CN113714650A

CN113714650A - Method for manufacturing wafer

Info

Publication number: CN113714650A
Application number: CN202110980368.9A
Authority: CN
Inventors: 李春昊; 郝宏伟; 巫礼杰; 任达; 仰瑞; 贺少鹏; 童灿钊; 尹建刚; 高云峰
Original assignee: Han s Laser Technology Industry Group Co Ltd
Current assignee: Shenzhen Hans Semiconductor Equipment Technology Co Ltd
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2021-11-30

Abstract

The present application provides a method of manufacturing a wafer, the method comprising the steps of: forming a peeling layer along a C-plane at a depth position corresponding to the thickness of the wafer from the first surface in the ingot by irradiation of laser light; adhering a first surface of the ingot to a solid substrate through a bonding layer; applying an external force to the solid substrate and/or the ingot at the end of the peeling layer away from the first surface to cause relative movement of the ingots at the two ends of the peeling layer, thereby peeling off a portion of the ingot at the peeling layer interface to produce a wafer; and reducing the adhesiveness of the adhesive layer, and separating the resulting wafer from the solid substrate. The stripping process of the crystal ingot in the manufacturing method is simple and reliable, the production cost is reduced, and the production efficiency is improved.

Description

Method for manufacturing wafer

Technical Field

The present application relates to the field of semiconductor device manufacturing technology, and more particularly, to a method for manufacturing a wafer.

Background

In the semiconductor industry, wafers of materials such as silicon carbide (SiC), silicon (Si), sapphire (Al2O3), and glass are commonly used as substrates for device fabrication. Conventional wafer preparation methods are to strip the ingot into sheets using wire saw cutting or "cold separation".

However, the wire saw cutting method has serious material loss, and the slicing process can cause most (70-80%) of the ingot to be abandoned. Particularly for high-hardness SiC materials (Mohs hardness of 9.5), the sawing wire cutting mode has the disadvantages of large material loss, too low efficiency, serious cutter abrasion, environmental pollution and the like, and the development of the SiC industry is seriously restricted.

In the cold separation method, the SiC ingot material and the PDMS are bonded together by using a spin-on glue. The spin coating process of glue increases the process complexity and is not conducive to mass production. In addition, liquid nitrogen is adopted for refrigeration in the separation scheme, and extra production cost can be increased by taking the liquid nitrogen as a consumable material. At the same time, the introduction of refrigeration devices also complicates the equipment manufacturing process. The above problems limit the application of this solution in industrial production.

Disclosure of Invention

The present application provides a method for manufacturing a wafer to solve the above-mentioned technical problems of the background art.

The technical scheme adopted by the application is a wafer manufacturing method for separating an ingot to obtain wafers, wherein the ingot is provided with a C axis and a C surface vertical to the C axis, and is also provided with a first surface, and the first surface and the C surface are parallel to each other or form an included angle, and the manufacturing method is characterized by comprising the following steps of:

forming a peeling layer along a C-plane at a depth position corresponding to the thickness of the wafer from the first surface in the ingot by irradiation of laser light;

adhering a first surface of the ingot to a solid substrate through a bonding layer;

applying an external force to the solid substrate and/or the ingot at an end of the exfoliation layer remote from the first surface, thereby exfoliating a portion of the ingot at the exfoliation layer interface to produce a wafer; and

and reducing the adhesiveness of the bonding layer, and separating the produced wafer from the solid substrate.

In the manufacturing method of the wafer, the part to be stripped of the crystal ingot of the thin layer is fixed on the solid substrate through the bonding layer, the problem that the part to be stripped of the crystal ingot of the thin layer is not easy to fix is solved, the part to be stripped of the crystal ingot and the body part of the crystal ingot can move relatively by using the solid substrate as a medium, the part to be stripped of the crystal ingot and the body part of the crystal ingot are separated, and finally the wafer is separated from the solid substrate to obtain the wafer.

Further, the adhesive material layer is a thermal release adhesive, a light release adhesive, or a soluble adhesive material.

Further, wherein the adhesive material layer is a thermal release adhesive, the adhesive property of the bonding layer is reduced, and the step of separating the resulting wafer from the solid substrate includes:

heating the viscous material layer to heat and melt the viscous material layer, so as to lose or reduce viscosity; and

separating the wafer from the solid substrate.

Further, wherein the adhesive material layer is a light separation adhesive, the adhesive property of the bonding layer of the connection layer is reduced, and the step of separating the resulting wafer from the solid substrate includes:

irradiating the viscous material layer to enable the viscous material layer to be subjected to photodecomposition, so that the viscosity is lost or reduced; and

separating the wafer from the solid substrate.

Further, wherein the adhesive material layer is a soluble adhesive material, the step of reducing the adhesive bonding property of the bonding layer comprises the steps of:

introducing corrosive liquid into the viscous material layer to dissolve the viscous material layer in the corrosive liquid, thereby losing or reducing the viscosity; and

separating the wafer from the solid substrate.

