TWI834075B - Confinement ring assembly, plasma treatment device and exhaust control method thereof - Google Patents

Abstract

The invention discloses a constraint ring assembly, a plasma processing device and an exhaust control method thereof. The constraint ring assembly includes: a constraint ring. The constraint ring has a plurality of gas channels for discharging gas to the exhaust area below the constraint ring. ; A plurality of gas channel adjusting members are located below the constraint ring. Each gas channel adjusting member includes a blocking member. The blocking member can move relative to the constraining ring to adjust the gap of the gas channel of the constraining ring to divide the entire constraining ring. It is a plurality of adjustment areas. The invention can use the microscopic debugging process to change the gap of the gas channel of the constraint ring, adjust the environment of the cavity in different areas, improve the asymmetry of the process area, and further improve the process uniformity of the substrate.

Description

Confinement ring assembly, plasma processing device and exhaust control method thereof

The present invention relates to devices in the semiconductor field, and in particular to a confinement ring assembly, a plasma processing device and an exhaust control method thereof.

The plasma processing device utilizes the working principle of a vacuum reaction chamber to process semiconductor substrates and plasma panel substrates. The working principle of the vacuum reaction chamber is to introduce reaction gas containing appropriate etchant or deposition source gas into the vacuum reaction chamber, and then input radio frequency energy into the vacuum reaction chamber to excite the reaction gas to ignite and maintain the plasma. In order to respectively etch the material layer on the surface of the substrate or deposit the material layer on the surface of the substrate, and then process the semiconductor substrate and plasma panel. For example, capacitive plasma reactors, in which radiofrequency power is applied to one or both of two electrodes, have been widely used to process semiconductor substrates and display panels. A capacitive discharge is formed between a pair of parallel electrodes.

Plasma is diffusive, and while most of the plasma will remain in the treatment area between a pair of electrodes, some may fill the entire working chamber. For example, plasma may leak into non-processing areas beneath the vacuum chamber. If plasma reaches these areas, corrosion, deposition, or erosion may ensue, which may cause particle contamination inside the chamber, thereby reducing the reusability of the plasma treatment device and potentially shortening the chamber or reaction chamber. The working life of components. If the plasma is not confined within a certain working area, charged particles will hit unprotected areas, resulting in impurities and contamination on the surface of the semiconductor substrate.

Therefore, in the industry, a confinement ring is generally installed in the plasma treatment device to control the discharge of the used reaction gas and to electrically neutralize the charged particles in the reaction gas when they pass through the plasma confinement device. Thus, the discharge is basically restricted within the treatment area to prevent possible cavity contamination problems during use of the plasma treatment device.

However, those with ordinary knowledge in the art should understand that the plasma process area within the plasma processing device will produce non-uniform phenomena, and the non-uniformity of the process area will further lead to process non-uniformity of the substrate. As we all know, the substrate The non-uniformity of the wafer manufacturing process is a core technical problem that needs to be solved in this field, and the present invention is proposed based on this.

The purpose of the present invention is to provide a constraint ring assembly, a plasma processing device and an exhaust control method thereof, which utilizes a microscopic debugging process to change the gap of the constraint ring gas channel, adjust the environment of the cavity in different regions, and improve the problem of asymmetry in the process area. , and further improve the process uniformity of the substrate.

In order to achieve the above objectives, the present invention is achieved through the following technical solutions:

The invention provides a constraint ring assembly for a plasma processing device. The plasma processing device includes a reaction chamber. A base for supporting a substrate is provided in the reaction chamber. The constraint ring assembly is arranged around the periphery of the base and the reaction chamber. Between the side walls, the constraint ring assembly includes: a constraint ring, the constraint ring has a plurality of gas channels for discharging gas to the exhaust area below the constraint ring; a plurality of gas channel adjusters, located below the constraint ring, each gas The channel adjustment member includes a blocking member that can move relative to the constraint ring to adjust the gap of the gas channel of the constraint ring to divide the entire constraint ring into a plurality of adjustment areas.

Further, a plurality of gas channel adjusting members are arranged along the circumferential direction of the constraining ring.

