CN114765102A - Plasma cleaning apparatus - Google Patents

Abstract

The present invention is a plasma cleaning device, comprising a cavity, a radio frequency electrode, a stage, an electrode and a first shutter, wherein the first shutter is adjacent to the top of the cavity, and the first shutter has a plurality of first openings to form Non-flat bottom. During the cleaning process of the plasma cleaning equipment, argon ions hit the aluminum substrate on the stage, and the sputtered aluminum reacts with the dirt in the cavity and is adsorbed on the uneven bottom surface of the first shutter to reduce the cavity Chances of dirt sticking to other parts of the body.

Description

Plasma cleaning equipment

technical field

The invention relates to a plasma cleaning device, in particular to a plasma cleaning device that collects dirt through a first shutter.

Background technique

In the semiconductor plasma cleaning process, the plasma cleaning equipment is used to generate plasma, and the argon gas is dissociated to strike the wafer, so as to knock out the dirt on the wafer surface and achieve the effect of wafer cleaning. However, some of the dirt is suspended in the cavity and may fall back to the wafer surface and undergo subsequent processes, such as metallization, with the wafer. If the dirt falls on the future wiring area of the wafer, it will make the wires unable to conduct, thereby reducing the yield of the product.

A method to improve the above problems is to replace the wafer with an aluminum substrate and be impacted by argon ions at a fixed period. The sputtered aluminum can react with the dirt remaining in the cavity and adhere to the shutter of the cavity. Reduces the chance of contamination falling back to the wafer surface. However, since the plasma cleaning equipment uses the coil induced magnetic field to generate plasma for the plasma cleaning process, when the cavity is covered with too much metal, the penetration of the induced magnetic field will be hindered, thereby affecting the generation of the plasma.

One way to improve the problem is to use lateral coils with ceramic vaults, and use a metal frame to mask the dirty aluminum to reduce the chance of metal sticking to the ceramic vault. However, the manufacturing process of the ceramic dome is complicated, time-consuming and expensive.

SUMMARY OF THE INVENTION

Therefore, in order to overcome the deficiencies of the prior art, the embodiment of the present invention provides a plasma cleaning device, which can make the dirty aluminum stuck on the uneven bottom surface of the first shutter of the plasma cleaning device (for example, the first In this way, the probability of contamination floating in other parts of the cavity can be reduced, so as to increase the cleanliness of the wafer.

Based on at least one of the foregoing objectives, the plasma cleaning apparatus provided by the embodiments of the present invention includes a cavity, a radio frequency electrode, a stage, an electrode, and a first shutter. The cavity has a cavity top and an accommodating space, and the radio frequency electrode is connected to the cavity top, the carrier is located in the accommodating space, and the electrode is connected to the carrier. The first shutter is located in the accommodating space of the cavity and adjacent to the top of the cavity, wherein the first shutter has a plurality of first openings to form an uneven bottom surface.

Optionally, the first shutter further includes a plurality of first closing parts, and the first closing parts are adjacent to the top of the cavity and opposite to the first opening, so as to form a plurality of grooves in the first shutter.

Optionally, the cross-sectional area of the first opening is smaller than the cross-sectional area of the first closing portion.

Optionally, the groove further includes a first portion and a second portion, wherein the first opening is located in the first portion, and the second portion is adjacent to the first closing portion, wherein the cross-sectional area of the first portion is smaller than that of the second portion.

Optionally, the cross-sectional area of the groove gradually increases from the first opening toward the first closing portion.

Optionally, the cross-sectional area of the groove gradually decreases from the first opening toward the first closing portion.

Optionally, the cross-sectional area of the groove is tapered to zero from the first opening toward the first closing portion, and the plurality of first openings are closely adjacent to each other, so that the plurality of grooves on the longitudinal section of the first shutter form serrations. shape.

Optionally, the uneven bottom surface of the first shutter is coated with a chemical material, so that the uneven bottom surface forms a concave-convex surface, so as to increase the surface area of the uneven bottom surface.

Optionally, the chemical material is yttria, alumina or ceramics.

