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

Abstract

The present invention discloses a confinement ring assembly, a plasma processing device and an exhaust control method thereof, wherein the confinement ring assembly comprises: a confinement ring, the confinement ring having a plurality of gas channels for discharging gas to an exhaust area below the confinement ring; a plurality of gas channel adjustment members located below the confinement ring, each of the gas channel adjustment members comprising a blocking member, the blocking member being movable relative to the confinement ring to adjust the gap of the gas channel of the confinement ring, so as to divide the entire confinement ring into a plurality of adjustment areas. The present invention can utilize a microscopic adjustment process to change the gap of the confinement ring gas channel, can adjust the environment of the cavity by region, improve the problem of asymmetry of the process region, and further improve the process uniformity of the substrate.

Description

Technical Field

[0001] The present invention relates to a device in the semiconductor field, and in particular to a confinement ring assembly, a plasma processing device and an exhaust control method thereof. Background Art

[0002] Plasma processing devices utilize the working principle of a vacuum reaction chamber to process semiconductor substrates and plasma flat panels. The working principle of a vacuum reaction chamber is to introduce a reaction gas containing an appropriate etchant or deposition source gas into the vacuum reaction chamber, and then input radio frequency energy into the vacuum reaction chamber to activate the reaction gas, thereby igniting and maintaining plasma, so as to etch a material layer on the substrate surface or deposit a material layer on the substrate surface, thereby processing the semiconductor substrate and the plasma flat panel. For example, a capacitive plasma reactor has been widely used to process semiconductor substrates and display flat panels. In a capacitive plasma reactor, when radio frequency power is applied to one or both of two electrodes, a capacitive discharge is formed between a pair of parallel electrodes.

[0003] Plasma is diffuse, and although most of the plasma will stay in the processing area between a pair of electrodes, part of the plasma may fill the entire working chamber. For example, the plasma may leak into the non-processing area below the vacuum reaction chamber. If the plasma reaches these areas, these areas may then be corroded, deposited, or eroded, which will cause particle contamination inside the reaction chamber, thereby reducing the reusability of the plasma processing device and may shorten the working life of the reaction chamber or reaction chamber components. If the plasma is not confined to a certain working area, the charged particles will hit the unprotected area, resulting in impurities and contamination on the surface of the semiconductor substrate.

[0004] Therefore, the industry generally also sets a confinement ring in the plasma processing device to control the exhaust of the spent reaction gas and electrically neutralize the charged particles in the reaction gas when they pass through the plasma confinement device, thereby basically confining the discharge within the processing area to prevent cavity contamination problems that may be caused during the use of the plasma processing device.

[0005] However, those skilled in the art should understand that the plasma process area within the plasma processing device will produce uneven phenomena, and the unevenness of the process area will further lead to process non-uniformity of the substrate. It is well known that the non-uniformity of the substrate process is a core technical problem that needs to be solved in this field, and the present invention is proposed based on this. Summary of the invention

[0006] The purpose of the present invention is to provide a confinement ring assembly, a plasma processing device and an exhaust control method thereof, which utilizes a micro-adjustment process to change the gap of the confinement ring gas channel, can adjust the environment of the cavity in different regions, improve the problem of asymmetry of the process area, and further improve the process uniformity of the substrate.

[0007] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0008] A confinement ring assembly for a plasma processing device, the plasma processing device comprising a reaction chamber, a pedestal for supporting a substrate is arranged in the reaction chamber, wherein the confinement ring assembly is arranged around the periphery of the pedestal and the side wall of the reaction chamber, and the confinement ring assembly comprises:

[0009] a confinement ring having a plurality of gas passages for discharging gas to an exhaust region below the confinement ring;

[0010] A plurality of gas channel adjustment members are located below the confinement ring, each of which includes a blocking member that can move relative to the confinement ring to adjust the gap of the gas channel of the confinement ring to divide the entire confinement ring into a plurality of adjustment areas.

[0011] Furthermore, a plurality of the gas channel adjustment members are arranged along the circumferential direction of the confinement ring.

[0012] Further, the blocking member can move relative to the confinement ring in a horizontal direction to adjust the gap of the gas channel, and / or the blocking member can move relative to the confinement ring in a vertical direction to adjust the gas resistance of the gas channel.

[0013] Furthermore, the gas channel regulating member further comprises:

[0014] A movable frame is vertically arranged on the circumferential outer side of the restraining ring;

[0015] A support frame, which is used to support the blocking member and is connected to the movable frame;

[0016] The movable frame is connected with the driving device and drives the blocking member to move through the supporting frame.