Further, the step of introducing corrosive liquid into the viscous material layer to dissolve the viscous material layer in the corrosive liquid so as to lose viscosity further comprises:

a plurality of permeation holes communicated to the surface close to the viscous material layer are formed in the solid substrate; and

and introducing corrosive liquid into the penetration hole to enable the corrosive liquid to penetrate into the surface of the solid substrate to react with the viscous material layer, so that the viscous material layer is dissolved in the corrosive liquid.

Further, the solid substrate is made of a soluble material, the adhesive property of the bonding layer of the connection layer is reduced, and the step of separating the generated wafer from the solid substrate further comprises:

and soaking the whole of the wafer and the solid substrate in an etching solution to dissolve the solid substrate and the viscous material layer in the etching solution to obtain the wafer.

Further, the step of forming a peeling layer at a depth position equivalent to the wafer thickness from the first surface in the ingot by irradiation of the laser light further includes:

a laser beam condensing point having a wavelength transparent to the ingot is positioned at a depth from the first surface corresponding to a thickness of the wafer to be grown, and a plurality of sets of modified portion arrays forming the peeling layer are formed on the C-plane inside the ingot by laser scanning.

a laser beam converging point having a wavelength transparent to the ingot is positioned at a depth from the first surface corresponding to a thickness of the wafer to be grown, and a modified portion and a crack propagating from the modified portion in each direction of the C-plane are formed in the ingot at the depth by laser irradiation, and the crack forms a peeling layer.

Further, the step of positioning a laser beam converging point having a wavelength transparent to the ingot at a depth from the first surface corresponding to a thickness of the wafer to be grown, and forming a modified portion and a crack propagating from the modified portion in each direction of the C-plane inside the ingot at the depth by laser irradiation, the crack forming release layer further includes:

heating the peeling layer or imparting vibration to the ingot, thereby promoting the crack to propagate in each direction of the C-plane.

Further, the separated surface of the peeled wafer is ground to be processed into a smooth surface.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of an ingot in which a C axis coincides with a vertical line in a method for manufacturing a wafer according to an embodiment of the present application;

fig. 2 is a sectional view of an ingot in which a C-axis is inclined from a vertical line in the manufacturing method of the wafer shown in fig. 1;

FIG. 3 is a block flow diagram of a method of fabricating the wafer shown in FIG. 1;

FIG. 4 is a schematic diagram illustrating a step of forming a lift-off layer in the method of manufacturing the wafer shown in FIG. 1;

FIG. 5 is a schematic structural diagram of a laser forming a modified portion array on a C-plane in the manufacturing method of the wafer shown in FIG. 1;

FIG. 6 is a schematic structural view of a laser forming cracks on a C-plane in the manufacturing method of the wafer shown in FIG. 1;

FIG. 7 is a view schematically showing a structure in which an ingot is provided on a solid substrate via a bonding layer in the manufacturing method of the wafer shown in FIG. 1;

FIG. 8 is a view schematically illustrating a structure in which an ingot is peeled off by applying an external force in the method for manufacturing the wafer shown in FIG. 1;

FIG. 9 is a view schematically illustrating another example of a structure in which an ingot is provided on a solid substrate via a bonding layer in the method of manufacturing the wafer shown in FIG. 7;

FIG. 10 is a schematic view of a structure in which a wafer is separated from a solid substrate by heating in the method for manufacturing the wafer shown in FIG. 1;

FIG. 11 is a schematic view of a structure to be separated from a solid substrate by light irradiation in the method for manufacturing a wafer shown in FIG. 1;

fig. 12 is a schematic view showing a structure in which a wafer is separated from a solid substrate by dissolving the wafer in an etching solution in the method for manufacturing the wafer shown in fig. 1.

Reference numerals:

100. a crystal ingot; 110. an ingot body portion; 120. a portion of the ingot to be stripped; 130. a C axis; 140. c surface; 150. a first surface; 160. a vertical line;

200. a laser processing device; 300. a peeling layer; 310. a modifying unit; 320. cracking; 400. a bonding layer; 500. a solid substrate; 510. a penetration hole; 600. a mechanical structure; 700. a temperature control assembly; 800. a light source; 810. ultraviolet light; 900. and (4) corrosive liquid.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It should be noted that, when a meta-structure is referred to as being "fixed" or "disposed" to another meta-structure, it may be directly on the other meta-structure or indirectly on the other meta-structure. When a meta structure is referred to as being "connected to" another meta structure, it can be directly connected to the other meta structure or indirectly connected to the other meta structure.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, refer to an orientation or positional relationship illustrated in the drawings that is used solely to facilitate the description of the application and to simplify the description, and do not indicate or imply that the referenced device or element structure must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of some applications, "plurality" means two or more unless specifically limited otherwise.