Optionally, the plasma cleaning device further includes a second shutter, located between the first shutter and the stage, wherein the second shutter has a plurality of lower openings and a plurality of upper openings, and the plurality of lower openings are connected to the plurality of upper openings. , so as to form a plurality of through holes in the second shutter.

In short, the plasma cleaning device provided by the embodiment of the present invention captures the metal adhered to the dirt through the uneven bottom surface of the first shutter, so as to reduce the probability that the dirt exists in other parts of the cavity, thus increasing the number of wafers. Therefore, it has advantages in markets (eg, semiconductors) that require plasma cleaning equipment and processes.

Description of drawings

FIG. 1 is a schematic diagram of a plasma cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a first shutter according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a first shutter according to another embodiment of the present invention.

FIG. 4 is a schematic diagram of a first shutter according to another embodiment of the present invention.

FIG. 5 is a schematic diagram of a first shutter according to still another embodiment of the present invention.

FIG. 6 is a schematic diagram of a first shutter according to still another embodiment of the present invention.

FIG. 7 is a schematic diagram of a first shutter according to still another embodiment of the present invention.

FIG. 8 is a schematic diagram of a first shutter according to still another embodiment of the present invention.

9 is a schematic perspective view of a first shutter according to still another embodiment of the present invention.

FIG. 10 is a schematic diagram of a first shutter according to still another embodiment of the present invention.

11 is a schematic perspective view of a first shutter according to still another embodiment of the present invention.

FIG. 12 is a schematic diagram of a first shutter according to still another embodiment of the present invention.

13 is a schematic diagram of a plasma cleaning apparatus according to still another embodiment of the present invention.

Description of reference numerals: 1, 2 - plasma cleaning equipment; 11 - chamber; 111 - top of chamber; 113 - process gas inlet; 13 - stage; 131 - cooling line; 15, 25, 35, 45, 55 , 65, 75, 85, 95, 105 - the first shutter; 151, 251, 351, 451, 551, 651, 751, 851, 951, 1051 - the first opening; 153, 253, 353, 453, 553 - The first closing part; 155, 255, 355, 455, 555 - groove; 15S, 65S, 75S - non-flat bottom surface; 257 - first part; 259 - second part; 355W, 455W, 555W - groove side wall; 652, 752 - the second opening; 653, 753 - through holes; A151, A251, A351, A451, A551 - the cross-sectional area of the first opening; A153, A253, A353, A453 - the cross-sectional area of the first closed part; A257- Cross-sectional area of the first part; A259-cross-sectional area of the second part; C851, C951, C1051-circular opening; D651, D751-lower opening; E1-RF electrode; E2-electrode; L951, L1051-long opening; S -Accommodating space; S75-second shutter; U652, U752-upper opening; W-substrate.

Detailed ways

In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail by the following specific embodiments and the accompanying drawings, which are described below.

First, please refer to FIG. 1 , which is a schematic diagram of a plasma cleaning apparatus according to an embodiment of the present invention. The plasma cleaning apparatus 1 provided by the present invention includes a cavity 11 , a radio frequency electrode E1 , a stage 13 , an electrode E2 and a first shutter 15 . The cavity 11 has a cavity top 111 and an accommodating space S, and the material of the cavity top 111 is, for example, but not limited to, ceramics.

A carrier 13 is disposed in the accommodating space S of the cavity 11 , and the carrier 13 is used for carrying at least one substrate W. The plasma cleaning apparatus 1 may further be provided with a cooling line 131 , and the cooling line 131 is connected to the stage 13 (eg, disposed inside the stage 13 ) to adjust the temperature of the substrate W.

In a semiconductor pre-clean process, the substrate W is a wafer. Dirt on the wafer can be bombarded by the plasma during the pre-clean process, while the contamination and by-products (eg, Al2O3, SiO2, Silicon Nitride, carbon, organic compounds, polluting gases, etc.) Attached or suspended in the cavity 11 . When cleaning the plasma cleaning apparatus 1, a metal substrate (eg, an aluminum substrate) is used as the substrate W, and the aluminum can be sputtered out by the plasma and react with or cause the contamination and by-products Attached to sputtered aluminum.

