Wafer cooling device and cooling method

Abstract

The invention discloses a wafer cooling device and a cooling method. The wafer cooling device at least comprises a cooling assembly, a polishing assembly and a carrying table assembly. The polishing assembly is located above the carrying table assembly, the cooling assembly is arranged on one side of the carrying table assembly, and the cooling assembly is not in contact with the polishing assembly and the carrying table assembly; wherein the cooling assembly comprises an air blowing swing rod, the air blowing swing rod is located below the polishing assembly, and the cooling assembly blows air to the polishing assembly through the air blowing swing rod. According to the wafer cooling device and method, the surface of the polishing disc can be cooled online in real time in the polishing process, relevant parameters are adjusted according to the temperature of the surface of the wafer, and the cooling effect is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer processing equipment, and relates to a wafer cooling device and a cooling method used in a polishing process. Background Art

[0002] With the development of the semiconductor industry, during the wafer packaging process, the wafer needs to undergo thinning, polishing and other process flows. During the dry polishing process, the temperature of the wafer surface will gradually increase during the polishing process. When the temperature rises to a certain level, it will cause damage to the wafer surface and affect the processing quality of the wafer. Therefore, a cooling device is needed to ensure that the contact surface temperature of the polishing disk and the wafer remains basically constant to ensure the polishing effect.

[0003] The existing solution cannot monitor the surface temperature of the wafer, the cooling process requires manual participation, and the wafer cannot be cooled in time, which can easily cause damage to the wafer. Summary of the invention

[0004] The present invention aims to provide a wafer cooling device and cooling method used in the polishing process, by cooling the polishing disk surface in real time online during the polishing process, adjusting relevant parameters according to the temperature of the wafer surface, and ensuring the cooling effect.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a wafer cooling device, which comprises at least a cooling component, a polishing component and a stage component; the polishing component is located above the stage component, the cooling component is arranged on one side of the stage component, and the cooling component is not in contact with the polishing component and the stage component;

[0007] Wherein, the cooling assembly comprises an air blowing swing rod, and the air blowing swing rod is located below the polishing assembly, and the cooling assembly blows air to the polishing assembly through the air blowing swing rod.

[0008] In a replaceable embodiment, the cooling assembly also includes a connecting plate, a swing shaft and a swing cylinder, the blowing swing rod is fixed on the connecting plate, the connecting plate is fixedly mounted on the swing shaft, a swing cylinder is arranged under the swing shaft, and the swing cylinder adjusts the blowing position of the blowing swing rod.

[0009] In a replaceable embodiment, the polishing assembly includes a polishing spindle and a polishing disk arranged at one end of the polishing spindle, the carrier assembly includes a wafer carrier and a dressing disk spindle installed on the wafer carrier, the surface of the polishing disk is in contact with the wafer carrier, and the polishing disk does not completely cover the surface of the wafer carrier.

[0010] In a replaceable embodiment, the cooling assembly has two parallel blowing rockers, the blowing rockers are closed at one end away from the connecting plate, and a plurality of air outlet holes are opened on the surface of the blowing rockers, and the axes of the air outlet holes are perpendicular to the polishing disk.

[0011] In an alternative embodiment, the distance between the blowing rocker and the polishing disc is 30-50 mm.

[0012] In an alternative embodiment, the polishing assembly further comprises a temperature sensor, wherein the temperature sensor is disposed at the center of the end of the polishing spindle, the polishing disk has a center hole, and the temperature sensor is coaxial with the center hole.

[0013] In an alternative embodiment, the wafer cooling device further includes a controller, and the controller adjusts the air flow rate output by the blowing swing rod according to the wafer surface temperature detected by the temperature sensor.

[0014] The present invention also provides a cooling method applied to the above wafer cooling device, the cooling method comprising:

[0015] Initialize the wafer cooling device, and the air blowing swing arm of the cooling assembly stops at the waiting position, away from the stage assembly;

[0016] The dry polishing process begins. The polishing disc of the polishing assembly moves. Part of the polishing disc contacts the wafer stage of the stage assembly, and the rest of the disc is suspended outside the wafer stage. The temperature sensor of the polishing assembly obtains the initial temperature of the wafer surface. The air blowing swing arm moves to the working position and outputs the initial air flow.

