CN118053786A - Upper electrode ring for edge etching, upper electrode assembly and etching equipment - Google Patents

Abstract

The invention discloses an upper electrode ring, an upper electrode assembly and etching equipment, wherein the upper electrode ring comprises a process gas inlet channel and a circumferentially arranged process gas homogenizing groove; the process gas inlet channel is communicated with the process gas homogenizing groove, the process gas inlet channel penetrates through the upper surface of the upper electrode ring, and the process gas homogenizing groove penetrates through the lower surface of the upper electrode ring. The invention can flow in uniform process gas in the edge area of the wafer, and the process gas forms uniform plasma after being ionized so as to etch the edge, the back and the inclined plane sediments of the wafer, thereby improving the edge etching precision.

Description

Upper electrode ring for edge etching, upper electrode assembly and etching equipment

Technical Field

The invention relates to the technical field of semiconductors, in particular to an upper electrode ring for edge etching, an upper electrode assembly and etching equipment.

Background

Typically, the plasma density during etching is relatively low near the edge of the substrate, which may cause polysilicon layers, nitride layers, metal layers, etc. (collectively referred to as byproduct layers) to accumulate on the upper and lower surfaces of the substrate bevel edge. When successive byproduct layers are deposited on the upper and lower surfaces of the substrate bevel edge due to a number of different etching processes, the bond between the byproduct layers and the substrate may be weakened so that the byproduct layers may spall or flake off during substrate transfer, easily falling onto other substrates, contaminating other substrates.

In order to remove the byproduct layer at the bevel edge of the semiconductor wafer, it is necessary to perform edge etching. Wafer edge etching is used to remove deposits that clean the edge, backside, and bevel of a wafer by flowing a process gas into the wafer edge region to generate a plasma. In the prior art, a plurality of dense air holes are arranged on a substrate to send gas into a cavity, but the upper electrode is small in distance from a wafer gap, and the gas in the dense air holes is uneven or locally does not exist in the gap, so that the edge etching effect is affected.

Disclosure of Invention

The invention aims to provide an upper electrode ring, an upper electrode assembly and etching equipment, which can uniformly supply process gas in the edge area of a wafer, and uniform plasma can be formed in the edge area of the wafer by the uniform process gas, so that the edge, the back and inclined surface of the wafer can be effectively cleaned by the uniform plasma.

To achieve the above object, the present invention provides an upper electrode ring for edge etching, comprising: a process gas inlet channel and a circumferentially arranged process gas homogenizing groove; the process gas inlet channel is communicated with the process gas homogenizing groove, the process gas inlet channel penetrates through the upper surface of the upper electrode ring, and the process gas homogenizing groove penetrates through the lower surface of the upper electrode ring.

Optionally, in a cross section where any one of the process gas inlet channels communicates with the process gas distribution groove, the process gas inlet channel is not collinear with the process gas distribution groove.

Optionally, in a section where any one of the process gas inlet channels is communicated with the process gas homogenizing groove, an included angle is formed between the process gas inlet channel and the process gas homogenizing groove, and the included angle is 135 degrees.

Optionally, the process gas inlet channel is a plurality of process gas supply holes.

Optionally, the plurality of process gas supply holes are uniformly arranged at equal intervals in the circumferential direction of the upper electrode ring.

In another aspect, the present invention also provides an upper electrode assembly of an edge etching apparatus, including:

An assembly substrate provided with a process gas supply passage;

A dielectric plate disposed on a lower surface of the mounting substrate in alignment with a center of the mounting substrate;

As described above, the upper electrode ring is disposed on the lower surface of the mounting substrate and the outer periphery of the dielectric plate; wherein the process gas supply channel communicates with the process gas inlet channel.

Optionally, the process gas supply channel comprises: a process gas supply hole, an annular process gas cavity and a plurality of process gas connection holes; the process gas supply holes penetrate through the upper surface of the assembly substrate, and the process gas connection holes penetrate through the lower surface of the assembly substrate; the process gas supply hole and the plurality of process gas connection holes are in communication with the process gas cavity.

Optionally, a plurality of the process gas connection holes are in communication with the process gas inlet channel.