Specifically, the stage 13 is connected to the electrode E2, and the electrode E2 is located above the stage 13, so that the stage 13 carries the substrate W through the electrode E2. The top 111 of the cavity is connected to the radio frequency electrode E1 , and the radio frequency electrode E1 and the electrode E2 can generate a potential difference in the accommodating space S of the cavity 11 .

The sidewall of the cavity 11 also has a process gas inlet 113 , so that a process gas (eg, argon) enters the accommodating space S of the cavity 11 through the process gas inlet 113 . When the plasma cleaning device 1 is cleaned, the radio frequency electrode E1 and the electrode E2 generate a potential difference in the cavity 11 and make the electrons have energy. When the electrons strike the argon gas introduced into the cavity 11 , the argon gas can be dissociated into argon ions, so that a high-density plasma is generated in the cavity 11 . After the plasma in the cavity 11 is accelerated, the argon ions strike the aluminum substrate and the aluminum is sputtered out, so as to react with the contamination and by-products or make the contamination and by-products adhere to the sputtered aluminum.

The first shutter 15 is located in the accommodating space S and is adjacent to the top 111 of the cavity. The first shutter 15 has a plurality of first openings 151 to form an uneven bottom surface 15S, and the dirt attached to the aluminum surface can be removed by the non-flat bottom surface 15S. The flat bottom surface 15S is captured to reduce the probability of being suspended in the accommodating space S of the cavity 11 . Since the first shutter 15 has a non-flat bottom surface 15S, the surface area of which is larger than that of the flat bottom surface, that is, the surface area for adsorbing dirt is larger, so the frequency of replacing the first shutter 15 can be reduced, and thus, the plasma cleaning equipment can be extended. 1 cleaning cycle. The material of the first shutter 15 may be quartz, ceramic, silicon carbide or alumina, but the present invention is not limited thereto.

The plasma cleaning apparatus 1 may further include a cooling channel connected to the top of the cavity 111 (not shown) to reduce the temperature of the cavity 11 to delay the diffusion of the dirt in the accommodating space S to the substrate W.

In one embodiment, the first shutter 15 has a plurality of first openings 151 and a plurality of first closing portions 153 . The first closing portion 153 is adjacent to the cavity top 111 and is opposite to the first opening 151 to form a plurality of grooves 155 in the first shutter 15 . The first opening 151 of the groove 155 faces the direction of the substrate W to accommodate the sputtered and dirty aluminum.

The uneven bottom surface 15S or the grooves 155 of the first shutter 15 may be coated with a chemical material, wherein the chemical material may be yttrium oxide, alumina or ceramics. The purpose of coating the chemical material on the uneven bottom surface 15S or the groove 155 is to create an uneven surface (eg, a concave-convex surface) to increase the surface area of the uneven bottom surface 15S or the groove 155, so that it can be more easily captured or stuck and carried Dirty aluminum.

The first shutter 15 can have various shapes. Please refer to FIG. 2 , the first shutter 15 has a plurality of grooves 155 to form a non-flat bottom surface 15S, and the cross-sectional area of the grooves 155 is directed from the first opening 151 toward the bottom surface 15S. The direction of the first closing portion 153 remains unchanged, that is, the cross-sectional area A151 of the first opening is equal to the cross-sectional area A153 of the first closing portion.

Please refer to FIG. 3 , which is a schematic diagram of a first shutter according to another embodiment of the present invention. The first shutter 25 has a plurality of first openings 251 and a plurality of first closing parts 253 , and the first closing parts 253 and the first openings 251 are opposite to each other, so as to form a plurality of grooves 255 in the first shutter 25 , wherein the first closing part 253 and the first opening 251 are opposite to each other. The cross-sectional area A251 of an opening is smaller than the cross-sectional area A253 of the first closing portion.