[0017] The temperature sensor detects the real-time temperature of the wafer surface in real time, and the cooling component adjusts the real-time air flow of the blowing swing rod according to the real-time temperature and the initial temperature;

[0018] After the dry-blow process is completed, the air-blowing swing arm returns to the waiting position.

[0019] In an alternative embodiment, the cooling component adjusts the real-time air flow rate of the blowing swing rod according to the real-time temperature and the initial temperature, further comprising:

[0020] Determine the difference between the real-time temperature and the initial temperature. When the difference is not less than the preset temperature difference, increase the real-time air flow of the blowing swing rod according to the difference.

[0021] TT I >0 and T D ≠0;

[0022] Where, L is the real-time gas flow, L 1 is the initial gas flow rate, L D For each phase difference in temperature T DThe increase in air flow at that time, T is the real-time temperature, T I is the initial temperature, T D The temperature difference for which the air flow needs to be adjusted;

[0023] The real-time air flow rate is determined. When the real-time air flow rate is not less than the final air flow rate, the real-time air flow rate of the blowing rocker 11 is no longer adjusted.

[0024] In an alternative embodiment, the gas output by the blowing rocker 11 is blown upward to the suspended portion of the polishing disc 21 .

[0025] Beneficial effects of the present invention:

[0026] The present invention provides a cooling device and a cooling method, which can cool the surface of the polishing disk online as needed, thereby reducing the contact temperature between the polishing disk and the wafer surface, adjusting the air flow rate according to the actual temperature of the wafer surface, increasing the cooling rate, and improving the processing quality of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a wafer cooling device of the present invention;

[0028] Figure 2 It is a schematic diagram of the structure of the cooling assembly of the present invention;

[0029] Figure 3 It is a schematic diagram of the air outlet structure of the present invention.

[0030] Figure numerals: 10 - cooling component 10, 20 - polishing component, 30 - carrier component, 11 - air blowing rocker, 12 - connecting plate, 13 - swing shaft, 14 - swing cylinder, 15 - air outlet, 21 - polishing disk, 22 - temperature sensor, 31 - wafer carrier. DETAILED DESCRIPTION

[0031] 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.

[0032] 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 of 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 examples of various specific 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.

[0033] like Figure 1-Figure 3 As shown, the present invention provides a wafer cooling device, which at least includes a cooling component 10, a polishing component 20 and a stage component 30.

[0034] The polishing assembly 20 is located above the stage assembly 30. When the dry polishing process is performed, the polishing assembly 20 runs to the stage assembly 30 and partially contacts the stage assembly 30. The cooling assembly 10 is arranged on one side of the stage assembly 30, and the cooling assembly 10 does not contact the polishing assembly 20 and the stage assembly 30.

[0035] Preferably, the cooling assembly 10 is entirely located below the polishing assembly 20 and performs cooling operations for the polishing assembly 20 .

[0036] Specifically, the cooling assembly 10 includes an air blowing swing rod 11, and the air blowing swing rod 11 is located below the polishing assembly 20. The cooling assembly 10 blows air toward the polishing assembly 20 through the air blowing swing rod 11, thereby achieving a cooling effect.

[0037] In addition, the cooling assembly 10 also includes a connecting plate 12, a swing shaft 13 and a swing cylinder 14. The blowing swing rod 11 is fixed on the connecting plate 12, and the connecting plate 12 is fixedly installed on the swing shaft 13. A swing cylinder 14 is arranged under the swing shaft 13, and the swing cylinder 14 adjusts the blowing position of the blowing swing rod 11.

[0038] Furthermore, an air inlet joint is provided at one end of the air blowing rocker 11 fixed to the connecting plate 12, and the cooling gas enters the air blowing rocker 11 from the air inlet joint.

