CN219873401U

CN219873401U - Plasma processing equipment

Info

Publication number: CN219873401U
Application number: CN202321032284.3U
Authority: CN
Inventors: 刘自强; 丁科允
Original assignee: Jiangsu Tianxin Micro Semiconductor Equipment Co ltd
Current assignee: Jiangsu Tianxin Micro Semiconductor Equipment Co ltd
Priority date: 2023-04-28
Filing date: 2023-04-28
Publication date: 2023-10-20
Anticipated expiration: 2033-04-28

Abstract

The present utility model provides a plasma processing apparatus comprising: the processing cavity is used for removing the oxide on the surface of the wafer; one end of the plasma generating device is connected with the processing cavity and is used for converting the process gas introduced into the processing cavity into a plasma state; the output end of the gas mixing cavity is connected with the other end of the plasma generating device and is used for mixing the process gas before the process gas is introduced into the processing cavity; the input end of the gas mixing cavity is connected with a fluorine-containing gas input pipeline and a nitrogen-containing hydrogen gas input pipeline. The plasma processing equipment provided by the utility model is provided with the gas mixing cavity, so that the process gas can be mixed more uniformly, and a better process effect is brought to the cleaning process of the oxide layer on the surface of the wafer.

Description

Plasma processing equipment

Technical Field

The present utility model relates to the field of semiconductor devices, and in particular to the field of plasma processing devices.

Background

In semiconductor processes, the wafer surface is cleaned of oxide prior to epitaxial deposition, and therefore a wafer precleaning apparatus, typically a plasma processing apparatus, is required to subsequently perform further epitaxial processes on the wafer, such wafer surface oxide removal processes being wafer precleaning processes. In the pre-cleaning process, process gas is introduced into a processing cavity of plasma processing equipment, and mixed and sprayed to the surface of a wafer to react with oxides on the surface of the wafer, so that the effect of removing the oxides is achieved.

However, the following problems still exist in the process of removing the oxide on the surface of the wafer in the prior art:

in the prior art, the process gas enters the processing cavity of the plasma processing equipment in two ways, the two ways of gas are mixed only through the gas spray heads arranged in the processing cavity, a good mixing state still cannot be achieved before the process gas reaches the surface of the wafer, and the distribution of the two ways of gas on the whole surface of the wafer is uneven, so that oxide residues exist in partial areas of the surface of the wafer after the surface of the wafer is cleaned, a good cleaning effect cannot be obtained, and the quality of a subsequent epitaxial process can be affected.

Disclosure of Invention

The utility model aims to provide plasma processing equipment which can mix process gases more uniformly, bring better effect to the cleaning process of an oxide layer on the surface of a wafer and improve the process quality of the surface of the wafer.

In order to achieve the above object, the present utility model is realized by the following technical scheme:

there is provided a plasma processing apparatus including:

the processing cavity is used for removing the oxide on the surface of the wafer;

one end of the plasma generating device is connected with the processing cavity and is used for converting the process gas introduced into the processing cavity into a plasma state;

the output end of the gas mixing cavity is connected with the other end of the plasma generating device and is used for mixing the process gas before the process gas is introduced into the processing cavity;

the input end of the gas mixing cavity is connected with a fluorine-containing gas input pipeline and a nitrogen-containing hydrogen gas input pipeline.

Further, the gas mixing chamber includes a heating device disposed at an outer circumference of the gas mixing chamber for heating the process gas entering the gas mixing chamber.

Further, the heating device is an electric heating belt.

Further, the electric heating belt comprises at least one group of electric heating wires, and the electric heating belt is arranged around the chamber wall where the non-input end and the non-output end of the gas mixing chamber are located.

Further, the gas mixing chamber further includes:

the pumping pipeline is connected to the chamber wall where the output end of the gas mixing chamber is located and is used for extracting process gas from the gas mixing chamber so as to adjust the gas pressure of the gas mixing chamber;

and the conveying pipeline is connected with the output end of the gas mixing cavity and the other end of the plasma generating device and is used for introducing the process gas mixed in the gas mixing cavity into the plasma generating device.