Optionally, the method further comprises: and the insulating ring is arranged between the upper electrode ring and the dielectric plate.

Optionally, the dielectric plate includes: and the shielding gas inlet channel is used for accessing shielding gas.

Optionally, the mounting substrate includes a shielding gas supply channel thereon, which is in communication with the shielding gas inlet channel.

Optionally, the shielding gas inlet passage includes: the device comprises a purging air cavity, a purging air homogenizing groove and a plurality of purging connecting holes; the purging air cavity is a circular concave part at the center of the upper surface of the dielectric plate, and the purging air homogenizing groove penetrates through the lower surface of the dielectric plate; and two ends of the purging connecting hole are respectively communicated with the purging air cavity and the purging air homogenizing groove.

Optionally, the shielding gas inlet channel further includes: and the central air hole is communicated with the purging air cavity and penetrates through the lower surface of the dielectric plate at the center of the dielectric plate.

Optionally, the purging gas homogenizing groove is provided with an annular gas inlet and an annular gas outlet; the diameter of the air inlet is smaller than or equal to that of the air outlet.

In still another aspect, the present invention further provides an etching apparatus, including:

A cavity;

The base is arranged in the cavity and is used for bearing the wafer;

an upper electrode assembly as described above, located above the base;

The process gas homogenizing groove faces the edge of the wafer.

Compared with the prior art, the invention has the following beneficial effects:

The invention can uniformly supply the process gas in the edge area of the wafer, and the uniform process gas forms uniform plasmas in the edge area of the wafer, so that the uniform plasmas can effectively clean the sediment on the edge, the back and the inclined plane of the wafer.

According to the invention, the protective gas is introduced, and the protective gas sweeps from the middle part of the upper surface of the wafer to the edge of the upper surface of the wafer, so that the formed plasma only exists around the edge, the back surface and the inclined surface of the wafer, and only the edge, the back surface and the inclined surface of the wafer are cleaned, and the protective gas does not enter the middle part of the upper surface of the wafer, and therefore, the middle area of the upper surface of the wafer is not damaged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed to illustrate the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an upper electrode ring at a first view angle according to an embodiment of the present invention;

FIG. 2 is a schematic view of the structure of the upper electrode ring at a second view angle according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along the direction A-A in FIG. 2;

FIG. 4 is a schematic view of an upper electrode assembly according to an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of an etching apparatus according to an embodiment of the present invention.

Detailed Description

The terminology used in the present invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe structures, these structures should not be limited by these terms. These terms are only used to distinguish one type of structure from another. For example, a first structure may also be referred to as a second structure, and similarly, a second structure may also be referred to as a first structure, without departing from the scope of the invention.

In addition, in the description of the present invention, the meaning of "a number" means two or more, unless specifically defined otherwise.

The invention provides an upper electrode ring, an upper electrode assembly and etching equipment, wherein uniform process gas can flow in the edge area of a wafer, uniform plasma is formed after the uniform process gas is ionized by high pressure around the uniform process gas, and the uniform plasma can effectively clean the edge, the back and inclined plane sediments of the wafer, so that the etching precision is improved.

The embodiments of the present invention will be specifically described below with reference to the accompanying drawings, which are only for explaining the present invention and should not be construed as limiting the present invention.

Referring to fig. 1 to 3, the present embodiment provides an upper electrode ring 100 for edge etching, which mainly includes: a process gas inlet channel 101 and a circumferentially arranged process gas distribution groove 102. The process gas inlet channel 101 penetrates through the upper surface of the upper electrode ring 100, and the process gas homogenizing groove 102 penetrates through the lower surface of the upper electrode ring 100; the process gas inlet channel 101 communicates with a process gas distribution groove 102. After the process gas inlet channel 101 is connected with the process gas, the process gas is uniformly supplied to the edge area of the wafer through the process gas homogenizing groove 102, plasma uniformly distributed around the edge area of the wafer is formed on the periphery of the wafer, and the uniformly distributed plasma can effectively clean the edge, the back surface and the inclined surface of the wafer.