Further, the blocking member can move in a horizontal direction relative to the constraining ring to adjust the gap of the gas channel, and/or the blocking member can move in a vertical direction relative to the constraining ring to adjust the gas resistance of the gas channel.

Further, the gas channel adjusting member further includes: a movable frame, which is vertically arranged on the circumferential outside of the constraint ring; a support frame, which is used to support the blocking member and is connected to the movable frame; the movable frame is connected to the driving device and passes through The support frame drives the blocking member to move.

Further, the constraint ring includes a plurality of guide rings arranged in a concentric circle, and a plurality of connectors connecting the guide rings. The gas channel is an annular groove-shaped channel between adjacent guide rings; The blocking members corresponding to an adjustment area are distributed in a fan shape, and the blocking members include a plurality of arc-shaped members, corresponding to at least part of the gas channels in the adjustment area; the arc-shaped members move radially below the gas channel, and the adjusting arc-shaped members have a negative impact on the gas channel. Block the range to adjust the gap of the gas channel.

Further, the support frame is correspondingly arranged below the connecting frame; the movable frame is arranged vertically in the outermost guide ring.

Further, the connecting frames are distributed at intervals along the circumferential direction of the constraining ring, and are respectively arranged in the radial direction; each adjustment area is symmetrical with respect to the connecting frame of the adjustment area.

Further, the material of the gas channel adjusting member is the same as or different from the material of the constraint ring.

Further, the lengths of the plurality of arc-shaped members of the blocking member decrease sequentially from outside to inside.

Further, the length of the first arc-shaped member is equal to the length of the second arc starting from the outer ring of the constraint ring in the adjustment area corresponding to the blocking member.

Further, the driving device includes one of a motor device, a hydraulic device or a pneumatic device.

Based on the above purpose, the present invention further provides a plasma processing device, which includes: a reaction chamber, a base for supporting the substrate is provided in the reaction chamber; the above-mentioned constraint ring assembly, the constraint ring assembly is arranged around the periphery of the base and the reaction chamber between the side walls of the cavity.

Based on the above purpose, the present invention further provides an exhaust control method for a plasma treatment device, which includes the following steps: providing the above-mentioned plasma treatment device; and when it is necessary to adjust the reaction chamber environment in the plasma treatment device, using The driving device drives the gas channel adjusting member to move and adjust the gap of the gas channel; by adjusting the gap of the gas channel, the gas flow distribution in the exhaust area corresponding to the lower part of the gas channel adjusting member is adjusted.

Further, the driving device is used to drive the gas channel adjusting member to move, and adjusting the gap of the gas channel includes: the driving device drives the gas channel adjusting member to move downward, so that the blocking member is separated from the constraint ring; the driving device drives the gas channel adjusting member to move radially, The gap of the gas channel is made larger or smaller; the driving device drives the gas channel adjusting member to move upward, so that the blocking member contacts the restraining ring.

Compared with the prior art, the present invention has the following advantages:

The present invention changes the gap of the gas channel of the constraint ring through the microscopic debugging process, and can adjust the environment of the cavity in different regions, improve the asymmetry of the process area, and further improve the process uniformity of the substrate.

The invention can cooperate with the vacuum pump interface to improve the air pumping efficiency and effectively reduce the impurity particles in the machine.

In order to understand the characteristics, content and advantages of the present invention and the effects it can achieve, the present invention is described in detail below in conjunction with the accompanying drawings and in the form of embodiments. The drawings used are only for illustration. and auxiliary instructions are not necessarily the actual proportions and precise configurations after implementation of the present invention. Therefore, the proportions and configuration relationships of the attached drawings should not be interpreted to limit the scope of protection of the present invention in actual implementation.

The inventive mechanism of the present invention is to adjust the gap of the gas channel of the constraint ring by arranging a plurality of gas channel adjustment members below the constraint ring. Each gas channel adjuster includes a blocking member. The blocking member can move relative to the constraint ring to adjust the gas channel gap of the constraint ring. The entire constraint ring is divided into a plurality of adjustment areas. Figure 1 illustrates a process area in a plasma processing apparatus prior to use of the present invention, as shown in Figure 1, as it illustratively connects the confinement ring 16 directly or indirectly to ground on the right side of the chamber shown, at The process area A near the ground (the left side of the plasma processing device 1 shown) is "held up" higher than the other side of the chamber without the ground terminal 17 (the plasma processing device 1 shown). Right) Plasma concentration is lower. As a result, the process rate of the edge portion of the substrate W to be processed on one side of the ground terminal 17 in Figure 1 is reduced, while the process rate on the other side is relatively high. The substrate W obtained by the process will inevitably produce uniformity. defect.

