A method for bonding 8-inch semiconductor ingots

Abstract

A kind of bonding method suitable for 8 inch semiconductor crystal bar, S1, using crystal orientation equipment according to the deviation of crystal orientation to determine the angle α and β that 8 inch crystal bar needs to be deflected for bonding, then 8 inch crystal bar is rotated around its axis to make its Notch rotate β angle, and it is horizontally placed on the stick bar device;S2, the crystal holder with resin plate is placed on the stick bar device, and after rotating the crystal holder to make its rotation angle α, it is fixed on the stick bar device;S3, raise the crystal holder to make the crystal bar and the arc top surface of resin plate fit and compress tightly, until the glue between resin plate and crystal bar is initially cured;S4, take out the initially cured crystal bar to recheck, if the crystal bar bonding is qualified, continue to cure the glue of crystal bar and resin plate until bonding is completed, otherwise, adjust the deflection angle of crystal bar and crystal holder until the crystal bar bonding is qualified;In S4, the crystal bar crystal orientation rechecking instrument is used to detect the initially cured crystal bar to obtain Z, calculate to obtain the actual horizontal crystal orientation X of crystal bar 实 And actual vertical crystal orientation Y 实 , improve accuracy.

Description

Technical Field

[0001] This invention relates to the field of monocrystalline silicon wafer production technology, specifically a bonding method suitable for 8-inch semiconductor ingots. Background Technology

[0002] Ingot bonding is the first step in processing ingots into silicon wafers. An ingot bonding device is used to bond the ingot, resin plate, and ingot together, facilitating subsequent wire cutting. Specifically, the bonding is performed according to the crystal orientation specifications of the semiconductor silicon wafer, ensuring that the wire-cut wafers meet the requirements. Currently, ingot bonding is mostly done manually. First, the required crystal orientation deviation and the crystal orientation equipment are used to calculate the rotation angles α and β needed for ingot bonding. The crystal orientation specifications refer to the angles required for the horizontal and vertical crystal orientations, α is the angle between the ingot and the ingot holder, and β is the angle of rotation of the ingot notch around its axis. Then, the ingot is bonded by rotating it according to α and β. After bonding, the crystal orientation of the ingot needs to be re-inspected to ensure the accuracy of the bonding and thus ensure that the processed semiconductor silicon wafers meet the requirements.

[0003] In the manual bonding method, the crystal orientation of the crystal rod is re-inspected using a crystal orientation re-inspector. Specifically, the crystal orientation re-inspector detects the horizontal and vertical crystal orientations of the bonded crystal rod. However, current crystal orientation re-inspectors can only meet the measurement requirements when β = 0° or ±90°. When the β angle is distributed at any other angle between -90° and 90° (i.e., the crystal orientation deviation requirement is 0.25°, 1.5°, 2.5°, 3°, etc.), the measured value is a composite value of the vertical and horizontal crystal orientations. This composite value has no reference value and cannot guarantee the processing of silicon wafers of this specification. Summary of the Invention

[0004] To address the problem in existing technologies that cannot accurately obtain the horizontal and vertical crystal orientations of the bonded crystal rod, this invention provides a bonding method suitable for 8-inch semiconductor crystal rods, which can obtain accurate horizontal and vertical crystal orientations of the crystal rod, thereby improving the processing precision of 8-inch semiconductor crystal rods.

[0005] To achieve the above objectives, the specific solution adopted by the present invention is as follows: S1, using a crystal orientation device to determine the angles α and β that need to be deflected for bonding an 8-inch crystal rod based on the crystal orientation deviation, then rotating the 8-inch crystal rod around its axis to make its Notch rotate by an angle β, and placing it horizontally on the bonding device;

[0006] S2. Place the crystal holder with the resin plate on the adhesive rod device, rotate the crystal holder to a rotation angle of α, and then fix it on the adhesive rod device.

[0007] S3. Raise the crystal holder to make the crystal rod and the arc-shaped top surface of the resin plate fit together and press tightly until the glue between the resin plate and the crystal rod is initially cured.

[0008] S4. Take out the pre-cured crystal rod for re-inspection. If the crystal rod is bonded properly, continue to cure the glue between the crystal rod and the resin board until the bonding is complete. Otherwise, adjust the deflection angle of the crystal rod and the crystal holder until the crystal rod is bonded properly.

