Gallium nitride wafer processing

Abstract

The application discloses a gallium nitride wafer processing technology and belongs to the field of semiconductors. The gallium nitride wafer processing technology comprises the following steps: forming a deposition layer on a ceramic carrier plate; adhering one end surface of a gallium nitride wafer to the deposition layer of the ceramic carrier plate, and fixing and connecting the gallium nitride wafer to the deposition layer through a permanent bonding technology; performing a metal ion implantation and ion activation process on the other end surface of the wafer; coating a bonding agent on the other end surface of the wafer and bonding a glass carrier plate; and removing the deposition layer by applying an etchant around the deposition layer, so as to remove the ceramic carrier plate from the wafer.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor, in particular to a gallium nitride wafer processing technology. BACKGROUND

[0002] In the gallium nitride wafer processing technology, the existing bearing mode is difficult to realize for. For example, when the glass carrier plate is bonded or carried, the bonding agent will fail in the process step involving high temperature, so that the carrier plate cannot be bonded with the wafer. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a gallium nitride wafer processing technology.

[0004] The object of the present application can be achieved by the following technical solutions:

[0005] A gallium nitride wafer processing technology, comprising the following steps:

[0006] Forming a deposition layer on the ceramic carrier plate;

[0007] Bonding one end face of the gallium nitride wafer on the deposition layer of the ceramic carrier plate, and fixing the gallium nitride wafer on the deposition layer by permanent bonding technology;

[0008] Carrying out metal ion implantation and ion activation process on the other end face of the wafer;

[0009] Coating a bonding agent on the other end face of the wafer, and bonding a glass carrier plate;

[0010] By applying etchant around the deposition layer to remove the deposition layer, and then removing the ceramic carrier plate from the wafer.

[0011] Optionally, during the processing of the other end face of the wafer, the wafer is adsorbed and fixed from the end face of the ceramic carrier plate away from the wafer by virtue of the porous structure of the ceramic carrier plate;

[0012] A copper seed layer is arranged on the back surface of the wafer, and the copper seed layer at the cutting path of the wafer is covered by the photoresist; a copper metal block is formed on the copper seed layer not covered by the photoresist; the photoresist is removed, and the copper seed layer above the cutting path is etched;

[0013] A copper metal block is formed on the copper seed layer;

[0014] The part of the wafer at the lower end of the cutting path is further cut by laser;

[0015] The wafer is transferred to a mold frame, the bonding agent is removed, and the glass carrier plate is removed;

[0016] The wafer is cracked to form a die.

[0017] Optionally, the glass carrier plate is fixed by a suction cup during the process of applying the etchant around the deposition layer.

[0018] Optionally, the deposition layer is silicon dioxide.

[0019] Optionally, the etchant is hydrofluoric acid.

[0020] Advantages of the present application:

[0021] The process of the present application forms a deposition layer on the ceramic carrier plate, and then forms a permanent bond between the deposition layer and the gallium nitride wafer, thereby achieving stable mounting of the wafer, and the wafer and the ceramic carrier plate can be fixed in the subsequent metal process. After the process involving high temperature is completed, the deposition layer can be removed by etching, thereby releasing the fixation of the wafer and the ceramic carrier plate. BRIEF DESCRIPTION OF DRAWINGS

[0022] The present application will be further described below with reference to the accompanying drawings.

[0023] Fig. 1 、 2 Process flow chart of the present application;

[0024] Figs. 3-6 Process flow chart of another embodiment of the present application.

[0025] Correspondence between the labels in the drawings and the components is as follows:

[0026] 1 ceramic carrier plate

[0027] 2 deposition layer

[0028] 3 wafer

[0029] 4 metal

[0030] 5 glass carrier plate

[0031] 6 adhesive

[0032] 7 suction cup

[0033] 8 copper seed layer

[0034] 9 release agent

[0035] 10 photoresist

[0036] 11 copper metal block

[0037] 13 mold DETAILED DESCRIPTION

[0038] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0039] As shown in the figure, a gallium nitride wafer 3 processing technology comprises the following steps: Figs. 1-2

[0040] forming a deposition layer 2 on a ceramic carrier plate 1;

[0041] attaching one end surface of the gallium nitride wafer 3 to the deposition layer 2 of the ceramic carrier plate 1, and fixing the gallium nitride wafer 3 to the deposition layer 2 by permanent bonding technology;

[0042] carrying out metal ion implantation and ion activation processes on the other end surface of the wafer 3;

[0043] applying a bonding agent 6 on the other end surface of the wafer 3 and bonding a glass carrier plate 5; additionally, a releasing agent 9 can be applied on the bonding agent 6;

[0044] applying an etchant around the deposition layer 2 to remove the deposition layer 2, and thus removing the ceramic carrier plate 1 from the wafer 3.

