a silicon wafer and is used as a lower polar plate, and radio frequency is applied in the process, so that plasma of a reaction source is formed to participate in PECVD reaction to generate the films. Generally, reaction gas flows into a chamber from the upper part of a spray plate, reaction redundant gas and reaction byproducts are pumped out of the chamber through an air pumping ring, a joint part of the existing spray plate and the air pumping ring has a gap, plasma can enter the gap to deposit a film, and after the process is finished, the film in the gap is difficult to clean and is often the most difficult to clean in the gap in the process of chamber clean; therefore, in the embodiment, the cleaning efficiency of the PECVD reaction chamber is improved by changing the matching structure of the spray plate and the gas extraction ring;

example 1

As shown in fig. 3, the deposition reaction chamber has a shower plate 101 and an exhaust ring 102, and the fitting structure of the shower plate and the exhaust ring is adjusted so that the gap size between the shower plate and the exhaust ring is not greater than 1 mm.

The method specifically comprises the following steps:

the spraying plate is of a stepped structure, an angle is arranged on the side face of the protruding spray head, and a chamfer structure is arranged at the end part of the air exhaust ring close to the side face of the spraying plate.

Further improved, the angle of the spraying plate is consistent with that of the air extracting ring.

By adopting the matching structure, the uniformity of the deposited film can be ensured, and the indoor hardware replacement and problem troubleshooting of the switch cavity can be realized at any time during the daily use and maintenance of the equipment; the error between the spraying plate and the chamfer angle of the air extracting ring needs to be controlled within +/-2 degrees.

The diameter ratio of the plane where the spray plate array holes are located to the lower surface of the spray plate is as follows: 0.496:1-0.714: 1;

the diameter ratio of the plane where the spray plate array holes are located to the lower surface of the spray plate is as follows: 0.725:1-0.991:1.

Practice proves that the diameter ratio is more beneficial to the distribution of air flow in the process and the uniformity of the film appearance on the surface of the wafer.

Example 2

In order to further adjust the matching structure of the spray plate and the air extraction ring, the gap between the spray plate 101 and the air extraction ring 102 is completely eliminated, i.e. the spray plate is processed into a flat plate structure, and at the moment, the spray plate and the air extraction ring are in vertical positions, and no gap exists between the side walls. The method can ensure the high-efficiency generation of the film deposition and improve the cleaning efficiency of the chamber.

The spraying plate is adjusted to be of a plane structure, and the end part of the air pumping ring is of a right-angle structure.

Optionally, the lower surface of the pumping ring is vertically contacted with the end part of the pumping ring.

The diameter ratio of the plane where the spray plate array holes are located to the lower surface of the spray plate is as follows: 0.495:1-0.712:1.

Further, the diameter ratio of the plane where the array holes of the spraying plate are located to the lower surface of the spraying plate is as follows: 0.723:1-0.988:1.

Under the condition, the diameter ratio is more beneficial to the air flow distribution in the process and the uniformity of the film appearance on the surface of the wafer.

The matching structure can ensure that no gap exists between the spray header and the air extraction ring, and the plasma can not enter the process, namely, the film can not be deposited, so that after the process is finished, the residual film in the cavity is reduced, the cavity cleaning time is reduced, and the productivity of the whole machine is improved;

the film deposited in the cavity is reduced, so the using amount of cleaning gas is reduced, and the cost is reduced;

in conclusion, the spraying plate is made of aluminum, the air exhaust ring is made of ceramic, and plasma cannot enter the gap when the gap is not more than 1mm, so that abnormal discharge cannot occur at the side wall edge of the spraying plate, and the probability of damage to the spraying plate is reduced. Hardware damage caused by abnormal discharge of the tip is reduced, and cost is saved;

the original gap between the two hardware spraying plates 101 and the air extraction ring 102 is adjusted to be not more than 1mm, and a gap plasma with the size of 1mm cannot enter, so that a film is not deposited, the cleaning difficulty is reduced, and after the method is adopted, the cleaning time is saved by 20-50%, the yield of a machine table is improved by 9-20%, the gas consumption is reduced by 20-50%, and the cost is greatly saved.

Example 3

As shown in FIG. 5, to further increase the cleaning speed and continue to optimize the efficiency of the bottom of the heater plate, the PECVD is performed with Ar, NF₃And O₂The clean gas flows through the RPS to be ionized to form plasma, and then enters the cavity after passing through the spray plate to perform clean reaction. At the moment, the films above the heating plate and on the front surface of the spraying plate enter intensively due to the fact that the plasma is high in concentration, the position is easy to clean, when the films deposited at the bottom of the heating plate are cleaned, the plasma can only enter through gaps of the heating plate and the air exhaust ring, so that the plasma concentration is limited, the cleaning efficiency is low, the RPS pipeline is connected to the lower portion of the heating plate in the cavity, clean gas directly enters the lower portion of the heating plate when being cleaned, the concentration of clean gas plasma is improved, the cleaning efficiency is further improved, and the productivity is increased.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.