In this embodiment, it is preferable that, in a cross section where any one of the process gas inlet passages 101 communicates with the process gas distribution groove 102, the process gas inlet passage 101 is not collinear with the process gas distribution groove 102. When the process gas flows to the communication position between the process gas inlet channel 101 and the process gas homogenizing groove 102, the process gas is further diffused due to the partial blocking of the process gas homogenizing groove, and then uniformly flows out of the gas outlet of the process gas homogenizing groove 102, namely, as long as the process gas flows into the process gas homogenizing groove 102 from the process gas inlet channel 101, the process gas can change in flow direction, and the change can promote the process gas to be further diffused in the process gas homogenizing groove 102, so that the uniformity of the supplied gas is improved.

It should be noted that "non-collinear" herein means that, at the communication point between any of the process gas inlet channels 101 and the process gas distribution groove 102, there is a folding angle of not 180 ° between the process gas inlet channels 101 and the process gas distribution groove 102, so as to facilitate diffusion when the process gas flows through.

In this embodiment, more specifically, in a vertical section where any one of the process gas inlet channels 101 communicates with the process gas distribution groove 102, an included angle is formed between the process gas inlet channel 101 and the process gas distribution groove 102. When flowing to the connection between the process gas inlet channel 101 and the process gas homogenizing tank 102, the process gas diffuses in the process gas homogenizing tank and then flows out uniformly from the gas outlet of the process gas homogenizing tank 102.

It should be noted that, the included angle formed between the process gas inlet channel 101 and the process gas homogenizing groove 102 may be designed according to specific process requirements, and the embodiment is not limited specifically. Preferably, the included angle formed between the process gas inlet channel 101 and the process gas distribution groove 102 is 135 degrees, and the included angle 135 degrees includes two cases, that is, in the section plane, the process gas distribution groove 102 rotates 135 degrees around the process gas inlet channel 101 anticlockwise or clockwise.

In the present embodiment, the process gas inlet passage 101 may be a plurality of process gas supply holes. The upper electrode ring 100 in this embodiment is connected to the process gas through a plurality of process gas supply holes, so that the independence and uniformity of the small flow process gas before entering the process gas homogenizing tank 102 can be ensured. It will be appreciated that in some embodiments, the process gas inlet passage 101 may take other forms, such as an annular groove or the like.

In this embodiment, the plurality of process gas supply holes are uniformly arranged at equal intervals in the circumferential direction of the upper electrode ring 100, so that uniformity of the process gas before entering the process gas uniformity groove 102 can be further ensured.

Referring to fig. 4, the present embodiment also provides an upper electrode assembly of an edge etching apparatus, which mainly includes: assembling the substrate 200, the dielectric plate 300, and the upper electrode ring 100 described above; the mounting substrate 200 is provided with a process gas supply passage 201, and the process gas supply passage 201 communicates with the process gas inlet passage 101 on the upper electrode ring 100; the dielectric plate 300 is disposed on the lower surface of the mounting substrate 200 and aligned with the center of the mounting substrate 200; the upper electrode ring 100 is disposed on the lower surface of the mounting substrate 200 and the periphery of the dielectric plate 300. The upper electrode assembly in this embodiment can be configured to uniformly supply the process gas to the edge region of the wafer through the process gas supply channel 201, the process gas inlet channel 101 and the process gas distribution groove 102 in this order by introducing the process gas into the gas inlet of the process gas supply channel 201 on the mounting substrate 200.

In this embodiment, the process gas supply channel 201 mainly includes: a process gas supply hole 2011, an annular process gas chamber 2012, and a plurality of process gas connection holes 2013. The process gas supply hole 2011 penetrates the upper surface of the assembly substrate 200 and communicates with the gas outlet of the supply gas input pipe; a plurality of process gas connection holes 2013 penetrating the lower surface of the assembly substrate 200 and respectively provided corresponding to the plurality of process gas supply holes of the process gas inlet passage 101; the process gas supply hole 2011 and the plurality of process gas connection holes 2013 are in communication with the process gas chamber 2012. After the process gas is introduced, the introduced process gas flows into the process gas inlet passage 101 of the upper electrode ring 100 through the process gas supply hole 2011, the annular process gas chamber 2012, and the plurality of process gas connection holes 2013 in sequence.