Specifically, the groove 255 includes a first portion 257 and a second portion 259 , the first opening 251 is located at the first portion 257 , and the second portion 259 is adjacent to the first closing portion 253 . In the longitudinal section of the first shutter 25, the first part 257 and the second part 259 are both rectangular, wherein the cross-sectional area A257 of the first part is smaller than the cross-sectional area A259 of the second part, so that the groove 255 is T-shaped, so , the dirt is easily stuck on the second portion 259 with a larger cross-sectional area, and is not easily dropped from the first opening 251 with a smaller cross-sectional area. Likewise, the grooves 255 can be sprayed with ceramic or coated with yttrium oxide or aluminum oxide to increase the surface area of the grooves 255 and enhance the ability of the first shutter 25 to capture dirt.

In other embodiments, the groove 255 may not be divided into the first part 257 and the second part 259 . Please refer to FIG. 4 , which is a schematic diagram of a first shutter according to another embodiment of the present invention. As shown in FIG. 4 , the first shutter 35 has a plurality of first openings 351 and a plurality of first closing parts 353 , and the first The closing portion 353 and the first opening 351 are opposite to each other to form a plurality of grooves 355 in the first shutter 35 , wherein the cross-sectional area A351 of the first opening is smaller than the cross-sectional area A353 of the first closing portion.

Specifically, the cross-sectional area of the groove 355 gradually increases from the first opening 351 toward the first closing part 353 , so that a chamfer 355A is formed between the groove side wall 355W of the groove 355 and the first closing part 353 , wherein The range of the lead angle 355A is 40 to 90 degrees. When the chamfering angle 355A of the groove 355 is not a right angle, dirt is not easily dropped from the first opening 351 with a smaller cross-sectional area. Likewise, the grooves 355 can be sprayed with ceramic or coated with yttrium oxide or aluminum oxide to increase the surface area of the grooves 355 and enhance the ability of the first shutter 35 to capture dirt.

In other embodiments, the grooves 355 may have other shapes. Please refer to FIG. 5 , which is a schematic diagram of a first shutter according to still another embodiment of the present invention. As shown in FIG. 5 , the first shutter 45 has a plurality of first openings 451 and a plurality of first closing parts 453 , and the first closing parts 453 and the first openings 451 are opposite to each other, so as to form a plurality of grooves in the first shutter 45 455, wherein the cross-sectional area A451 of the first opening is greater than the cross-sectional area A453 of the first closing portion.

Specifically, the cross-sectional area of the groove 455 gradually decreases from the first opening 451 toward the first closing part 453 , so that a chamfer 455A is formed between the groove side wall 455W of the groove 455 and the first closing part 453 , wherein The range of the lead angle 455A is 90 to 130 degrees. When the cross-sectional area A451 of the first opening is larger than the cross-sectional area A453 of the first closing portion, dirt is more easily accommodated in the groove 455 . Likewise, the grooves 455 may be sprayed with ceramic or coated with yttrium oxide or aluminum oxide to increase the surface area of the grooves 455 and enhance the ability of the first shutter 45 to capture dirt.

In other embodiments, the cross-sectional area A453 of the first closed portion may be zero. Please refer to FIG. 6 , which is a schematic diagram of a first shutter according to still another embodiment of the present invention. As shown in FIG. 6 , the cross-sectional area of the groove 555 tapers from the first opening 551 toward the first closing portion 553 to zero. Specifically, the cross-sectional area of the first closing portion 553 is zero, so that the two side walls 555W of the groove 555 have a contact point. Furthermore, the plurality of first openings 551 may be adjacent to each other, so that the plurality of grooves 555 of the first shutter 55 form a sawtooth shape. In other embodiments, the plurality of first openings 551 may not be immediately adjacent to each other (not shown). Likewise, the grooves 555 can be sprayed with ceramic or coated with yttrium oxide or aluminum oxide to increase the surface area of the grooves 555 and enhance the ability of the first shutter 55 to capture dirt.