[0009] In S4, the Z-axis of the pre-cured crystal rod is obtained by using a crystal rod orientation re-inspection instrument, and the actual horizontal crystal orientation X of the crystal rod is calculated. 实 and the actual perpendicular crystal orientation Y 实 :

[0010] X 实 =Z×cosβ

[0011] Y 实 = Z × cos(90° - |β|)

[0012] X 实 and Y 实 Compared with the degree of crystal orientation deviation, if X 实 and Y 实 If the crystal rod is bonded to the same degree as the crystal orientation deviation, then the bonding is qualified; otherwise, adjust the deflection angle of the crystal rod and the crystal holder until the bonding is qualified.

[0013] As an optimized solution to the above-mentioned bonding method for 8-inch semiconductor ingots: S1 includes:

[0014] The S11, 8-inch crystal rod is placed horizontally on the crystal orientation equipment, with one end face of the crystal rod facing the X-ray emission tube and receiving tube of the crystal orientation equipment;

[0015] S12, Notch is vertically upward, the crystal rod is rotated around the center point of the above end face until the crystal orientation device shows the maximum reflection intensity, at which point the movement angle of the crystal rod is α;

[0016] S13. Rotate the crystal rod 90° clockwise along the central axis. Rotate the crystal rod around the center point of the above end face until the crystal orientation device shows the maximum reflection intensity. At this time, the movement angle of the crystal rod is β.

[0017] S14. The crystal rod is rotated by an angle β around its axis with Notch facing upwards and placed horizontally on the sticking device.

[0018] As an alternative optimization of the bonding method applicable to 8-inch semiconductor ingots described above: in step S2, adhesive is applied to the bottom and top surfaces of the resin plate, and the bottom surface of the resin plate is bonded to the top surface of the crystal holder.

[0019] As an optimization of the above-mentioned bonding method for 8-inch semiconductor ingots: S3 includes,

[0020] S31. Raise the crystal holder so that the circumferential surface of the crystal rod is in contact with and pressed tightly against the arc-shaped top surface of the resin plate.

[0021] S32. When the pressure between the resin plate and the crystal rod reaches 70-90 kg, the crystal holder stops moving.

[0022] S33. Under the above pressure conditions, the adhesive between the resin plate and the crystal rod is cured for 0.5 to 2 hours until it is initially cured.

[0023] As an alternative optimization of the bonding method for 8-inch semiconductor ingots described above: In S4, the crystal orientation deviation is the required horizontal crystal orientation X of the ingot. 需 and perpendicular crystal orientation Y 需 .

[0024] As an alternative optimization of the bonding method for 8-inch semiconductor ingots described above: in S4, X 实 and Y 实 Compared with the degree of crystal orientation deviation, this is X. 实 and X 需 Comparison, Y 实 and Y 需 Compare, if X 实 =X 需 and Y 实 =Y 需 If the crystal rod bonding is successful, then the bonding is qualified.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention provides a bonding method suitable for 8-inch semiconductor ingots. The method uses a crystal orientation device to calculate the angle α between the ingot and the crystal holder, and the rotation angle β of Notch around the ingot's axis. Then, the crystal holder is rotated by α, and the ingot is rotated by β around its axis. The crystal holder is raised so that the circumferential surface of the ingot is pressed firmly against the arc-shaped top surface of the resin board. Pressure is maintained for curing for 0.5–2 hours until the adhesive between the ingot and the resin board is initially cured. A crystal orientation re-inspection instrument is used to inspect the initially cured ingot to obtain Z, and X is calculated. 实 and Y 实 By comparing the horizontal and vertical crystal orientations of the desired crystal rod with the comparison results and adjusting the crystal rod until the bonding is qualified, the accurate actual horizontal and vertical crystal orientations of the initially cured crystal rod can be obtained, thus improving the bonding accuracy of 8-inch semiconductor crystal rods. Attached Figure Description

[0027] Figure 1 It is the angle between the crystal rod and the crystal holder;

[0028] Figure 2 This is a diagram of Notch rotation. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art, such as the structure of the sticking device, the method for determining the center of the crystal rod end face, etc.

[0030] A bonding method suitable for 8-inch semiconductor ingots includes the following steps:

[0031] S1. Using a crystal orientation device, determine the angles α and β required for bonding the 8-inch crystal rod based on the crystal orientation deviation. Then, rotate the 8-inch crystal rod around its axis to rotate its Notch by an angle β, and place it horizontally on the bonding device.

[0032] like Figure 1 As shown, α is the horizontal deflection angle of the crystal rod relative to the crystal holder, that is, the angle between the crystal rod and the crystal holder, which determines the vertical crystal orientation of the crystal rod; β is the vertical deflection angle, that is, the angle of Notch's rotation around the crystal rod axis, which determines the horizontal crystal orientation of the crystal rod.

