Wafer substrate chemical mechanical grinding processing device and processing method

Abstract

The invention discloses a wafer substrate chemical mechanical grinding machining device and method, the machining device comprises a wafer workbench and a grinding workbench correspondingly arranged above the wafer workbench, a to-be-machined substrate is placed on the wafer workbench, and a grinding disc is further arranged on the grinding workbench; wherein the wafer workbench is provided with a plurality of airflow control holes and chuck pins; the air flow control holes are formed in the wafer workbench at intervals, and the substrate to be machined is fixed to the wafer workbench through the air flow control holes and the chuck pins. According to the processing device disclosed by the invention, a novel substrate processing equipment framework compatible with various sizes and morphologies is established, so that the processing efficiency of the equipment is improved.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor wafer substrate processing equipment, and in particular to a wafer substrate chemical mechanical polishing processing device and a processing method. Background Art

[0002] With the continuous development of third-generation semiconductors represented by silicon carbide (SiC), device products based on SiC substrates are showing a booming development trend. However, due to the limitations of silicon carbide crystal column preparation, the size and shape of silicon carbide substrates have been hovering around traditional circular substrates of 4 inches to 8 inches. The number of bare chips (Die) that can be produced from a single substrate during device processing is directly proportional to the processable size of the substrate. Taking the traditional round substrate as an example, the larger the wafer size, the greater the effective output of bare chips. Therefore, in addition to traditional specifications and sizes, such as round 4-inch, 6-inch, and 8-inch SiC substrates, the demand for substrates to expand to more than 8 inches and non-round has begun to rise. See Table 1 for details.

[0003] Table 1

[0004] Traditional chemical mechanical polishing (CMP) has great limitations in substrate processing due to the influence of the grinding head size and equipment layout. Substrates of different specifications cannot be compatible on the same equipment. The processing process is generally as follows: the grinding head adsorbs the substrate to be processed onto the silicone pad through indirect vacuum, the grinding head moves to the grinding pad, the grinding head drops to the grinding pad, the silicone pad presses the pressure-dropped substrate onto the grinding pad, and then the substrate is subjected to surface grinding by high-speed rotation and dripping of grinding liquid at the same time.

[0005] Therefore, when SiC substrates are processed using traditional chemical mechanical polishing equipment, the following problems exist: 1) Grinding head size limitation Traditional CMP grinding heads are divided into 6-inch, 8-inch, 12-inch and other specifications according to the perfect circle, and it is not possible to process substrates of different sizes on the same grinding head. Under normal circumstances, ordinary equipment cannot switch, and a small number of equipment can switch the processing size by replacing parts such as the grinding head.

[0006] 2) Grinding fluid supply When the substrate is being ground on the grinding disc, the grinding liquid is supplied in a dripping manner. Affected by factors such as high-speed rotation centrifugal force and grinding head pressure, the actual use efficiency of the grinding liquid is greatly reduced. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a wafer substrate chemical mechanical polishing processing device and processing method. The present invention aims at the limitations of traditional CMP equipment architecture when processing SiC substrates, and aims to build a new substrate processing equipment architecture that is compatible with various sizes, specifications, and morphologies, and can efficiently utilize polishing fluid, thereby improving the compatibility, economy and processing efficiency of the equipment.

[0008] In order to achieve the above object, the present invention provides the following technical solutions: A chemical mechanical grinding processing device for wafer substrates, the processing device comprises a wafer worktable and a grinding worktable correspondingly arranged above the wafer worktable, the substrate to be processed is placed on the wafer worktable, and the grinding worktable is also arranged with a grinding disc; Among them, the wafer workbench is provided with a plurality of airflow control holes and chuck pins; the airflow control holes are arranged at intervals on the wafer workbench, and the substrate to be processed is fixed on the wafer workbench through the airflow control holes and the chuck pins.

[0009] As an alternative embodiment, the processing device further includes an air pressure control module, and the air flow control hole adsorbs the substrate to be processed through the air pressure control module.

[0010] As an alternative embodiment, the air pressure control module includes a pressure unit and a vacuum unit; The pressure unit comprises a first locking solenoid valve and a pressure check valve, and the pressure check valve is connected to a pressure source; The vacuum unit comprises a second locking solenoid valve and a gas-liquid separation valve, and the gas-liquid separation valve is connected with the liquid discharge end and the vacuum source.

[0011] As an alternative embodiment, the wafer workbench adopts a circular structure and is divided into four areas in a centrally symmetrical manner, and the airflow control holes are evenly distributed in each area.