[0017] Furthermore, the confinement ring comprises a plurality of guide rings arranged concentrically, and a plurality of connecting frames for connecting the guide rings, and the gas channel is an annular groove-shaped channel between adjacent guide rings;

[0018] The blocking member corresponding to an adjustment area 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 of the adjustment area; the arc-shaped member moves radially below the gas channel, and the range of the arc-shaped member blocking the gas channel is adjusted to adjust the gap of the gas channel.

[0019] Furthermore, the support frame is correspondingly arranged below the connecting frame;

[0020] The movable frame is vertically arranged in the outermost guide ring.

[0021] Furthermore, the connecting frames are distributed at intervals along the circumferential direction of the restraint ring and are each arranged in the radial direction; each adjustment area is symmetrical with respect to the connecting frame of the adjustment area.

[0022] Furthermore, the material of the gas channel regulating member is the same as or different from the material of the confinement ring.

[0023] Furthermore, the lengths of the plurality of arc-shaped parts of the blocking member decrease successively from the outside to the inside.

[0024] Furthermore, the length of the first arc-shaped member is equal to the length of a second arc starting from the outer circle of the constraint ring in the adjustment area corresponding to the blocking member.

[0025] Furthermore, the driving device includes one of a motor device, a hydraulic device or a pneumatic device.

[0026] A plasma processing device, characterized in that it comprises:

[0027] A reaction chamber, wherein a base for supporting a substrate is arranged in the reaction chamber;

[0028] The above-mentioned confinement ring assembly is disposed around the periphery of the base and the side wall of the reaction chamber.

[0029] A method for controlling exhaust gas of a plasma processing device, characterized in that it comprises the following steps:

[0030] Providing the above-mentioned plasma processing device; and

[0031] When the reaction chamber environment in the plasma processing device needs to be adjusted, the driving device is used to drive the gas channel adjustment member to move and adjust the gap of the gas channel;

[0032] By adjusting the gap of the gas channel, the gas flow distribution of the exhaust area below the gas channel regulating member is adjusted.

[0033] Further, the driving device is used to drive the gas channel adjustment member to move, and the gap of the gas channel is adjusted, including:

[0034] The driving device drives the gas channel regulating member to move downward, so that the blocking member is separated from the restraining ring;

[0035] The driving device drives the gas channel adjusting member to move radially, so that the gap of the gas channel becomes larger or smaller;

[0036] The driving device drives the gas passage regulating member to move upward so that the blocking member contacts the confinement ring.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] The present invention changes the gap of the confinement ring gas channel through a micro-adjustment process, can adjust the environment of the cavity in different regions, improve the problem of asymmetry of the process regions, and further improve the process uniformity of the substrate.

[0039] The present invention can cooperate with a vacuum pump interface to improve the air extraction efficiency and effectively reduce the impurity particles on the machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic structural diagram of a plasma processing device that does not adopt the present invention;

[0041] Figure 2 It is a structural schematic diagram of a plasma processing device according to a specific embodiment of the present invention;

[0042] Figure 3 A bottom view of the confinement ring of the present invention;

[0043] Figure 4 It is a structural schematic diagram of a confinement ring assembly for a plasma processing device of the present invention;

[0044] Figures 5a to 5d A schematic diagram of the structure of adjusting the gap of the gas channel of the present invention;

[0045] Figure 6 The figure is a flow chart of the exhaust control method of the plasma processing device of the present invention. DETAILED DESCRIPTION

[0046] In order to understand the features, contents and advantages of the present invention and the effects that can be achieved, the present invention is hereby described in detail as follows in conjunction with the accompanying drawings and in the form of an embodiment. The drawings used therein are only for illustration and auxiliary description purposes and may not be the actual proportions and precise configurations after the implementation of the present invention. Therefore, the proportions and configuration relationships of the attached drawings should not be interpreted or limited to the scope of rights of the present invention in actual implementation.

[0047] The inventive mechanism of the present invention is to set a plurality of gas channel adjustment members under the confinement ring, each of the gas channel adjustment members includes a blocking member, and the blocking member can move relative to the confinement ring to adjust the gap of the gas channel of the confinement ring to divide the entire confinement ring into a plurality of adjustment areas. Figure 1 FIG. 4 shows a process area in a plasma processing apparatus before using the present invention. Figure 1 As shown, since the confinement ring is directly or indirectly grounded on the right side of the chamber shown in the figure, the process area A near the grounding point (the left side of the plasma processing device shown in the figure) is "lifted" higher, and the plasma concentration is lower than that on the other side of the chamber without the grounding end (the right side of the plasma processing device shown in the figure). As a result, the process rate of the edge portion of the substrate W to be processed on the grounding end side is reduced, while the process rate on the other side is relatively high, and the substrate W obtained by the process will inevitably have uniformity defects.