[0033] Specifically:

[0034] S11, an 8-inch crystal rod is placed horizontally on the crystal orientation device, with one end face of the crystal rod facing the X-ray emitting tube and receiving tube of the crystal orientation device; in this embodiment, before placing the crystal rod on the crystal orientation device, the center of the circle on the end face of the crystal rod is determined, and during the placement of the crystal rod, the end face with the determined center of the circle is made to face the X-ray emitting tube and receiving tube.

[0035] S12, Notch is vertically upward, and the crystal rod is rotated around the center point of the above end face until the X-ray detector of the crystal orientation device shows the maximum reflection intensity. At this time, the movement angle of the crystal rod is α.

[0036] S13. Rotate the crystal rod 90° clockwise along the central axis. Rotate the crystal rod around the center point of the above end face until the X-ray detector of the crystal orientation device shows the maximum reflection intensity. At this time, the movement angle of the crystal rod is β.

[0037] S14. The crystal rod is rotated by an angle β around its axis with Notch facing upwards and placed horizontally on the sticking device.

[0038] S2. Place the crystal holder with the resin plate on the adhesive rod device, rotate the crystal holder to a rotation angle of α, and then fix it on the adhesive rod device.

[0039] Adhesive is applied to the bottom and top surfaces of the resin board, and the bottom surface of the resin board is bonded to the top surface of the crystal holder. In this embodiment, the top surface of the resin board is an arc surface, and the bottom surface is a horizontal surface. The bottom surface is bonded to the upper surface of the crystal holder, and the top surface is bonded to the circumferential surface of the crystal ingot. The length of the resin board is greater than the length of the crystal ingot but less than or equal to the length of the crystal holder, ensuring that the portion of the circumferential surface of the crystal ingot facing the resin board is completely bonded within the arc surface of the vertical plate. If a portion of the arc surface of the crystal ingot is not bonded within the arc surface, the unbonded portion will be cut off during subsequent wire cutting, causing damage to the silicon wafer.

[0040] In this embodiment, the crystal holder is placed on the rotary table of the bonding device, and the rotary table is rotated so that the angle between the crystal holder and the crystal rod is α before fixing the crystal holder.

[0041] S3. Raise the crystal holder to make the crystal rod and the arc-shaped top surface of the resin plate fit together and press firmly until the glue between the resin plate and the crystal rod is initially cured.

[0042] Specifically:

[0043] S31. Raise the crystal holder so that the circumferential surface of the crystal rod is in contact with and pressed tightly against the arc-shaped top surface of the resin plate. In this embodiment, the crystal holder is moved upward by lifting the rotary table in the bonding device, so that the arc-shaped top surface of the resin plate is in contact with the part of the circumferential surface of the crystal rod facing the resin plate.

[0044] S32. When the pressure between the resin plate and the crystal rod reaches 70-90 kg, the crystal holder stops moving. In this embodiment, the pressure between the resin plate and the crystal rod is 80 kg.

[0045] S33. Under the above pressure conditions, the adhesive between the resin plate and the crystal rod is cured for 0.5 to 2 hours until it is initially cured. In this embodiment, the curing time of the adhesive between the resin plate and the crystal rod is 0.6 hours.

[0046] S4. Remove the pre-cured crystal rod for re-inspection. If the crystal rod bonding is qualified, continue curing the adhesive between the crystal rod and the resin board until bonding is complete. Otherwise, adjust the deflection angle of the crystal rod and the crystal holder until the crystal rod bonding is qualified. Ensure the accuracy of crystal rod bonding.

[0047] In this embodiment, a crystal orientation re-inspection instrument is used to re-inspect the pre-cured crystal rod. When the plane formed by the tangents centered at Notch is parallel to the plane formed by the rays emitted by the X-ray tube and received by the X-ray tube, the measured angle is the vertical crystal orientation; when the plane formed by the tangents centered at Notch is perpendicular to the plane formed by the rays emitted by the X-ray tube and received by the X-ray tube, the measured angle is the horizontal crystal orientation. Therefore, the crystal orientation re-inspection instrument can only detect crystal rods with β of 0° or ±90°. However, for any other angular distribution of β between -90° and 90°, the crystal orientation re-inspection instrument detects a combined value of the horizontal and vertical crystal orientations.