[0012] As a replaceable embodiment, four chuck pins are arranged on the wafer worktable, one chuck pin is arranged between two adjacent areas, and the four chuck pins can move toward the center of the wafer worktable at the same time.

[0013] As an alternative embodiment, the grinding workbench is further provided with a plurality of through grinding liquid holes, and the grinding disc arranged on the grinding workbench covers all the grinding liquid holes.

[0014] As an alternative embodiment, a plurality of the grinding liquid holes are distributed along a straight line on the grinding workbench.

[0015] The present invention also provides a processing method using a wafer substrate chemical mechanical polishing processing device, the processing method comprising: Placing the substrate to be processed on the surface of the wafer table; Fixing the substrate to be processed; The grinding table moves downward, and the grinding disk is in adaptive contact with the substrate to be processed; The substrate to be processed is ground, and after the grinding is completed, the substrate to be processed is released.

[0016] As an alternative embodiment, the step of fixing the substrate to be processed further comprises: The vacuum unit of the air pressure control module works, and the substrate to be processed is vacuum-adsorbed on the wafer workbench through the air flow control hole, completing the first positioning and fixing; The chuck pins are closed toward the center of the wafer worktable until the substrate to be processed is clamped and fixed, completing the second positioning and fixing; The step of releasing the substrate to be processed further comprises: The chuck pin is unlocked and moves toward the edge of the wafer table to complete the first release; The pressure unit of the air pressure control module works to blow air toward the substrate to be processed through the air flow control hole to release the vacuum adsorption and complete the second release.

[0017] As an alternative embodiment, the substrate to be processed is ground while the grinding liquid is injected into the grinding disk of the grinding workbench through the grinding liquid hole.

[0018] Beneficial effects of the present invention: The above-mentioned wafer substrate chemical mechanical polishing processing device and processing method provided by the present invention are aimed at the shortcomings of the prior art and the limitations of the traditional CMP equipment architecture when processing SiC substrates. A new equipment architecture is newly constructed that is compatible with substrates of different specifications and efficiently utilizes polishing liquid, thereby improving the compatibility and economy of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a structural schematic diagram of the processing device of the present invention; Figure 2 It is a structural schematic diagram of a wafer workbench of the present invention; Figure 3 This is a schematic structural diagram of a wafer workbench after placing a substrate to be processed in the present invention; Figure 4 It is a schematic diagram of the structure of the wafer workbench of the present invention; Figure 5 It is a structural schematic diagram of the air pressure control module of the present invention; Figure 6 It is a schematic structural diagram of the grinding workbench of the present invention.

[0019] Reference numerals: 1-wafer workbench; 2-grinding workbench; 3-substrate to be processed; 4-grinding disc; 5-air flow control hole; 6-chuck pin; 7-grinding liquid hole; 11-first locking solenoid valve; 12-pressure one-way valve; 13-second locking solenoid valve; 14-gas-liquid separation valve; 15-pressure source; 16-liquid discharge end; 17-vacuum source. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of this application clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] Embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The terms "first", "second", "third", etc. (if any) in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects described in this way can be interchanged where appropriate. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. The directional terms mentioned in the present invention, such as: up, down, left, right, front, back, inside, outside, side, etc., are only reference directions to the accompanying drawings. The embodiments described below by reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention. In addition, the present invention repeats reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but a person of ordinary skill in the art can recognize the application of other processes and / or the use of other materials.

[0022] The present invention provides a wafer substrate chemical mechanical grinding processing device, such as Figure 1-Figure 4 As shown, the processing device includes a wafer worktable 1 and a grinding worktable 2 correspondingly arranged above the wafer worktable 1 , a substrate 3 to be processed is placed on the wafer worktable 1 , and a grinding disc 4 is also arranged on the grinding worktable 2 .

[0023] A plurality of airflow control holes 5 and chuck pins 6 are provided on the wafer worktable 1 . The airflow control holes 5 are arranged at intervals on the wafer worktable 1 . The substrate 3 to be processed is fixed on the wafer worktable 1 through the airflow control holes 5 and the chuck pins 6 .

[0024] Preferably, the processing device further comprises an air pressure control module, and the air flow control holes 5 are adsorbed onto the substrate 3 to be processed through the air pressure control module.

[0025] Specifically, the air pressure control module is disposed below the air flow control hole 5 and is in communication with all the air flow control holes 5 on the wafer workbench 1 , and controls the adsorption and release of all the air flow control holes 5 at the same time.