In other embodiments, the first shutters 15-55 may not have the first closing parts 153-553. Please refer to FIG. 7 , which is a schematic diagram of a first shutter according to still another embodiment of the present invention. As shown in FIG. 7 , the first shutter 65 has a plurality of first openings 651 (lower openings D651 ) to form an uneven bottom surface 65S, and has a plurality of second openings 652 (upper openings U652 ), wherein the upper openings U652 and the lower openings D651 communicate with each other to form through holes 653 . In the longitudinal section of the first shutter 65, the through hole 653 is rectangular, but the present invention is not limited thereto. Likewise, the first shutter 65 may be sprayed with ceramic or coated with yttrium oxide or alumina to increase the surface area of the uneven bottom surface 65S and enhance the ability of the first shutter 65 to capture dirt.

Please refer to FIG. 8 , which is a schematic diagram of a first shutter according to still another embodiment of the present invention. As shown in FIG. 8 , the second opening 752 (upper opening U752 ) and the first opening 751 (lower opening D751 ) of the first shutter 75 communicate with each other to form a through hole 753 while in the longitudinal section of the first shutter 75 , the through hole 753 is trapezoidal. In other embodiments, the through holes 753 may also be T-shaped (not shown). Likewise, the first shutter 75 can be sprayed with ceramic or coated with yttrium oxide or aluminum oxide to increase the surface area of the uneven bottom surface 75S and enhance the ability of the first shutter 75 to capture dirt.

When the plasma cleaning apparatus 1 is provided with the first shutters 15 - 75 , the dirt-carrying aluminum can be not adhered (or only partially adhered) to the cavity top 111 . Most of the aluminum carrying dirt is captured by the first shutters 15-75, and it is difficult to form a continuous surface. In this way, the cavity 11 will not be covered by too much metal, so it is difficult to affect the penetration of the induced magnetic field, thereby stabilizing the generation of plasma .

Next, please refer to FIG. 9 . FIG. 9 is a three-dimensional schematic diagram of a first shutter according to still another embodiment of the present invention. As shown in FIG. 9 , the first opening 851 of the first shutter 85 is a circular opening C851 , and the plurality of first openings 851 are arranged in concentric circles and radial shapes. The shape and arrangement of the first openings 151 to 751 in any of the foregoing embodiments may be the same or similar to those in FIG. 9 .

In other embodiments, the first opening 851 may not be completely the circular opening C851. Please refer to FIG. 10 and FIG. 11 . FIGS. 10 and 11 are schematic diagrams of a first shutter according to still another embodiment of the present invention. The first opening 951 of the first shutter 95 can be a circular opening C951 and an elongated opening L951, and the elongated opening L951 can form a groove, wherein the circular opening C951 and the elongated opening L951 can be staggered and present concentric circles and radial. The shape and arrangement of the first openings 151 to 751 in any of the foregoing embodiments may be the same or similar to those in FIGS. 10 and 11 .

In other embodiments, the circular opening C951 and the elongated opening L951 may communicate with each other. Please refer to FIG. 12 , which is a schematic diagram of the first shutter according to still another embodiment of the present invention. The circular opening C1051 and the elongated opening L1051 of the first shutter 105 communicate with each other and present concentric circles and radial shapes.

In other embodiments, the plasma cleaning apparatus 1 may have a plurality of first shutters. Please refer to FIG. 13 , which is a schematic diagram of a plasma cleaning apparatus according to still another embodiment of the present invention. As shown in FIG. 13 , the plasma cleaning apparatus 2 is substantially the same as the previous embodiment, and the difference is only that the plasma cleaning apparatus 2 further has a second shutter S75 . The second shutter S75 is located between the first shutter 15 and the stage 13, wherein the second shutter S75 has a plurality of lower openings D751 and a plurality of upper openings U752, and the lower opening D751 communicates with the upper opening U752, so that the second shutter S75 has a plurality of lower openings D751 and a plurality of upper openings U752. The shutter shape S75 is formed into a plurality of through holes.