Further, the processing cavity comprises a base, a processing cavity body, a gas spray head and a vacuum pump, wherein the base is arranged in the processing cavity body and is used for bearing a wafer; the gas spray head is arranged at the upper part of the processing cavity and is used for spraying the process gas introduced into the processing cavity to the surface of the wafer placed on the base; the vacuum pump is arranged on one side of the cavity of the processing cavity and used for adjusting the air pressure in the cavity of the processing cavity.

Further, the pumping pipeline is connected with the vacuum pump.

Further, at least one pressure control device is arranged on the pumping pipeline and used for controlling the air pressure of the air mixing cavity.

Further, the gas mixing chamber further includes at least one gas dispersing plate for dispersing the process gas inputted into the gas mixing chamber from the input line into the entire mixing chamber space.

Further, the dispersion surface of the gas dispersion plate is perpendicular to the gas input direction of the process gas from the inside of the mixing chamber.

Further, the number of the gas dispersing plates is two, the gas dispersing plate close to the direction of the input end of the gas mixing cavity is a first gas dispersing plate, the gas dispersing plate close to the direction of the output end of the gas mixing cavity is a second gas dispersing plate, the dispersing holes of the second gas dispersing plate are smaller than those of the first gas dispersing plate, and the dispersing holes of the second gas dispersing plate are distributed more densely than those of the first gas dispersing plate.

Compared with the prior art, the utility model has the following advantages:

the utility model provides plasma processing equipment which comprises a gas mixing cavity, so that the process gas can be fully mixed in the gas mixing cavity before entering the processing cavity of the plasma processing equipment, and the problem of poor cleaning effect of oxide on the surface of a wafer caused by uneven mixing of the process gas in the processing cavity in the prior art is solved.

Furthermore, the gas mixing cavity provided by the utility model can be internally provided with the gas dispersing plate, and the gas dispersing plate can further improve the mixing effect of the process gas in the gas mixing cavity and improve the processing uniformity of wafers in plasma processing equipment.

Drawings

For a clearer description of the technical solutions of the present utility model, the drawings that are needed in the description will be briefly introduced below, it being obvious that the drawings in the following description are one embodiment of the present utility model, and that, without inventive effort, other drawings can be obtained by those skilled in the art from these drawings:

fig. 1 is a schematic view of a structure of a plasma processing apparatus according to the present utility model.

Detailed Description

The following provides a further detailed description of the proposed solution of the utility model with reference to the accompanying drawings and detailed description. The advantages and features of the present utility model will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for the purpose of facilitating and clearly aiding in the description of embodiments of the utility model. For a better understanding of the utility model with objects, features and advantages, refer to the drawings. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that any modifications, changes in the proportions, or adjustments of the sizes of structures, proportions, or otherwise, used in the practice of the utility model, are included in the spirit and scope of the utility model which is otherwise, without departing from the spirit or essential characteristics thereof.

Fig. 1 shows a schematic structure of a plasma processing apparatus according to the present utility model, which is used for cleaning oxide on a wafer surface in the semiconductor field. The plasma processing equipment comprises a processing cavity 100, a plasma generating device 401 and a gas mixing cavity 200, wherein the processing cavity 100 is used for carrying out removal process treatment on oxide on the surface of a wafer; one end of the plasma generating device 401 is connected with the processing chamber 100, and is used for converting the process gas introduced into the processing chamber into a plasma state; the output end of the gas mixing chamber 200 is connected with the other end of the plasma generating device, and is used for mixing the process gas before the process gas is introduced into the processing chamber; the input end of the gas mixing chamber is connected with a fluorine-containing gas input pipeline 203 and a nitrogen-containing hydrogen gas input pipeline 204, the fluorine-containing gas input pipeline 203 is connected with a fluorine-containing gas source 302, and the nitrogen-containing hydrogen gas input pipeline 204 is connected with a nitrogen-containing hydrogen gas source 301.