[0039] The polishing assembly 20 includes a polishing spindle (not shown) and a polishing disc 21 disposed at one end of the polishing spindle. Optionally, the polishing disc 21 is sleeved and fixed on the polishing spindle, and the rotation of the spindle drives the rotation of the polishing disc 21.

[0040] The stage assembly 30 includes a wafer stage 31 and a dressing disk spindle (not shown) mounted on the wafer stage 31. The surface of the polishing disk 21 contacts the wafer stage 31, and the polishing disk 21 does not completely cover the surface of the wafer stage 31. Specifically, the wafer to be processed is placed on the wafer stage 31. During the dry polishing process, the lower surface of the polishing disk 21 contacts the surface of the wafer placed on the wafer stage 31. Preferably, the polishing disk 21 only partially contacts the wafer surface, and the portion of the polishing disk 21 that does not contact the wafer is suspended on the wafer stage 31.

[0041] Furthermore, the cooling assembly 10 has two air blowing swing rods 11 arranged in parallel, one end of the air blowing swing rod 11 away from the connecting plate 12 is closed, and a plurality of air outlet holes 15 are provided on the surface of the air blowing swing rod 11, and the axis of the air outlet hole 15 is perpendicular to the polishing disc 21. Optionally, the angle between the axis of the air outlet hole 15 and the surface of the polishing disc 21 can also be adjusted according to the actual cooling effect. The axial direction of the air outlet hole 15 can be changed by rotating the air blowing swing rod 11. Preferably, the air pressure discharged through the air outlet hole 15 is adjusted to 0.4Mpa, and the air pressure can also be adjusted according to the actual effect.

[0042] The cooling gas enters the blowing rocker 11 through the air inlet joint, is discharged through the air outlet 15, and is blown toward the polishing disc 21.

[0043] Preferably, the air outlet holes 15 on the surface of the blowing rocker 11 are arranged in a row at equal intervals, the number of the air outlet holes 15 on each blowing rocker 11 is between 20 and 24, and the diameter of each air outlet hole 15 is about 1.5 mm.

[0044] In order to ensure the cooling effect, there is a certain distance between the air blowing rocker 11 and the polishing disk 21. Preferably, the distance between the air blowing rocker 11 and the polishing disk 21 is 30-50 mm.

[0045] The polishing assembly 20 further includes a temperature sensor 22, which is disposed at the center of the end of the polishing spindle. The polishing plate 21 has a center hole, and the temperature sensor 22 is coaxial with the center hole. During the dry polishing process, the temperature sensor 22 monitors the temperature of the surface of the collection wafer through the center hole.

[0046] As another embodiment, the wafer cooling device of the present invention further includes a controller (not shown), which adjusts the air flow output by the blowing swing rod 11 according to the wafer surface temperature detected by the temperature sensor 22 .

[0047] Specifically, the controller collects the initial temperature of the wafer surface and the real-time temperature of the wafer surface detected by the temperature sensor 22, calculates the difference between the initial temperature and the real-time temperature in real time, determines the value of the temperature difference, and adjusts the air flow of the blowing rocker 11 according to the determination result.

[0048] That is, when TT I >0 and T D ≠0,

[0049]

[0050] in, Indicates rounding down, L is the real-time gas flow, L 1 is the initial gas flow rate, L D For each phase difference in temperature T D The increase in air flow at that time, T is the real-time temperature, T I is the initial temperature, T D The temperature difference that requires adjustment of the air flow rate.

[0051] When L ≥ L 2 When, L 2 is the final air flow, that is, the real-time air flow L is greater than or equal to the final air flow L 2 At this time, the air flow rate output by the blowing swing rod 11 is no longer adjusted, that is, the air flow rate has reached the critical value and the cooling effect is optimal.

[0052] The present invention also provides a cooling method for protecting the wafer cooling device, the cooling method comprising: initializing the wafer cooling device, the blowing swing rod 11 of the cooling component 10 stops at a waiting position, away from the carrier component 30.

[0053] Specifically, the swing of the blowing swing rod 11 is controlled by the swing cylinder 14 .