[0048] Therefore, in S4, the Z value is obtained by using a crystal rod orientation re-inspection instrument to detect the pre-cured crystal rod, and the actual horizontal crystal orientation X of the crystal rod is calculated. 实 and the actual perpendicular crystal orientation Y 实 :

[0049] X 实 =Z×cosβ

[0050] Y 实 = Z × cos(90° - |β|)

[0051] X 实 and Y 实 Compared with the degree of crystal orientation deviation, if X 实 and Y 实 If the crystal orientation deviation is the same, the crystal rod bonding is qualified; otherwise, adjust the deflection angles of the crystal rod and the crystal holder until the crystal rod bonding is qualified. It should be noted that the crystal orientation deviation is the required horizontal crystal orientation X of the crystal rod. 需 and perpendicular crystal orientation Y 需 .

[0052] S4,X 实 and Y 实 Compared with the degree of crystal orientation deviation, this is X. 实 and X 需 Comparison, Y 实 and Y 需 Compare, if X 实 =X 需 and Y 实 =Y 需 If the bonding is successful, the crystal rod is properly bonded. This allows for accurate determination of the actual horizontal and vertical crystal orientations of the initially cured crystal rod, improving the bonding accuracy of 8-inch semiconductor crystal rods.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bonding method suitable for 8-inch semiconductor ingots, comprising the following steps: S1. Using a crystal orientation device, determine the angles α and β that need to be deflected for bonding the 8-inch crystal rod according to the crystal orientation deviation. Then, rotate the 8-inch crystal rod around its axis to make its Notch rotate by an angle β, and place it horizontally on the bonding device. S2. Place the crystal holder with the resin plate on the adhesive rod device, rotate the crystal holder to a rotation angle of α, and then fix it on the adhesive rod device. S3. Raise the crystal holder to make the crystal rod and the arc-shaped top surface of the resin plate fit together and press tightly until the glue between the resin plate and the crystal rod is initially cured. S31. Raise the crystal holder so that the circumferential surface of the crystal rod is in contact with and pressed tightly against the arc-shaped top surface of the resin plate. S32. When the pressure between the resin plate and the crystal rod reaches 70~90Kg, the crystal holder stops moving; S33. Under the above pressure conditions, the adhesive between the resin plate and the crystal rod is cured for 0.5~2 hours until it is initially cured; S4. Take out the pre-cured crystal rod for re-inspection. If the crystal rod is bonded properly, continue to cure the glue between the crystal rod and the resin board until the bonding is complete. Otherwise, adjust the deflection angle of the crystal rod and the crystal holder until the crystal rod is bonded properly. The feature is that: in S4, the Z-axis of the pre-cured crystal rod is obtained by using a crystal rod orientation re-inspection instrument, and the actual horizontal crystal orientation X of the crystal rod is calculated. 实 and the actual perpendicular crystal orientation Y 实 : X 实 =Z×cosβ AND 实 =Z×cos(90°-|β|) X 实 and Y 实 Compared with the degree of crystal orientation deviation, if X 实 and Y 实 If the crystal rod is bonded to the same degree as the crystal orientation deviation, then the crystal rod bonding is qualified; otherwise, adjust the deflection angle of the crystal rod and the crystal holder until the crystal rod bonding is qualified. The crystal orientation deviation is the required horizontal crystal orientation X of the crystal rod. 需 and perpendicular crystal orientation Y 需 ; X 实 and Y 实 Compared with the degree of crystal orientation deviation, this is X. 实 and X 需 Comparison, Y 实 and Y 需 Compare, if X 实 =X 需 and Y 实 =Y 需 If the crystal rod bonding is successful, then the bonding is qualified.

2. The bonding method for an 8-inch semiconductor ingot as described in claim 1, characterized in that: S1 includes: The S11, 8-inch crystal rod is placed horizontally on the crystal orientation equipment, with one end face of the crystal rod facing the X-ray emission tube and receiving tube of the crystal orientation equipment; S12, Notch is vertically upward, the crystal rod is rotated around the center point of the above end face until the crystal orientation device shows the maximum reflection intensity, at which point the movement angle of the crystal rod is α; S13. Rotate the crystal rod 90° clockwise along the central axis. Rotate the crystal rod around the center point of the above end face until the crystal orientation device shows the maximum reflection intensity. At this time, the movement angle of the crystal rod is β. S14. The crystal rod is rotated by an angle β around its axis with Notch facing upwards and placed horizontally on the sticking device.

3. The bonding method for an 8-inch semiconductor ingot as described in claim 1, characterized in that: In step S2, adhesive is applied to the bottom and top surfaces of the resin plate, and the bottom surface of the resin plate is bonded to the top surface of the crystal holder.

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