[0048] See also Figure 2 , Figure 2The structure diagram of the plasma processing device using the confinement ring assembly of the present invention is shown in the figure. The plasma processing device 1 shown in the figure has a reaction chamber 10, which is basically cylindrical and has a substantially vertical side wall. The reaction chamber 10 has an upper electrode 11 and a lower electrode 13 arranged in parallel with each other. Generally, the area between the upper electrode 11 and the lower electrode 13 is a processing area B, and the area B will form high-frequency energy to ignite and maintain 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 can be a semiconductor substrate to be etched or processed or a glass plate 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 more radio frequency power supplies 14 can be applied to the lower electrode 13 alone or simultaneously and separately to the upper electrode 11 and the lower electrode 13, so as to transmit 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 processing area A between the upper electrode 11 and the lower electrode 13. This electric field accelerates a small amount of electrons present inside the reaction chamber 11, causing them to collide with gas molecules of the input reaction gas. These collisions lead to ionization of the reaction gas and excitation of the plasma, thereby generating plasma in the reaction chamber 10. When subjected to these strong electric fields, the neutral gas molecules of the reaction gas lose electrons, leaving positively charged ions. The positively charged ions are accelerated toward the lower electrode 13, combined with neutral substances in the substrate being processed, and stimulate substrate processing, i.e. etching, deposition, etc. An exhaust area is provided at a suitable position of the plasma processing device 1, and the exhaust area is connected to an external exhaust device (such as a vacuum pump 15) to extract the used reaction gas and byproduct gas from the processing area B during the processing process.

[0049] In an application scenario, due to Figure 1 The confinement ring 16 is connected to the ground terminal 17 near the right chamber of the plasma processing device shown, and the plasma process area A is "lifted up" above the confinement ring 16 on the right. From a spatial perspective, the plasma process area A presents an asymmetric cloud shape. Specifically, near the confinement ring connected to the ground terminal, its process area is "lifted up", and near the confinement ring far away from the ground terminal, its process area extends all the way to the bottom of the substrate. Therefore, the plasma concentration of the substrate area Wa in this area is relatively low. Relatively speaking, the plasma concentration of the corresponding area Wb on the other side of the substrate W in the horizontal direction is relatively high.

[0050] It should be noted that although the restraint ring 16 shown in the figure is directly connected to the ground terminal 17, those skilled in the art should understand that the restraint ring 16 can be selectively connected to the ground terminal 17 indirectly, for example, connected to the ground terminal 17 through a connecting component (not shown).

[0051] Figure 3 FIG. 2 is a bottom view of the confinement ring of the present invention, as shown in FIG. Figure 3 As shown, the above-mentioned confinement ring 16 includes a plurality of guide rings 162 arranged concentrically, and a plurality of connecting frames 163 connecting the guide rings. The gas channel 161 is an annular groove channel between adjacent guide rings, and along the circumferential direction of the confinement ring, the entire confinement ring 16 is virtually divided into a plurality of adjustment areas 160.

[0052] Figure 4 is a schematic diagram of a confinement ring assembly for a plasma processing device, referring to Figure 4 Combined with Figure 2 and Figure 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. The confinement ring assembly includes a confinement ring 16 and a plurality of gas channel adjustment members 2, wherein the confinement ring 16 has a plurality of gas channels 161 for discharging gas to the exhaust area below the confinement ring. The plurality of gas channel adjustment members 2 are located below the confinement ring 16. Specifically, a gas channel adjustment member 2 can be arranged below the adjustment area 160 corresponding to the confinement ring 16. Each of the gas channel adjustment members 2 includes a blocking member 21. The blocking member 21 can move relative to the confinement ring 16 to adjust the gap of the gas channel 161 of the confinement ring so as to divide the entire confinement ring 16 into a plurality of adjustment areas 160.

[0053] It should be noted that the above-mentioned blocking member 21 can divide the entire confinement ring into several adjustment areas in equal proportion, and adjust the plasma concentration environment in the reaction chamber in different areas. For example, when the plasma concentration in the substrate area Wa is low, the blocking member of the gas channel adjustment member 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 in the substrate area Wb is high, the blocking member 21 of the gas channel adjustment member is controlled to move, so that the gap of the gas channel 161 of the confinement ring is increased.