[0026] Specifically, the air pressure control module includes a pressure unit and a vacuum unit. The pressure unit includes a first locking solenoid valve 11 and a pressure check valve 12, and the pressure check valve 12 is connected to a pressure source 15. The pressure unit is used to inject gas into the airflow control hole 5 on the wafer workbench 1 to release the vacuum adsorption state of the substrate 3 to be processed.

[0027] When the vacuum adsorption state needs to be released, the first locking solenoid valve 11 is opened, the second locking solenoid valve 13 remains closed, and the pressure source 15 injects gas into the airflow control hole 5. After the gas passes through the pressure one-way valve 12 and the first locking solenoid valve 11 in turn, the vacuum adsorption state is released.

[0028] The vacuum unit includes a second locking solenoid valve 13 and a gas-liquid separation valve 14, and the gas-liquid separation valve 14 is connected to the liquid discharge terminal 16 and the vacuum source 17. The vacuum unit is used to evacuate the airflow control hole 5 on the wafer workbench 1, so as to adsorb the substrate 3 to be processed on the wafer workbench 1 and maintain the vacuum adsorption state of the substrate 3 to be processed.

[0029] When it is necessary to maintain the vacuum adsorption state, the first locking solenoid valve 11 remains closed, the second locking solenoid valve 13 is opened, and the vacuum source 17 extracts gas to the airflow control hole 5, and the gas passes through the second locking solenoid valve 13 and the gas-liquid separation valve 14 in sequence and then is discharged to maintain the vacuum adsorption state. If the extracted gas contains liquid, the liquid passes through the gas-liquid separation valve 14 and then is discharged to the liquid discharge end 16.

[0030] Specifically, the wafer workbench 1 is based on a circular grinding disc, and the wafer workbench 1 adopts a circular structure, which is divided into four areas in a centrally symmetrical manner, and the airflow control holes 5 are evenly distributed in each area. Among them, the airflow control holes 5 are arranged with a certain size and interval to provide vacuum and pressure.

[0031] Four chuck pins 6 are arranged on the wafer table 1. Preferably, one chuck pin 6 is arranged between two adjacent areas, and the four chuck pins 6 can move toward the center of the wafer table 1 at the same time. The four chuck pins 6 are arranged near the periphery of the wafer table 1.

[0032] Based on this, the wafer workbench 1 can provide positive and negative pressure through the air flow holes and the chuck pins can clamp and fix the substrate 3 to be processed.

[0033] According to the present invention, the grinding workbench 2 is further provided with a plurality of through grinding liquid holes 7 . Specifically, the grinding disc 4 arranged on the grinding workbench 2 covers all the grinding liquid holes 7 .

[0034] Preferably, a plurality of grinding liquid holes 7 are distributed along a straight line on the grinding workbench 2 , and the length of the arranged grinding liquid holes 7 is not greater than the diameter of the grinding disc 4 .

[0035] The present invention arranges the grinding liquid hole 7 on the grinding workbench 2, so as to cooperate with the grinding disc 4 to continuously supply the grinding liquid during the grinding process.

[0036] When the processing device is working, the wafer worktable 1 is fixed, and the contact between the substrate 3 to be processed and the grinding disc 4 is achieved through the up and down movement of the grinding worktable 2.

[0037] The above-mentioned wafer substrate chemical mechanical polishing processing device provided by the present invention aims at the limitations of the traditional chemical mechanical polishing equipment architecture when processing silicon carbide substrates, and restructures a new equipment that is compatible with substrates of different specifications and efficiently utilizes polishing liquid, thereby improving the compatibility and economy of the equipment, thereby improving the processing efficiency of the equipment.

[0038] The present invention also provides a processing method using a wafer substrate chemical mechanical polishing processing device, the processing method comprising: Placing a substrate 3 to be processed on the surface of a wafer workbench 1; Fixing a substrate 3 to be processed; The step of fixing the substrate 3 to be processed further comprises: The vacuum unit of the air pressure control module works, and the substrate 3 to be processed is vacuum-adsorbed on the wafer workbench 1 through the air flow control hole 5, completing the first positioning and fixing.

[0039] The chuck pins 6 are closed toward the center of the wafer worktable 1 until the substrate 3 to be processed is clamped and fixed, thus completing the second positioning and fixing.

[0040] The grinding table 2 moves downward, and the grinding disk 4 adaptively contacts the substrate 3 to be processed.