In other embodiments, the process gas connection holes of the mounting substrate may be replaced by an annular chamber that communicates the process gas chamber with the process gas inlet passage, which is not specifically limited herein.

In this embodiment, the upper electrode assembly further includes: an insulating ring 500. The insulating ring 500 is disposed between the upper electrode ring 100 and the dielectric plate 300 for isolating the upper electrode ring 100 from the dielectric plate 300. Optionally, the lower surface of the insulating ring 500 protrudes above the upper electrode ring 100 and the dielectric plate 300 to limit plasma from entering the middle region of the wafer during processing.

In this embodiment, the mounting substrate 200 is provided with a shielding gas supply channel 202. The shielding gas supply passage 202 is used for accessing shielding gas.

Preferably, the shielding gas is nitrogen.

In this embodiment, the dielectric plate 300 includes: the shielding gas intake passage 301. The shielding gas inlet channel 301 is used for introducing shielding gas, the introduced shielding gas is supplied to the middle part of the upper surface of the wafer, and the middle part of the upper surface of the wafer is purged to the edge of the upper surface of the wafer, so that plasma only exists at the edge, the back surface and the periphery of the inclined surface of the wafer, and the middle area of the wafer is prevented from being damaged.

In the present embodiment, the shielding gas intake passage 301 includes: a purge air cavity 3011, a purge gas homogenizing groove 3013 and a plurality of purge connecting holes 3012. The purging air cavity 3011 is a circular concave part in the center of the upper surface of the dielectric plate 300, and the purging air homogenizing groove 3013 penetrates through the lower surface of the dielectric plate 300; both ends of the purging connecting hole 3012 are respectively communicated with the purging air cavity 3011 and the purging air homogenizing groove 3013. After the shielding gas is introduced, the shielding gas flows to the middle part of the upper surface of the wafer through the purging air cavity 3011, the purging connecting holes 3012 and the purging gas homogenizing groove 3013 in sequence, and is purged from the middle part of the upper surface of the wafer to the edge of the upper surface of the wafer.

In the present embodiment, the shielding gas intake passage 301 further includes: a central air hole 3014. The central air hole 3014 communicates with the purge air cavity 3011 and penetrates the lower surface of the dielectric plate 300 at the center of the dielectric plate 300. After the shielding gas is introduced, the shielding gas is supplied to the center of the upper surface of the wafer through the purging air cavity 3011, the purging air homogenizing groove 3013 and the purging connecting holes 3012 in sequence, and is purged from the middle of the upper surface of the wafer to the edge of the upper surface of the wafer.

In this embodiment, the purge gas homogenizing groove 3013 has an annular gas inlet and an annular gas outlet, and the diameter of the gas inlet is smaller than or equal to the diameter of the gas outlet. Based on the design, the connected protective gas can diffuse from the middle part of the upper surface of the wafer to the edge of the upper surface of the wafer while flowing downwards, so that the middle part of the upper surface of the wafer is further protected.

Referring to fig. 5, the present embodiment further provides an etching apparatus, which mainly includes: chamber 700, base 800, and the upper electrode assembly described above. Both the base 800 and the upper electrode assembly are disposed inside the cavity 700, and the upper electrode assembly is located above the base 800. The electrostatic chuck of the pedestal carries a wafer W, preferably with the gas outlet of the process gas uniformity tank 102 facing the wafer edge. After the process gas is introduced, the process gas uniformly flows to the edge region of the wafer W through the shielding gas supply passage 202, the process gas inlet passage 101 and the process gas distribution groove 102, and is ionized at a high pressure around the wafer W to form uniform plasma, which can effectively clean the edge, the back surface and the inclined surface of the wafer W.

In this embodiment, the etching apparatus further includes: a process gas input line 401 and a process gas source 402. The two ends of the process gas input pipe 401 are respectively communicated with the gas outlet of the process gas source 402 and the gas inlet of the process gas supply channel 201. The process gas input pipe 401 is externally connected to a process gas, and supplies the externally connected process gas into the process gas supply passage 201 of the mounting substrate 200.