[0045] Optionally, during the processing of the other end surface of the wafer 3, the wafer 3 is adsorbed and fixed from the end surface of the ceramic carrier plate 1 away from the wafer 3 by virtue of the porous structure of the ceramic carrier plate 1.

[0046] Specifically, by forming the deposition layer 2 on the ceramic carrier plate 1, and then forming permanent bonding between the deposition layer 2 and the gallium nitride wafer 3, the stable mounting of the wafer 3 is realized, and the fixation of the wafer 3 and the ceramic carrier plate 1 can be maintained in subsequent metal processes. After the process involving high temperature is completed, the deposition layer 2 can be removed by etching, and thus the fixation of the wafer 3 and the ceramic carrier plate 1 is released.

[0047] Optionally, during the process of applying the etchant around the deposition layer 2, the glass carrier plate 5 is adsorbed and fixed by the suction cup 7.

[0048] Optionally, the deposition layer 2 is silicon dioxide.

[0049] Optionally, the etchant is hydrofluoric acid.

[0050] ​In some other embodiments of the present application, a method for forming the copper blocks 11 on the back side of the wafer 3 is also disclosed, which comprises the following steps: arranging a copper seed layer 8 on the back side of the wafer 3, and covering the copper seed layer 8 at the cutting path of the wafer 3 by the photoresist 10. Forming the copper blocks 11 on the copper seed layer 8 not covered by the photoresist 10. Removing the photoresist 10, and etching the copper seed layer 8 above the cutting path, at this time the copper blocks 11 act as a mask, and the copper seed layer 8 not covered by the copper blocks 11 is etched away.

[0051] Further cutting the wafer 3 at the lower end of the cutting path by laser; transferring the wafer 3 to a mold frame 13, and removing the bonding agent 6, and removing the glass carrier plate 5; and breaking the wafer 3 to form dies.

[0052] That is, before the copper blocks 11 are formed, the copper seed layer 8 on the back side of the wafer 3 is cut according to the shape of the cutting path, then the copper blocks 11 formed subsequently are also distributed along the dies, and a whole copper metal is not formed on the back side of the wafer 3. In this way, the relatively small copper blocks 11 formed have relatively small stress between each copper block 11 and the wafer 3, and the undesired stress between the whole copper metal and the wafer 3 can be avoided, and the wafer 3 is not damaged.

[0053] In the description of the present specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0054] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A process for processing a gallium nitride wafer, the process comprising: providing a gallium nitride wafer; and exposing the wafer to a plasma comprising hydrogen and nitrogen. The method comprises the following steps: forming a deposition layer on a ceramic carrier plate; attaching one end surface of the wafer to the deposition layer of the ceramic carrier plate and fixing the wafer to the deposition layer by permanent bonding technology; carrying out ion implantation and ion activation processes on the front surface of the wafer; applying a bonding agent to the other end surface of the wafer and bonding a glass carrier plate thereto; after the high-temperature process is completed, removing the ceramic carrier plate from the wafer by applying an etchant around the deposition layer to remove the deposition layer; arranging a copper seed layer on the back surface of the wafer and covering the copper seed layer at the cutting path of the wafer with photoresist; and forming a copper metal block on the copper seed layer not covered by the photoresist; removing the photoresist and etching the copper seed layer above the cutting path; forming a copper metal block on the copper seed layer; further cutting the wafer at the lower end of the cutting path by laser; transferring the wafer to a mold frame, removing the bonding agent, and removing the glass carrier plate; breaking the wafer to form dies.

2. The gallium nitride wafer processing process of claim 1 wherein, During the processing of the other end surface of the wafer, the wafer is adsorbed and fixed away from the end surface of the wafer by the porous structure of the ceramic carrier plate.

3. The gallium nitride wafer processing process of claim 1 wherein, During the process of applying the etchant around the deposition layer, the glass carrier plate is adsorbed and fixed by a suction cup.

4. The gallium nitride wafer processing process of claim 1 wherein, The deposition layer is silicon dioxide.

5. The gallium nitride wafer processing process of claim 1 wherein, The etchant is hydrofluoric acid.

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