Please refer to FIG. 2 , which is a schematic structural diagram of a plasma processing device using the confinement ring assembly of the present invention. The plasma treatment device 1 shown in Figure 2 has a reaction chamber 10. The reaction chamber 10 is basically cylindrical, and the side walls of the reaction chamber 10 are basically vertical. The reaction chamber 10 has an upper electrode 11 and a lower electrode arranged parallel to each other. 13. Generally speaking, the area between the upper electrode 11 and the lower electrode 13 is the processing area B, and the processing area B will generate high-frequency energy to ignite and maintain the plasma. The lower electrode 13 includes a base 131, and a substrate W to be processed is placed above the base 131. The substrate W may be a semiconductor substrate to be etched or processed or a glass panel to be processed into a flat panel display. The reaction gas is input into the reaction chamber 10 from the gas source 12, and one or a plurality of radio frequency power sources 14 can be applied to the lower electrode 13 individually or simultaneously to the upper electrode 11 and the lower electrode 13 to deliver radio frequency power. to the lower electrode 13 or the upper electrode 11 and the lower electrode 13 , thereby generating a large electric field inside the reaction chamber 10 . Most of the electric field lines are contained in the process area A between the upper electrode 11 and the lower electrode 13 . This electric field accelerates a small amount of electrons existing inside the reaction chamber 10 , causing them to collide with gas molecules of the input reaction gas. These collisions result in ionization of the reaction gas and excitation of plasma, thereby generating plasma within the reaction chamber 10 . The neutral gas molecules of the reacting gases lose electrons when they are subjected to these strong electric fields, leaving behind positively charged ions. The positively charged ions accelerate toward the lower electrode 13 and combine with the neutral substances in the substrate W to be processed to excite the substrate W for processing, that is, etching, deposition, etc. An exhaust area is provided at a suitable position of the plasma processing device 1. The exhaust area is connected to an external exhaust device (for example, a vacuum pump 15) to remove the used reaction fluid during the treatment process. Gas and by-product gas extraction processing area B.

In one application scenario, since the constraint ring 16 is connected to the ground terminal 17 near the right cavity of the plasma processing device 1 as shown in Figure 1, the plasma process area A is "supported" above the right constraint ring 16. "From a spatial perspective, the plasma process area A presents an asymmetric cloud shape. Specifically, near the constraint ring 16 connected to the ground terminal 17, the process area A is "lifted up", while far away from the ground terminal 17 Near the constraint ring 16 of 17, the process area A extends to the bottom of the substrate. Therefore, the plasma concentration of the substrate area Wa at this area is low. In contrast, the plasma concentration corresponding to the substrate region Wb on the other side in the horizontal direction of the substrate W is higher.

It should be noted that although the constraining ring 16 in the figures is directly connected to the ground terminal 17, those with ordinary skill in the art should understand that the constraining ring 16 can be selectively connected to the ground terminal 17 indirectly, for example, through A connecting component (not shown) is connected to the ground terminal 17 .

Figure 3 is a bottom view of the constraint ring of the present invention. As shown in Figure 3, the above-mentioned constraint ring 16 includes a plurality of guide rings 162 arranged concentrically, and a plurality of connecting frames 163 connecting the guide rings 162. The gas channel 161 is an annular groove-shaped channel between adjacent flow guide rings 162, and along the circumferential direction of the constraint ring 16, the entire constraint ring 16 is virtually divided into a plurality of adjustment areas 160.