The process chamber 100 comprises a liner 114, a process chamber body 105, a lifting device 109, a base 104, a gas shower head 121 and a vacuum pump, wherein the process chamber body 105 comprises a side wall, and the inner surface of the side wall is in a general ring shape; the bushing 114 is generally annular and is disposed on an inner surface of a sidewall of the processing chamber 105, and specifically, the inner surface of the sidewall of the processing chamber 105 has a step, and the bushing 114 can be placed on the step; a gas spray head 121 is arranged above the top of the processing cavity 105, the gas spray head 121 is arranged in the process gas inlet 102, the lifting device 109 is arranged at the bottom of the processing cavity 105, the base 104 is arranged at the top of the lifting device 109, the base 104 is used for placing a wafer to be cleaned, the base 104 is arranged in the lining 114, the height of the base 104 is changed through the lifting device 109, the base 104 is lowered, the wafer is supported by the pins 110, and the base 104 is separated from the wafer so that the wafer can be taken by a manipulator; during operation, the processing cavity 105 is vacuumized, the plasma generated by the plasma generating device 401 is mixed with the input process gas through the gas spray header 121 to generate reaction gas, the reaction gas enters the processing cavity 105 and reacts with the oxide on the surface of the wafer, so that the oxide layer on the surface of the wafer is removed, the reaction gas after cleaning is converged through the vent hole on the liner 114, passes through the first channel 113, enters the second channel 112, and is discharged to the outside of the cavity through the tail gas channel 106 and the tail gas interface 107 arranged on the side wall of the processing cavity 105 under the action of the vacuum pump.

As shown in fig. 1, in the plasma processing apparatus provided by the present utility model, the output end of the mixing chamber 200 is connected to the other end of the plasma generating device 401, the mixing chamber 200 includes a mixing chamber 201, a fluorine-containing gas input pipeline 203, a nitrogen-containing hydrogen gas input pipeline 204, a pumping pipeline 208, and a conveying pipeline 206, so that after the fluorine-containing gas source 302 and the nitrogen-containing hydrogen gas source 301 generate the fluorine-containing gas and the nitrogen-containing hydrogen gas, the fluorine-containing gas and the nitrogen-containing hydrogen gas enter the gas mixing chamber 201 through the respective conveying pipelines 203 and 204, are fully mixed in the gas mixing chamber, and then are conveyed to the plasma generating device through the conveying pipeline 206, so that the process gas becomes a plasma state, and finally, are sprayed onto the surface of the wafer through the gas spray head 121 disposed in the process gas inlet 102 of the processing chamber to react with the oxide layer on the surface of the wafer. During the gas mixing process, the pumping line 208 adjusts the gas pressure conditions of the gas mixing chamber by adjusting a pressure control device 212 disposed on the pumping line. Compared with the prior art, the plasma processing equipment provided by the utility model provides the gas mixing cavity 200 for fully mixing the process gas in advance, and solves the problem that the process gas directly enters the processing cavity 105 and is unevenly mixed at the process gas inlet 102.

The mixing chamber 200 is further provided with a heating device 202, and the heating device 202 is arranged at the periphery of the mixing chamber 200 and is used for heating the process gas while the process gas enters the mixing chamber for mixing.

Optionally, the heating device 202 is an electric heating belt, and covers the outer surface of the gas mixing cavity 201; preferably, the electric heating belt comprises a plurality of groups of electric heating wires, and the electric heating belt surrounds the outer surface of the chamber wall where the non-input end and the non-output end of the mixing chamber cavity 201 are located, so that the process gas in the whole mixing chamber cavity 201 is uniformly heated.

Optionally, the pumping pipeline 208 is connected to the vacuum pump, that is, the pumping pipeline 208 is connected to the exhaust channel 106 disposed on the sidewall of the processing chamber 105, which share an exhaust port 107 and a vacuum pump, and the air pressure in the gas mixing chamber 201 is adjusted by the pressure control device 212 disposed on the pumping pipeline 208 according to the pumping rate of the vacuum pump.

Optionally, the gas mixing cavity 201 further includes at least one gas dispersing plate, where a dispersing surface of the gas dispersing plate is perpendicular to an input direction of the process gas entering the gas mixing cavity 201 from the input pipelines 203 and 204, and the gas dispersing plate is configured to enable gas mixing to be more uniform and enhance a gas mixing effect.