[0041] The grinding workbench 2 drives the grinding disc 4 to be pressed downward as a whole until it contacts the surface of the substrate 3 to be processed, and automatically adjusts the contact surface according to the pressure.

[0042] The substrate 3 to be processed is ground, and after the grinding is completed, the substrate 3 to be processed is released.

[0043] While grinding the substrate 3 to be processed, grinding liquid is injected into the grinding disc 4 of the grinding table 2 through the grinding liquid hole.

[0044] The step of releasing the substrate 3 to be processed further comprises: The chuck pin 6 is unlocked and moves toward the edge of the wafer table 1 to complete the first release.

[0045] The pressure unit of the air pressure control module works to blow air toward the substrate 3 to be processed through the air flow control hole 5 to release the vacuum adsorption and complete the second release.

[0046] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A wafer substrate chemical mechanical polishing device, characterized in that: The processing device comprises a wafer worktable (1) and a grinding worktable (2) correspondingly arranged above the wafer worktable (1); a substrate (3) to be processed is placed on the wafer worktable (1); and a grinding disc (4) is also arranged on the grinding worktable (2); The wafer workbench (1) is provided with a plurality of airflow control holes (5) and chuck pins (6); the plurality of airflow control holes (5) are arranged at intervals on the wafer workbench (1), and the substrate (3) to be processed is fixed on the wafer workbench (1) via the airflow control holes (5) and the chuck pins (6).

2. The wafer substrate chemical mechanical polishing device according to claim 1, characterized in that: The processing device further comprises an air pressure control module, and the air flow control hole (5) adsorbs the substrate (3) to be processed through the air pressure control module.

3. The wafer substrate chemical mechanical polishing device according to claim 2, characterized in that: The air pressure control module includes a pressure unit and a vacuum unit; The pressure unit comprises a first locking solenoid valve (11) and a pressure check valve (12), wherein the pressure check valve (12) is connected to a pressure source (15); The vacuum unit comprises a second locking solenoid valve (13) and a gas-liquid separation valve (14), wherein the gas-liquid separation valve (14) is connected to a liquid discharge end (16) and a vacuum source (17).

4. The wafer substrate chemical mechanical polishing device according to claim 1, characterized in that: The wafer workbench (1) adopts a circular structure and is divided into four areas in a centrally symmetrical manner, and the airflow control holes (5) are evenly distributed in each area.

5. The wafer substrate chemical mechanical polishing device according to claim 4, characterized in that: Four chuck pins (6) are arranged on the wafer workbench (1), one chuck pin (6) is arranged between two adjacent areas, and the four chuck pins (6) can move towards the center of the wafer workbench (1) at the same time.

6. The wafer substrate chemical mechanical polishing device according to claim 5, characterized in that: The grinding workbench (2) is also provided with a plurality of through grinding liquid holes (7), and the grinding disc (4) arranged on the grinding workbench (2) covers all the grinding liquid holes (7).

7. The wafer substrate chemical mechanical polishing device according to claim 6, characterized in that: The plurality of grinding liquid holes (7) are distributed along a straight line on the grinding workbench (2).

8. A processing method using the wafer substrate chemical mechanical polishing processing device according to any one of claims 2 to 7, characterized in that: The processing method comprises the following steps: Placing a substrate (3) to be processed on the surface of a wafer workbench (1); Fixing the substrate to be processed (3); The grinding table (2) moves downward, and the grinding disc (4) adaptively contacts the substrate to be processed (3); The substrate to be processed (3) is ground, and after the grinding is completed, the substrate to be processed (3) is released.

9. The processing method according to claim 8, characterized in that: The step of fixing the substrate to be processed (3) further comprises: The vacuum unit of the air pressure control module is in operation, and the substrate to be processed (3) is vacuum-adsorbed on the wafer workbench (1) through the air flow control hole (5), thereby completing the first positioning and fixation; The chuck pins (6) are closed toward the center of the wafer workbench (1) until the substrate (3) to be processed is clamped and fixed, thereby completing the second positioning and fixing; The releasing the substrate to be processed (3) further comprises: The chuck pin (6) is unlocked and moves toward the edge of the wafer workbench (1), completing the first release; The pressure unit of the air pressure control module works to blow air toward the substrate to be processed (3) through the air flow control hole (5), thereby releasing the vacuum adsorption and completing the second release.

10. The processing method according to claim 9, characterized in that: The substrate to be processed (3) is ground, and at the same time, grinding liquid is injected into the grinding disc (4) of the grinding workbench (2) through the grinding liquid hole (7).

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