[0054] Preferably, the blowing swing rod 11 has two positions, namely a waiting position and a working position, wherein the waiting position is a position away from the wafer stage 31, and the working position is a position close to the wafer stage 31. Before the dry polishing process begins, the blowing swing rod 11 is adjusted to the waiting position by the swing cylinder 14.

[0055] The dry polishing process starts, the polishing disk 21 of the polishing assembly 20 moves, a portion of the polishing disk 21 contacts the wafer stage 31 of the stage assembly 30, and the rest of the portion is suspended outside the wafer stage 31, the temperature sensor 22 of the polishing assembly 20 obtains the initial temperature of the wafer surface, the blowing rocker 11 moves to the working position, and outputs the initial air flow.

[0056] Specifically, after the dry polishing process starts, when the polishing disc 21 contacts the wafer on the wafer carrier 31, it will not completely cover the wafer on the wafer carrier 31, and a part of the polishing disc 21 is suspended outside the wafer carrier 31. At this time, the blowing swing rod 11 is adjusted to the working position by the swing cylinder 14, and the air valve for delivering cooling gas is opened. The cooling gas enters the blowing swing rod 11 through the air inlet joint, and is then discharged through the air outlet 15 and blown to the polishing disc 21. At this time, the air flow rate delivered is the initial air flow rate L 1 At the same time, the temperature sensor 22 detects the initial temperature T of the wafer surface. I And record.

[0057] Optionally, the gas output by the blowing swing rod 11 is blown upward to the suspended part of the polishing plate 21. That is, the cooling gas is discharged upward through the gas outlet 15 and blown to the suspended part of the polishing plate 21.

[0058] The temperature sensor 22 detects the real-time temperature of the wafer surface in real time, and the cooling component 10 adjusts the real-time air flow of the blowing swing rod 11 according to the real-time temperature and the initial temperature;

[0059] Specifically, during the polishing process, the temperature sensor 22 detects the real-time temperature T of the wafer surface in real time. I The difference is greater than or equal to the preset temperature difference T that needs to adjust the air flow D When the gas flow rate L is increased D , when the real-time air flow L is greater than or equal to the final air flow L 2 When the temperature difference T is reached, the gas flow rate will not increase until the dry polishing process of the wafer is completed. D Increase in air flow rate L D The temperature difference T that needs to adjust the air flow D It is a fixed value that can be set and adjusted according to actual conditions. It is an empirical value obtained through a large number of experiments based on changes in wafer size.

[0060] Furthermore, the cooling component 10 is based on the real-time temperature T and the initial temperature T I , adjusting the real-time air flow L of the blowing swing rod 11 includes:

[0061] Determine the real-time temperature T and the initial temperature T I When the difference is not less than the preset temperature difference L for adjusting the air flow rate D When the real-time air flow rate L of the blowing rocker 11 is increased according to the difference, the adjustment formula is:

[0062] TT I >0 and T D ≠0;

[0063] Where, L is the real-time gas flow, L1 is the initial gas flow rate, L D For each phase difference in temperature T D The increase in air flow at that time, T is the real-time temperature, T I is the initial temperature, T D The temperature difference for which the air flow needs to be adjusted;

[0064] Determine the real-time air flow L. When the real-time air flow L is not less than the final air flow L 2 , the real-time air flow rate L of the blowing rocker 11 is no longer adjusted.

[0065] After the dry-blow process is completed, the air-blowing swing rod 11 returns to the waiting position.

[0066] The wafer cooling device and cooling method of the present invention can cool the surface of the polishing disk online as needed, thereby reducing the contact temperature between the polishing disk and the wafer surface, and adjust the air flow rate according to the actual temperature of the wafer surface, thereby increasing the cooling rate and improving the processing quality of the wafer.

[0067] 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.

[0068] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A wafer cooling device, characterized in that: The wafer cooling device comprises at least a cooling component (10), a polishing component (20) and a stage component (30); the polishing component (20) is located above the stage component (30), the cooling component (10) is arranged on one side of the stage component (30), and the cooling component (10) is not in contact with either the polishing component (20) or the stage component (30); The cooling assembly (10) comprises an air blowing swing rod (11), the air blowing swing rod (11) is located below the polishing assembly (20), and the cooling assembly (10) blows air toward the polishing assembly (20) via the air blowing swing rod (11).