When the plasma cleaning device 2 has two shutters 15, S75, the dirt-carrying aluminum can be partially attached to the second shutter S75, and the dirt that penetrates the through holes of the second shutter S75 can be attached to the second shutter S75. A shutter 15. The through holes of the second shutter S75 and the grooves 155 of the first shutter 15 may be staggered, but the invention is not limited thereto.

In one embodiment, the cleaning of the plasma cleaning apparatus 1 is performed by replacing the wafer with an aluminum substrate at a fixed period. In other embodiments, the cleaning of the plasma cleaning apparatus 1 may also be performed simultaneously with the wafer pre-cleaning process. The electrodes E2 of the plasma cleaning devices 1 and 2 may be surrounded by an aluminum ring (not shown in the figure). When the wafer pre-cleaning process is performed, the plasma can bombard the wafer and the aluminum ring at the same time. Dirt and by-products sputtered from the round surface can combine with the aluminum bombarded from the aluminum ring and be captured by the shutter.

In summary, compared with the prior art, the technical effects of the plasma cleaning device according to the embodiment of the present invention are described as follows.

In the prior art, in the pre-cleaning process of the wafer, part of the dirt will fall back to the surface of the wafer, or even fall into the future wiring area of the wafer, which will make the wires unable to conduct, thereby reducing the yield of the product. . On the other hand, the plasma cleaning device of the present invention can accommodate dirt through the uneven surface of the shutter. Since the surface area of the uneven surface of the shutter is large, it can accommodate a larger amount of dirt and prolong the cleaning cycle. Furthermore, the manufacturing cost of the shutter is not high, so the present invention provides a low-cost plasma cleaning device that can achieve effective cleaning.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Modifications should be included in the scope of the patent application of the present invention.

Claims (10)

1. A plasma cleaning device, wherein the plasma cleaning device comprises: a cavity with a cavity top and an accommodating space; a radio frequency electrode connected to the top of the cavity; a stage, located in the accommodating space, and used for carrying at least one substrate; an electrode connected to the stage; and A first shutter is located in the accommodating space and adjacent to the top of the cavity, and the first shutter has a plurality of first openings to form an uneven bottom surface. 2 . The plasma cleaning apparatus according to claim 1 , wherein the first shutter further comprises a plurality of first closing parts, and the first closing parts are adjacent to the top of the cavity and connected to the top of the cavity. 3 . The first openings are opposite to each other to form a plurality of grooves in the first shutter. 3. The plasma cleaning apparatus according to claim 2, wherein a cross-sectional area of the first opening is smaller than a cross-sectional area of the first closing portion. 4 . The plasma cleaning apparatus according to claim 2 , wherein the groove further comprises a first part and a second part, the first opening is located in the first part, and the second part is opposite to the second part. 5 . Adjacent to the first closing portion, wherein the cross-sectional area of the first portion is smaller than the cross-sectional area of the second portion. 5 . The plasma cleaning apparatus according to claim 2 , wherein the cross-sectional area of the groove gradually increases from the first opening toward the first closing portion. 6 . 6 . The plasma cleaning apparatus according to claim 2 , wherein a cross-sectional area of the groove gradually decreases from the first opening toward the first closing portion. 7 . 7 . The plasma cleaning apparatus according to claim 6 , wherein the cross-sectional area of the groove is tapered from the first opening toward the first closing portion to zero, and a plurality of the The first openings are in close proximity to each other, so that the plurality of the grooves of the longitudinal section of the first shutter form a zigzag shape. 8 . The plasma cleaning apparatus according to claim 1 , wherein the uneven bottom surface of the first shutter is coated with a chemical material, so that the uneven bottom surface forms a concave and convex surface, so as to increase the The surface area of the uneven bottom surface. 9. The plasma cleaning apparatus of claim 8, wherein the chemical material is yttrium oxide, aluminum oxide or ceramic. 10. The plasma cleaning apparatus according to claim 1, wherein the plasma cleaning apparatus further comprises a second shutter, located between the first shutter and the carrier, wherein the The second shutter has a plurality of lower openings and a plurality of upper openings, and the lower openings communicate with the plurality of upper openings to form a plurality of through holes in the second shutter.

Images