Preferably, the number of the gas dispersing plates is two, namely a first gas dispersing plate 218 and a second gas dispersing plate 216, the first gas dispersing plate 218 and the second gas dispersing plate 216 are arranged in parallel, the first gas dispersing plate 218 is arranged in the direction of the input end of the gas mixing chamber 200, and the second gas dispersing plate 216 is arranged in the direction of the output end of the gas mixing chamber 200. The dispersion holes of the second gas dispersion plate 216 are smaller than the dispersion holes of the first gas dispersion plate 218, and the dispersion holes of the second gas dispersion plate 216 are more densely distributed than the dispersion holes of the first gas dispersion plate 218. After the process gas enters the gas mixing cavity 201 through the input pipelines 203 and 204, the process gas reaches the second gas dispersing plate 216 after being mixed by the first gas dispersing plate 218, and the effect of secondary mixing can be achieved due to smaller and denser dispersing holes, so that the arrangement of the two layers of gas dispersing plates 216 and 218 can help the gas mixing in the gas mixing cavity, and the uniform mixing effect of the gas is enhanced.

Optionally, a pressure difference exists between the gas mixing chamber 201 and the processing chamber 105, so that the process gas after being uniformly mixed may enter the plasma generating device 401 through the conveying pipeline 206 under the action of the pressure difference, and the conveying pipeline is provided with the gas flow control device 210 to adjust the conveying rate. More preferably, the pressure difference is 15Torr.

Alternatively, the process gas described in the present utility model includes a fluorine-containing gas and a nitrogen-hydrogen-containing gas.

Optionally, the material of the gas mixing cavity comprises any one of aluminum or stainless steel.

The plasma processing equipment provided by the utility model comprises the gas mixing cavity, and can mix the process gas outside the cavity of the processing cavity, so that the effect of uniform gas is achieved, the problem of poor cleaning effect of the surface of the wafer due to uneven gas mixing is avoided, and the cleaning process quality of the wafer is effectively improved.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

While the present utility model has been described in detail through the foregoing description of the preferred embodiment, it should be understood that the foregoing description is not to be considered as limiting the utility model. Many modifications and substitutions of the present utility model will become apparent to those of ordinary skill in the art upon reading the foregoing. Accordingly, the scope of the utility model should be limited only by the attached claims.

Claims

1. A plasma processing apparatus, comprising:

2. The plasma processing apparatus according to claim 1, wherein the gas mixing chamber includes a heating device provided at an outer periphery of the gas mixing chamber for heating the process gas entering the gas mixing chamber.

3. The plasma processing apparatus according to claim 2, wherein the heating means is an electric heating belt.

4. The plasma processing apparatus of claim 3 wherein the electrical heating tape comprises at least one set of electrical heating wires disposed around a chamber wall where the non-input and non-output ends of the gas mixing chamber are located.

5. The plasma processing apparatus of claim 1 wherein the gas mixing chamber further comprises:

6. The plasma processing apparatus of claim 5 wherein the process chamber comprises a pedestal, a process chamber cavity, a gas showerhead, and a vacuum pump, the pedestal disposed within the process chamber cavity for carrying a wafer; the gas spray head is arranged at the upper part of the processing cavity and is used for spraying the process gas introduced into the processing cavity to the surface of the wafer placed on the base; the vacuum pump is arranged on one side of the cavity of the processing cavity and used for adjusting the air pressure in the cavity of the processing cavity.

7. The plasma processing apparatus according to claim 6, wherein the pumping line is connected to the vacuum pump.

8. The plasma processing apparatus according to claim 7, wherein at least one pressure control means for controlling the gas pressure of the gas mixing chamber is further provided on the pumping line.

9. The plasma processing apparatus of claim 1, wherein the gas mixing chamber further comprises at least one gas dispersion plate for dispersing the process gas inputted into the gas mixing chamber from the input line into the entire mixing chamber space.

10. The plasma processing apparatus according to claim 9, wherein the dispersion surface of the gas dispersion plate is perpendicular to the gas input direction of the process gas in the gas mixing chamber.

11. The plasma processing apparatus according to claim 9, wherein the number of the gas dispersing plates is two, the gas dispersing plate in the direction near the input end of the gas mixing chamber is a first gas dispersing plate, the gas dispersing plate in the direction near the output end of the gas mixing chamber is a second gas dispersing plate, the dispersing holes of the second gas dispersing plate are smaller than the dispersing holes of the first gas dispersing plate, and the dispersing holes of the second gas dispersing plate are distributed more densely than the dispersing holes of the first gas dispersing plate.