2. The wafer cooling device according to claim 1, characterized in that: The cooling assembly (10) further comprises a connecting plate (12), a swing shaft (13) and a swing cylinder (14); the blowing swing rod (11) is fixed on the connecting plate (12); the connecting plate (12) is fixedly mounted on the swing shaft (13); a swing cylinder (14) is arranged below the swing shaft (13); and the swing cylinder (14) adjusts the blowing position of the blowing swing rod (11).

3. The wafer cooling device according to claim 1, characterized in that: The polishing assembly (20) comprises a polishing spindle and a polishing disc (21) arranged at one end of the polishing spindle, and the carrier assembly (30) comprises a wafer carrier (31) and a dressing disc spindle mounted on the wafer carrier (31), the surface of the polishing disc (21) is in contact with the wafer carrier (31), and the polishing disc (21) does not completely cover the surface of the wafer carrier (31).

4. The wafer cooling device according to claim 1, characterized in that: The cooling assembly (10) comprises two air blowing swing rods (11) arranged in parallel, one end of the air blowing swing rod (11) away from the connecting plate (12) is closed, a plurality of air outlet holes (15) are provided on the surface of the air blowing swing rod (11), and the axis of the air outlet hole (15) is perpendicular to the polishing disc (21).

5. The wafer cooling device according to claim 3, characterized in that: The distance between the blowing rocker (11) and the polishing disc (21) is 30-50 mm.

6. The wafer cooling device according to claim 3, characterized in that: The polishing assembly (20) further comprises a temperature sensor (22), wherein the temperature sensor (22) is arranged at the center of the end of the polishing spindle, the polishing disc (21) has a center hole, and the temperature sensor (22) is coaxial with the center hole.

7. The wafer cooling device according to claim 6, characterized in that: The wafer cooling device also includes a controller, which adjusts the air flow rate output by the blowing swing rod (11) according to the wafer surface temperature detected by the temperature sensor (22).

8. A cooling method using the wafer cooling device according to any one of claims 1 to 7, characterized in that: The cooling method comprises: Initializing the wafer cooling device, the air blowing swing rod (11) of the cooling component (10) stops at a waiting position and moves away from the stage component (30); The dry polishing process begins, the polishing disc (21) of the polishing assembly (20) moves, a portion of the polishing disc (21) contacts the wafer carrier (31) of the carrier assembly (30), and the remaining portion is suspended outside the wafer carrier (31), the temperature sensor (22) of the polishing assembly (20) obtains the initial temperature of the wafer surface, the air blowing swing rod (11) moves to the working position, and outputs the initial air flow rate; The temperature sensor (22) detects the real-time temperature of the wafer surface in real time, and the cooling component (10) adjusts the real-time air flow rate of the blowing swing rod (11) according to the real-time temperature and the initial temperature; After the dry-buffing process is completed, the air-blowing swing rod (11) returns to the waiting position.

9. The cooling method according to claim 8, characterized in that: The cooling component (10) adjusts the real-time air flow rate of the blowing swing rod (11) according to the real-time temperature and the initial temperature, and further comprises: The difference between the real-time temperature and the initial temperature is determined. When the difference is not less than the preset temperature difference, the real-time air flow rate of the blowing swing rod (11) is increased according to the difference. Among them, L is the real-time air flow, L1 is the initial air flow, and L D For each phase difference in temperature T D The increase in air flow at that time, T is the real-time temperature, T I is the initial temperature, T D The temperature difference for which the air flow needs to be adjusted; The real-time air flow rate is determined. When the real-time air flow rate is not less than the final air flow rate, the real-time air flow rate of the blowing rocker (11) is no longer adjusted.

10. The cooling method according to claim 8, characterized in that: The gas output by the blowing rocker (11) is blown upward to the suspended part of the polishing plate (21).

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