FIG. 4 is a schematic diagram of a confinement ring assembly used in a plasma processing device. Referring to FIG. 4 and in conjunction with FIGS. 2 and 3 , the confinement ring assembly provided by the present invention is arranged around the periphery of the base 131 and the side wall of the reaction chamber 10 During the period, the constraint ring assembly includes a constraint ring 16 and a plurality of gas channel adjusting members 2, wherein the constraining ring 16 has a plurality of gas channels 161 for discharging gas to the exhaust area below the constraint ring 16, and a plurality of gas channel adjusting members 2 2 is located below the constraint ring 16. Specifically, a gas channel adjustment member 2 can be provided below the adjustment area 160 of the above-mentioned constraint ring 16. Each gas channel adjustment member 2 includes a blocking member 21, and the blocking member 21 can move relative to the constraint ring 16. , the gap of the gas channel 161 of the constraint ring 16 is adjusted to divide the entire constraint ring 16 into a plurality of adjustment areas 160 .

It should be noted that the above-mentioned blocking member 21 can divide the entire confinement ring 16 into a plurality of adjustment areas 160 in equal proportions to adjust the plasma concentration environment in the reaction chamber 10 by area. For example, when the plasma concentration in the substrate area Wa When the plasma concentration of the gas channel adjustment member 2 is lower, the blocking member 21 of the gas channel adjustment member 2 is controlled to move, so that the gap of the gas channel 161 of the confinement ring 16 is reduced; and/or when the plasma concentration of the substrate area Wb is higher, the gas channel adjustment is controlled. The blocking member 21 of the member 2 moves so that the gap of the gas channel 161 of the confinement ring 16 increases.

Further, a plurality of gas channel adjusting members 2 are arranged along the circumferential direction of the constraining ring 16 , and the blocking member 21 can move relative to the constraining ring 16 in a horizontal or vertical direction to adjust the gap of the gas channel 161 .

Figures 5a to 5d are structural schematic diagrams of adjusting the gap of the gas channel according to the present invention. As shown in Figure 5a, in a specific embodiment, the gas channel adjustment member 2 further includes: a movable frame 22, which is vertically arranged on the constraint ring 16 the circumferential outside; the support frame 23 is used to support the blocking member 21 and is connected to the movable frame 22; the movable frame 22 is connected to the driving device (not shown), and drives the blocking member 21 to move through the supporting frame 23.

Referring to Figures 3 and 4, the constraint ring 16 includes a plurality of guide rings 162 arranged concentrically, and a plurality of connecting frames 163 connecting the guide rings 162. The gas channel 161 is between adjacent guide rings 162. Annular groove-shaped channel; the blocking member 21 corresponding to an adjustment area 160 of the constraint ring 16 is distributed in a fan shape, and the blocking member 21 includes a plurality of arc-shaped members, corresponding to at least a part of the gas channel 161 of this adjustment area 160; arc The arc-shaped member moves radially below the gas channel 161, and the range of the arc-shaped member blocking the gas channel 161 is adjusted to adjust the gap of the gas channel 161. In this way, by adjusting the gap of the gas channel 161 in each area, the entire constraint ring 16 can flow The airflow rates are similar.

It should be noted that the support frame 23 is correspondingly arranged below the connecting frame 163; the movable frame 22 is arranged vertically in the outermost guide ring 162. The connecting frames 163 are distributed at intervals along the circumferential direction of the constraining ring 16 , and are arranged along the radial direction; each adjustment area 160 is symmetrical with respect to the connecting frame 163 of the adjustment area 160 .

The material of the gas channel adjusting member 2 is the same as the material of the constraint ring 16, which can prevent the cavity reaction by-products from etching the gas channel adjusting member 2. Furthermore, the material of the constraint ring 16 includes insulating materials, such as quartz, alumina or coated with The conductor aluminum is a corrosion-resistant material, as long as it can ensure that the potential is floating.

Preferably, referring to FIG. 4 , the lengths of the plurality of arc-shaped members of the blocking member 21 decrease sequentially from outside to inside, and the length of the first arc-shaped member 210 and the constraint ring in the adjustment area 160 corresponding to the blocking member 21 The second arc 1620 starting from the 16 outer circle has the same length. The above structure can better prevent damage caused by contact and friction between the blocking members 21 of the gas channel adjusting member 2 of the two adjacent gas channels 161 during horizontal movement.