[0054] Furthermore, a plurality of the gas channel adjusting members 2 are arranged along the circumferential direction of the restraining ring, and the blocking member 21 can move relative to the restraining ring 16 in the horizontal direction or the vertical direction to adjust the gap of the gas channel 161 .

[0055] Figures 5a to 5d The schematic diagram of the structure of adjusting the gap of the gas channel of the present invention is as follows: Figure 5a As shown, in a specific embodiment, the gas channel regulating member 2 also includes: a movable frame 22, which is vertically arranged on the circumferential outer side of the restraint ring 16; a support frame 23, which is used to support the blocking member 21 and is connected to the movable frame 22; the movable frame 22 is connected to a driving device (not shown) and drives the blocking member 21 to move through the support frame 23.

[0056] See also Figure 3 and Figure 4 The confinement ring 16 includes a plurality of guide rings 162 arranged concentrically, and a plurality of connecting frames 163 connecting the guide rings. The gas channel 161 is an annular groove channel between adjacent guide rings. The blocking member 21 corresponding to an adjustment area of ​​the confinement ring is distributed in a fan shape. The blocking member 21 includes a plurality of arc-shaped members corresponding to at least a part of the gas channel of the adjustment area. The arc-shaped member moves radially below the gas channel to adjust the range of the gas channel blocked by the arc-shaped member to adjust the gap of the gas channel 161. In this way, by adjusting the gap of the gas channel in each area, the amount of gas flowing through the entire confinement ring 16 is similar.

[0057] It should be noted that the support frame 23 is correspondingly arranged below the connecting frame 163; the movable frame 22 is vertically arranged in the outermost guide ring. The connecting frames 163 are distributed at intervals along the circumferential direction of the constraint ring 16, and are each arranged in the radial direction; each adjustment area is symmetrical about the connecting frame 163 of the adjustment area.

[0058] The material of the gas channel adjustment member 2 is the same as that of the confinement ring 16, which can prevent the byproducts of the cavity reaction from etching the gas channel adjustment member. Furthermore, the material of the confinement ring includes insulating materials such as quartz, alumina or conductive aluminum coated with corrosion-resistant materials, as long as the potential can be guaranteed to be floating.

[0059] Preferably, see Figure 4 The lengths of the arc-shaped parts of the blocking member decrease from the outside to the inside, and the length of the first arc-shaped part 210 is equal to the length of the second arc 1620 starting from the outer circle of the constraint ring in the adjustment area corresponding to the blocking member. This structure can better prevent the blocking members of the two adjacent gas channels 161 adjustment members from contacting and rubbing and being damaged during horizontal movement.

[0060] The driving device comprises one of a motor device, a hydraulic device or a pneumatic device.

[0061] It should be noted that the driving device has mature technical support in the prior art (such as GUI computer control or manual control), which will not be described here for the sake of simplicity.

[0062] The plasma processing device provided in the embodiment of the present invention has the same technical features as the confinement ring assembly provided in the above embodiment, and can therefore solve the same technical problems and achieve the same technical effects.

[0063] See also Figure 6 , which is a flow chart of the exhaust control method of the plasma processing device of the present invention. As shown in the figure, the third embodiment of the present invention provides an exhaust control method of a plasma processing device, comprising the following steps:

[0064] S61. Providing a plasma processing device;

[0065] S62, when it is necessary to adjust the reaction chamber environment in the plasma processing device, use the driving device to drive the gas channel adjustment member to move and adjust the gap of the gas channel;

[0066] S63. Adjust the gas flow distribution in the exhaust area below the gas channel regulating member by adjusting the gap of the gas channel.

[0067] Furthermore, the driving device is used to drive the gas channel adjustment member to move, and the gap of the gas channel is adjusted, which further includes the following steps:

[0068] The driving device drives the gas passage adjustment member to move downward, so that the blocking member is separated from the confinement ring (see Figure 5a , 5b ); By adjusting the vertical distance between the blocking member 21 and the confinement ring, the gas resistance regulating effect of the blocking member on the confinement ring can be achieved, and 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.

[0069] The driving device drives the gas channel regulating member to move radially, so that the gap of the gas channel becomes larger or smaller. Further, when the gap of the gas channel needs to be controlled to become larger, the driving device drives the gas channel regulating member to move radially away from the center of the constraint ring. When the gap of the gas channel needs to be controlled to become smaller, the driving device drives the gas channel regulating member to move radially toward the center of the constraint ring (see Figure 5c ).

