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CN-122003121-A - Method and device for reducing breaking rate of IGBT epitaxial wafer

CN122003121ACN 122003121 ACN122003121 ACN 122003121ACN-122003121-A

Abstract

The invention belongs to the technical field of semiconductor manufacturing, in particular to a method and a device for reducing the breaking rate of an IGBT epitaxial wafer, comprising the following steps of S1, loading and positioning a wafer in a supporting disc at the top of a base main body in an epitaxial machine, and positioning the wafer through a stop block on the supporting disc; S2, performing the process, namely starting and implementing an epitaxial growth process, and S3, actively separating, namely starting a separating assembly arranged on the supporting disc after the epitaxial growth is completed, so that the separating assembly generates vibration acting on the wafer, and separating the wafer from the sticky part of the supporting disc. According to the wafer positioning device, the stop block is arranged to position the wafer, so that the wafer is prevented from being adhered to the inner wall of the side step due to the increase of the volume in the epitaxial growth process, and the risk of cracking caused by a small notch at the adhered part during the wafer taking is reduced.

Inventors

  • CHEN CHENG
  • GAO XUAN
  • YANG YIN
  • ZHANG YU

Assignees

  • 上海晶盟硅材料有限公司

Dates

Publication Date
20260508
Application Date
20260121

Claims (10)

  1. 1. A method for reducing the breaking rate of an IGBT epitaxial wafer is characterized by comprising the following steps: S1, loading and positioning, namely placing a wafer (4) in a supporting disc (2) at the top of a base main body (1) in an epitaxial machine, and positioning the wafer (4) through a stop block (3) on the supporting disc (2); s2, performing a process, namely starting and implementing an epitaxial growth process; S3, active separation, namely starting a separation assembly arranged on the supporting disc (2) after epitaxial growth is completed, so that the separation assembly generates vibration acting on the wafer (4) to separate the wafer (4) from the adhesion part of the supporting disc (2).
  2. 2. The device for reducing the breaking rate of the IGBT epitaxial wafer is suitable for the method for reducing the breaking rate of the IGBT epitaxial wafer according to claim 1, and is characterized in that in the step S3, the separation assembly comprises a piezoelectric ceramic block (6), and the piezoelectric ceramic block (6) is embedded in a mounting groove (5) formed in the surface of the supporting disc (2).
  3. 3. The device for reducing the breaking rate of the IGBT epitaxial wafer according to claim 2 is characterized in that a plurality of baffle blocks (3) are arranged and uniformly distributed on the inner wall of the supporting disc (2).
  4. 4. The device for reducing the breaking rate of the IGBT epitaxial wafer according to claim 3, wherein the piezoelectric ceramic block (6) is arranged in a circular shape, and a blowing assembly is connected to a center hole of the piezoelectric ceramic block and is used for introducing gas into a contact area between the wafer (4) and the supporting disc (2).
  5. 5. The device for reducing the breaking rate of the IGBT epitaxial wafer of claim 4, wherein the blowing assembly comprises a cavity (13) arranged in the supporting disc (2), an air inlet pipe (17) is communicated with the bottom of the cavity (13), and the side edge of the air inlet pipe is communicated with the central hole of the piezoelectric ceramic block (6) through a connecting channel (11).
  6. 6. The device for reducing the breaking rate of the IGBT epitaxial wafer according to claim 5 is characterized in that a movable block (8) is movably arranged in a central hole of the piezoelectric ceramic block (6), the upper end face of the movable block (8) is flush with the upper end face of the piezoelectric ceramic block (6) to block the central hole, and a driving assembly is arranged in the cavity (13) and used for driving the movable block (8) to move to open or close the central hole.
  7. 7. The device for reducing the breaking rate of the IGBT epitaxial wafer according to claim 6 is characterized in that the driving assembly comprises a movable plate (14), a connecting block (15) which is inserted into the air inlet pipe (17) in a sealing sliding mode is fixed at the bottom of the movable plate (14), a pull rope (10) is connected to the side edge of the movable plate (14), and the other end of the pull rope (10) penetrates through the connecting channel (11) and is connected to the bottom of the movable block (8).
  8. 8. The device for reducing the breaking rate of the IGBT epitaxial wafer of claim 6 is characterized in that a movable cavity (7) is formed in the inner wall of a central hole of the piezoelectric ceramic block (6), a limiting block (9) is arranged on the side wall of the movable block (8), the limiting block (9) is limited to slide in the movable cavity (7), and a first spring (12) positioned below the limiting block (9) is arranged in the movable cavity (7).
  9. 9. The device for reducing the breaking rate of the IGBT epitaxial wafer of claim 7, wherein a through hole (16) is formed in the centers of the movable plate (14) and the connecting block (15), a vertical rod (18) is arranged in the through hole (16) in a sealing sliding manner, the top end of the vertical rod is fixed to the top of the cavity (13), and a spring II (19) is sleeved on the vertical rod (18).
  10. 10. The device for reducing the breaking rate of the IGBT epitaxial wafer of claim 5, wherein a plurality of support plates (2) are arranged and are embedded on the surface of the base main body (1), a main pipeline (20) is arranged in the center of the base main body (1), the main pipeline (20) is respectively communicated to the lower parts of the support plates (2) through a plurality of branch pipelines (21), and air inlet pipes (17) at the bottoms of the support plates (2) are correspondingly inserted into the branch pipelines (21).