The driving device includes one of a motor device, a hydraulic device or a pneumatic device.

It should be noted that the driving device has mature technical support in the existing technology (for example, using GUI computer control or manual control). For the sake of concise description, the details will not be described here.

The plasma processing device provided by the embodiment of the present invention has the same technical features as the constraint ring assembly provided by the above embodiment, so it can also solve the same technical problem and achieve the same technical effect.

Please refer to FIG. 6 , which is a flow chart of the exhaust gas control method of the plasma treatment device of the present invention. As shown in Figure 6, the third embodiment of the present invention provides an exhaust control method for a plasma treatment device, which includes the following steps:

Step S61: Provide a plasma processing device;

Step S62: When it is necessary to adjust the reaction chamber environment in the plasma treatment device, use the driving device to drive the gas channel adjustment member to move and adjust the gap of the gas channel;

Step S63: Adjust the gas flow distribution in the exhaust area corresponding to the lower part of the gas channel adjustment member by adjusting the gap of the gas channel.

Further, the driving device is used to drive the movement of the gas channel adjustment member, and adjusting the gap of the gas channel further includes the following steps:

The driving device drives the gas channel adjusting member to move downward, causing the blocking member to separate from the constraining ring (see Figure 5a and Figure 5b); by adjusting the vertical distance between the blocking member and the constraining ring, the air resistance of the blocking member to the constraining ring can be achieved Adjustment: By adjusting the heights of the blocking members at different positions to be the same or different, the plasma concentration distribution in different areas above the confinement ring can be adjusted.

The driving device drives the gas channel adjusting member to move radially, so that the gap of the gas channel becomes larger or smaller. Further, when it is necessary to control the gap of the gas channel to become larger, the driving device drives the gas channel adjusting member to move away from the central diameter of the constraint ring. When the gap that needs to control the gas channel becomes smaller, the driving device drives the gas channel adjustment member to move radially toward the center of the constraint ring (see Figure 5c).

The driving device drives the gas channel adjusting member to move upward, so that the blocking member contacts the restraining ring (see Figure 5d).

In specific applications, the plasma treatment device can perform a pre-etching process on the substrate. After running for a period of time, the substrate is taken out, and the gap of the gas channel of the constraint ring in the corresponding adjustment area of the substrate is adjusted according to the etching condition of the substrate. And in the subsequent etching process, the corresponding etching process is performed according to the set gas channel gap.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as limiting the present invention. Various modifications and alternatives to the present invention will be apparent to those of ordinary skill in the art upon reading the above. Therefore, the protection scope of the present invention should be limited by the appended patent application scope.

1: Plasma treatment device 10:Reaction chamber 11: Upper electrode 12:Gas source 13: Lower electrode 131:Pedestal 14:RF power supply 15: Vacuum pump 16:Constraint ring 160:Adjustment area 161:Gas channel 162: guide ring 1620:Second arc 163:Connecting frame 17: Ground terminal 2: Gas channel adjustment piece 21: blocking piece 210: First arc piece 22:movable frame 23: Support frame A: Process area B: Processing area W: substrate Wa, Wb: substrate area S61, S62, S63: steps

Figure 1 is a schematic structural diagram of a plasma treatment device that does not adopt the present invention; Figure 2 is a schematic structural diagram of a plasma treatment device according to a specific embodiment of the present invention; Figure 3 is a bottom view of the restraint ring of the present invention; Figure 4 is a schematic structural diagram of a constraint ring assembly used in a plasma processing device of the present invention; Figures 5a to 5d are structural schematic diagrams of the gap adjustment method of the gas channel of the present invention; FIG. 6 is a flow chart of the exhaust gas control method of the plasma treatment device of the present invention.