In this embodiment, the etching apparatus further includes: a shielding gas input conduit 601 and a shielding gas source 602. Both ends of the shielding gas input pipe 601 are respectively communicated with the gas outlet of the shielding gas source 602 and the gas inlet of the shielding gas supply passage 202. The shielding gas input pipe 601 is externally connected with shielding gas, and supplies the externally connected shielding gas into the shielding gas supply passage 202 of the mounting substrate 200.

While the present invention 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 invention. Many modifications and substitutions of the present invention will become apparent to those of ordinary skill in the art upon reading the foregoing. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims (15)

1. An upper electrode ring for edge etching, comprising: a process gas inlet channel and a circumferentially arranged process gas homogenizing groove; the process gas inlet channel is communicated with the process gas homogenizing groove, the process gas inlet channel penetrates through the upper surface of the upper electrode ring, and the process gas homogenizing groove penetrates through the lower surface of the upper electrode ring.

2. The upper electrode ring of claim 1, wherein in a cross-section where any of the process gas inlet channels communicates with the process gas uniformity tank, the process gas inlet channels are not collinear with the process gas uniformity tank.

3. The upper electrode ring of claim 2, wherein in any cross section where the process gas inlet channel communicates with the process gas distribution groove, an included angle is formed between the process gas inlet channel and the process gas distribution groove, and the included angle is 135 degrees.

4. The upper electrode ring of claim 1, wherein the process gas inlet passages are process gas supply holes.

5. The upper electrode ring of claim 4, wherein a plurality of the process gas supply holes are uniformly provided at equal intervals in a circumferential direction of the upper electrode ring.

6. An upper electrode assembly of an edge etching apparatus, comprising:

An assembly substrate provided with a process gas supply passage;

A dielectric plate disposed on a lower surface of the mounting substrate in alignment with a center of the mounting substrate;

the upper electrode ring of any one of claims 1-5, the upper electrode ring being disposed on a lower surface of the mounting substrate and a periphery of the dielectric plate; wherein the process gas supply channel communicates with the process gas inlet channel.

7. The upper electrode assembly of claim 6, wherein the process gas supply channel comprises: a process gas supply hole, an annular process gas cavity and a plurality of process gas connection holes; the process gas supply holes penetrate through the upper surface of the assembly substrate, and the process gas connection holes penetrate through the lower surface of the assembly substrate; the process gas supply hole and the plurality of process gas connection holes are in communication with the process gas cavity.

8. The upper electrode assembly of claim 7, wherein a plurality of said process gas connection holes are in communication with said process gas inlet passage.

9. The upper electrode assembly of claim 6, further comprising: and the insulating ring is arranged between the upper electrode ring and the dielectric plate.

10. The upper electrode assembly of claim 6, wherein the dielectric plate comprises: and the shielding gas inlet channel is used for accessing shielding gas.

11. The upper electrode assembly of claim 10, wherein the mounting substrate includes a shielding gas supply passage thereon in communication with the shielding gas inlet passage.

12. The upper electrode assembly of claim 10, wherein the shielding gas inlet passage comprises: the device comprises a purging air cavity, a purging air homogenizing groove and a plurality of purging connecting holes; the purging air cavity is a circular concave part at the center of the upper surface of the dielectric plate, and the purging air homogenizing groove penetrates through the lower surface of the dielectric plate; and two ends of the purging connecting hole are respectively communicated with the purging air cavity and the purging air homogenizing groove.

13. The upper electrode assembly of claim 12, wherein the shielding gas inlet passage further comprises: and the central air hole is communicated with the purging air cavity and penetrates through the lower surface of the dielectric plate at the center of the dielectric plate.

14. The upper electrode assembly of claim 12, wherein the purge gas equalization tank has an annular gas inlet and an annular gas outlet; the diameter of the air inlet is smaller than or equal to that of the air outlet.

15. An etching apparatus, comprising:

A cavity;

The base is arranged in the cavity and is used for bearing the wafer;

the upper electrode assembly according to any one of claims 6 to 14, located above the base;

The process gas homogenizing groove faces the edge of the wafer.