Description

Method and device for reducing breaking rate of IGBT epitaxial wafer Technical Field The invention belongs to the technical field of semiconductor manufacturing, and particularly relates to a method and a device for reducing the breaking rate of an IGBT epitaxial wafer. Background IGBT (insulated gate bipolar transistor) is used as a core power semiconductor device, and is widely applied to key fields such as new energy automobiles, rail transit, smart grids, power electronic converters and the like by virtue of excellent performances such as high withstand voltage, low conduction loss, rapid switching and the like, and the product quality and the preparation stability of the IGBT directly determine the operation reliability of downstream equipment. The epitaxial wafer is used as a core basic structure of the IGBT device, the preparation process is a key link in the IGBT production flow, and the substrate with the thick epitaxial structure becomes the mainstream choice because the substrate can meet the performance requirements of the IGBT device in high-voltage and high-current scenes. However, in the existing preparation process of the IGBT thick epitaxial wafer, the problem of wafer breakage restricts the improvement of production efficiency and product yield for a long time, and the problem becomes a technical bottleneck to be solved in industry. Industrial practice and research show that the chipping phenomenon mainly occurs in the epitaxial growth stage and the subsequent clamping process, and the core causes of the chipping phenomenon comprise the following two aspects: On the one hand, atomic-scale adhesion is easy to occur between the end face of the wafer and the step structure of the crystal growth base in the epitaxial growth process. In the conventional crystal orientation of the IGBT epitaxial wafer, the atomic density among <111> crystal faces is obviously lower than that of other crystal orientations, the number of atomic bond combinations is small, and the bonding force is weak, so that a crystal orientation area becomes a mechanical weak point of the wafer, particularly for the wafer with the [100] crystal orientation and notch (notch) located in the {100} crystal face, the breakage cracks are concentrated in the X direction in actual production, the probability of adhesion between a base step in the direction and the end face of the wafer is extremely high, tiny notches are easy to generate at the adhesion position during wafer taking, and the notch rapidly expands under the stress effect, so that the wafer is finally broken. On the other hand, the thick epitaxial growth process itself can cause the diameter of the wafer to be increased compared with that of the initial substrate, and in the subsequent process links such as sorting, transferring and the like, the clamping jaws need to clamp the wafer, so that uneven mechanical stress is easily generated during clamping, and the wafer is clamped and crushed. Therefore, the invention provides a method and a device for reducing the breaking rate of an IGBT epitaxial wafer. Disclosure of Invention In order to overcome the deficiencies of the prior art, at least one technical problem presented in the background art is solved. The technical scheme adopted for solving the technical problems is that the method for reducing the breaking rate of the IGBT epitaxial wafer comprises the following steps: s1, loading and positioning, namely placing a wafer in a supporting disc at the top of a base main body in an epitaxial machine, and positioning the wafer through a stop block on the supporting disc; s2, performing a process, namely starting and implementing an epitaxial growth process; s3, actively separating, namely starting a separating assembly arranged on the supporting disc after the epitaxial growth is finished, so that the separating assembly generates vibration acting on the wafer, and separating the wafer from the adhesion part of the supporting disc. The device for reducing the breaking rate of the IGBT epitaxial wafer is suitable for the method for reducing the breaking rate of the IGBT epitaxial wafer, in the step S3, the separation assembly comprises a piezoelectric ceramic block, and the piezoelectric ceramic block is inlaid in a mounting groove formed in the surface of the supporting disc. Preferably, the stop blocks are arranged in a plurality and uniformly distributed on the inner wall of the supporting disc. Preferably, the piezoelectric ceramic block is arranged in a circular ring shape, and a blowing assembly is connected to the center hole of the piezoelectric ceramic block and used for guiding gas into the contact area between the wafer and the supporting disc. Preferably, the air blowing component comprises a cavity arranged in the supporting disc, an air inlet pipe is communicated with the bottom of the cavity, and the side edge of the air blowing component is communicated with the central hole of the piezoelectric ceramic bloc