1: Plasma treatment device

10:Reaction chamber

11: Upper electrode

12:Gas source

13: Lower electrode

14:RF power supply

15: Vacuum pump

16:Constraint ring

17: Ground terminal

A: Process area

W: substrate

Claims (14)

A constraint ring assembly for a plasma processing device, the plasma processing device includes a reaction chamber, a base for supporting a substrate is provided in the reaction chamber, wherein the restraint ring assembly is disposed around the periphery of the base and Between the side walls of the reaction chamber, the constraint ring assembly includes: a constraint ring having a plurality of gas channels for discharging gas to the exhaust area below the constraint ring; a plurality of gas channel adjustment members located at Below the constraint ring, each gas channel adjustment member includes a blocking member. Each blocking member independently moves relative to the constraining ring in the vertical direction or along the radial direction of the constraining ring. The gap of the channel is adjusted to divide the entire constraint ring into a plurality of adjustment areas. The confinement ring assembly for a plasma processing device as claimed in claim 1, wherein the plurality of gas channel adjusting members are arranged along the circumferential direction of the confinement ring. The confinement ring assembly for a plasma processing device as claimed in claim 1, wherein when the blocking member moves in the radial direction of the confinement ring, the gap of the gas channel is adjusted; when the blocking member moves in the vertical direction, Adjust the gas resistance of the gas channel. The constraint ring assembly for a plasma processing device as claimed in claim 1, wherein the gas channel adjustment member further includes: a movable frame vertically disposed on the circumferential outside of the constraint ring; a support frame for The blocking member is supported and connected to the movable frame; the movable frame is connected to a driving device and drives the blocking member to move through the supporting frame. The confinement ring assembly for a plasma processing device as described in Claim 1 or Claim 4, wherein the confinement ring includes a plurality of guide rings arranged concentrically, and a plurality of connecting frames connecting the guide rings. , the gas channel is an annular groove shape between adjacent guide rings. channel; the blocking member corresponding to one of the adjustment areas of the constraint ring is distributed in a fan shape, and the blocking member includes a plurality of arc-shaped members corresponding to at least a part of the gas channel in the adjustment area; the arc-shaped member is in the The lower part of the gas channel moves radially, and the range of the arc-shaped member blocking the gas channel is adjusted to adjust the gap of the gas channel. The constraint ring assembly for a plasma processing device as claimed in claim 5, wherein the support frame is disposed correspondingly below the connecting frame; and the movable frame is disposed vertically in the outermost guide ring. The constraint ring assembly for a plasma processing device as described in claim 5, wherein the connecting frames are distributed at intervals along the circumferential direction of the constraint ring, and are each arranged in a radial direction; each of the adjustment areas is related to the adjustment area. The connecting frame is symmetrical. The confinement ring assembly for a plasma processing device as claimed in claim 1, wherein the material of the gas channel adjustment member of the gas channel is the same as or different from the material of the confinement ring. The constraint ring assembly for a plasma processing device as claimed in claim 5, wherein the lengths of the plurality of arc-shaped members of the blocking member decrease sequentially from outside to inside. The constraint ring assembly for a plasma processing device as claimed in claim 9, wherein the length of a first arc-shaped member and the second arc starting from the outer ring of the constraint ring in the adjustment area corresponding to the blocking member The lengths are equal. The constraint ring assembly for a plasma processing device as claimed in claim 4, wherein the driving device includes one of a motor device, a hydraulic device and a pneumatic device. A plasma processing device, which includes: a reaction chamber, a base for supporting a substrate is provided in the reaction chamber; The constraint ring assembly according to any one of claims 1 to 11, the constraint ring assembly is circumferentially disposed between the periphery of the base and the side wall of the reaction chamber. An exhaust control method for a plasma treatment device, which includes the following steps: providing the plasma treatment device as described in claim 12; and when it is necessary to adjust a reaction chamber environment in the plasma treatment device, using a The driving device drives a gas channel adjusting member to move and adjust the gap of a gas channel; by adjusting the gap of the gas channel, the gas flow distribution in the exhaust area corresponding to the lower part of the gas channel adjusting member is adjusted. The exhaust control method of a plasma processing device as claimed in claim 13, wherein the driving device is used to drive the gas channel adjusting member to move, and adjusting the gap of the gas channel includes: the driving device drives the gas channel adjusting member to move downward. , causing a blocking member to separate from a constraint ring; the driving device drives the gas channel adjusting member to move radially, so that the gap of the gas channel becomes larger or smaller; the driving device drives the gas channel adjusting member to move upward, so that the gas channel adjusting member moves upward The blocking member is in contact with the restraining ring.