[0070] The driving device drives the gas passage adjustment member to move upward so that the blocking member contacts the confinement ring (see Figure 5d ).

[0071] In specific applications, the plasma processing 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 confinement ring corresponding to the adjustment area of ​​the substrate is adjusted according to the etching condition of the substrate. The subsequent etching process will perform the corresponding etching process according to the set gas channel gap.

[0072] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A confinement ring assembly for a plasma processing device, the plasma processing device comprising a reaction chamber, a base for supporting a substrate is arranged in the reaction chamber, characterized in that: The confinement ring assembly is disposed around the periphery of the base and the side wall of the reaction chamber, and the confinement ring assembly includes: a confinement ring having a plurality of gas passages for discharging gas to an exhaust region below the confinement ring; A plurality of gas channel adjustment members, located below the confinement ring, each of the gas channel adjustment members comprising a blocking member, the blocking member being movable relative to the confinement ring to adjust the gap of the gas channel of the confinement ring so as to divide the entire confinement ring into a plurality of adjustment areas; The confinement ring comprises a plurality of guide rings arranged concentrically, and a plurality of connecting frames for connecting the guide rings, and the gas channel is an annular groove-shaped channel between adjacent guide rings; The blocking members corresponding to an adjustment area of ​​the constraint ring are distributed in a fan shape, and the blocking members include a plurality of arc-shaped members corresponding to at least a portion of the annular groove-shaped channel of the adjustment area.

2. The confinement ring assembly for a plasma processing device according to claim 1, wherein: A plurality of the gas channel adjustment members are arranged along the circumference of the confinement ring.

3. The confinement ring assembly for a plasma processing device according to claim 1, wherein: The blocking member can move relative to the confinement ring in a horizontal direction to adjust the gap of the gas channel, and / or the blocking member can move relative to the confinement ring in a vertical direction to adjust the gas resistance of the gas channel.

4. The confinement ring assembly for a plasma processing device according to claim 1, wherein: The gas channel regulating member further comprises: A movable frame is vertically arranged on the circumferential outer side of the restraining ring; A support frame, which is used to support the blocking member and is connected to the movable frame; The movable frame is connected with the driving device and drives the blocking member to move through the supporting frame.

5. The confinement ring assembly for a plasma processing device according to claim 4, wherein: The arc-shaped member moves radially below the gas channel, and the range of the gas channel shielded by the arc-shaped member is adjusted to adjust the gap of the gas channel.

6. The confinement ring assembly for a plasma processing device according to claim 5, wherein: The support frame is correspondingly arranged below the connecting frame; The movable frame is vertically arranged in the outermost guide ring.

7. The confinement ring assembly for a plasma processing device according to claim 1, wherein: The connecting frames are distributed at intervals along the circumferential direction of the restraint ring and are respectively arranged in the radial direction; each adjustment area is symmetrical with respect to the connecting frame of the adjustment area.

8. The confinement ring assembly for a plasma processing device according to claim 1, wherein: The material of the gas channel adjusting member is the same as or different from the material of the confinement ring.

9. The confinement ring assembly for a plasma processing device according to claim 1, wherein: The lengths of the arc-shaped parts of the blocking member decrease from the outside to the inside.

10. The confinement ring assembly for a plasma processing device according to claim 9, wherein: The length of the first arc-shaped member is equal to the length of a second arc starting from the outer circle of the constraint ring in the adjustment area corresponding to the blocking member.

11. The confinement ring assembly for a plasma processing device according to claim 4, wherein: The driving device comprises one of a motor device, a hydraulic device or a pneumatic device.

12. A plasma processing device, characterized in that: include: A reaction chamber, wherein a base for supporting a substrate is arranged in the reaction chamber; The confinement ring assembly as described in any one of claims 1-11, wherein the confinement ring assembly is disposed around the periphery of the base and the side wall of the reaction chamber.

13. An exhaust control method for a plasma processing device, characterized in that: The steps include: Providing a plasma processing apparatus as claimed in claim 12; and When the reaction chamber environment in the plasma processing device needs to be adjusted, the driving device is used to drive the gas channel adjustment member to move and adjust the gap of the gas channel; By adjusting the gap of the gas channel, the gas flow distribution of the exhaust area below the gas channel regulating member is adjusted.

14. The exhaust control method of a plasma processing apparatus according to claim 13, wherein: The gas channel adjusting member is driven to move by a driving device to adjust the gap of the gas channel, including: The driving device drives the gas channel regulating member to move downward, so that the blocking member is separated from the restraining 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 passage regulating member to move upward, so that the blocking member contacts the confinement ring.

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