The present application provides a method of manufacturing wafers by which a solid material, such as ingot 100, may be prepared into a number of wafers. Wherein ingot 100 has a first surface 150 and a second surface opposite first surface 150. The material of ingot 100 may be SiC, Si, Al2O3, glass, or the like. Embodiments of ingot 100 made of SiC are described herein.

Further, ingot 100 also has C-axis 130 and C-plane 140 perpendicular to C-axis 130. In some embodiments, the C-axis 130 is coincident with the perpendicular 160 to the first and second surfaces 150, 160 (i.e., the C-plane 140 is parallel to either the first or second surfaces 150, 150) as shown in fig. 1. In other embodiments, the C-axis 130 is tilted with respect to the perpendicular 160 to the first and second surfaces 150, 160 (i.e., the C-plane 140 forms an off-angle with the first or second surface 150, 160) as shown in fig. 2. Note that the wafer manufacturing method of the present invention can be used regardless of whether the C-axis 130 is inclined with respect to the perpendicular 160 to the first surface 150 and the second surface.

Further, at least one of the first surface 150 and the second surface is a smooth surface. The present application describes embodiments in which first surface 150 is a smooth surface.

Referring to fig. 3, the method for manufacturing the wafer of the present application includes the following steps:

step 100 of forming a peeling layer 300 along a C-plane 140 at a depth position within the ingot 100 from a first surface 150 corresponding to the wafer thickness by irradiation of laser light.

Step 200, adhere first surface 150 of the ingot 100 to a solid substrate 500 via a bonding layer 400.

Step 300, applying an external force to solid substrate 500 and/or ingot 100 at an end of exfoliation layer 300 remote from first surface 150, thereby exfoliating a portion of ingot 100 at the interface with exfoliation layer 300 to produce a wafer.

Step 400, reducing the adhesion of the adhesion layer 400, and separating the resulting wafer from the solid substrate 500.

In the above manufacturing method, the peeling layer 300 is formed inside the ingot 100 to be separated by laser first to ensure the uniformity of the thickness of the thin layer wafer; then, the first surface 150 of the ingot 100 formed with the peeling layer 300 (i.e., the surface of the portion of the ingot 100 to be peeled) is adhered to the solid substrate 500 through the adhesive layer 400, the process is convenient; secondly applying an external force to solid substrate 500 and/or ingot 100 of an end of exfoliation layer 300 remote from first surface 150 to cause relative movement of ingot 100 at both ends of exfoliation layer 300, thereby peeling off a portion of ingot 100 at the exfoliation layer 300 interface to produce a wafer; the peeled thin wafer is removed from the solid substrate 500 by reducing the adhesiveness of the adhesive layer 400, and a wafer is obtained.

It can be seen that the method of the present application fixes the portion to be peeled of the thin layer of ingot 100 to the solid substrate 500 using the adhesive layer 400, solves the problem that the portion to be peeled of the thin layer of ingot 100 is not easily fixed, and uses the solid substrate 500 as a medium, thereby realizing the relative movement between the portion to be peeled of the ingot 100 and the body portion of the ingot 100, and thus the portion to be peeled of the ingot 100 and the body portion of the ingot 100 are separated, and finally the wafer is separated from the solid substrate 500 to obtain the wafer, the whole peeling process is simple and reliable, the production cost is reduced, and the production efficiency is improved.

Referring to fig. 3 and 4, step 100 forms a exfoliation layer 300 along a C-plane 140 within the ingot 100 at a depth corresponding to the wafer thickness from a first surface 150 by irradiation with a laser.

The laser beam irradiation may be performed by using, for example, the laser processing apparatus 200.

The laser processing apparatus 200 includes at least a laser head and a lens, the lens focuses laser emitted from the laser head on the inside of the ingot 100, and the focused laser forms the peeling layer 300 along each direction of the C-plane 140 in the inside of the ingot 100 by driving the laser head to move (for example, driving the laser head to move along the X-axis, Y-axis and Z-axis directions by a three-axis displacement stage (not shown)).

Specifically, the first method, step 100, of forming a exfoliation layer 300 along a C-plane 140 within the ingot 100 at a depth position from a first surface 150 corresponding to the wafer thickness by irradiation of laser light further comprises:

a laser beam converging point having a wavelength transparent to ingot 100 is positioned at a depth from first surface 150 corresponding to the thickness of the wafer to be grown, and an array of modified portions 310 (see fig. 5) is formed along C-plane 140 inside ingot 100 at the depth by laser scanning, the array of modified portions 310 forming peeling layer 300.

Illustratively, assuming that the wafer thickness is D, the laser beam focal point is located on the C-plane 140 at a depth distance D from the first surface 150. It should be noted that in some embodiments, the separation surface of the wafer to be peeled needs to be ground to be processed into a smooth surface, so that a processing margin L is also required in forming the peeled surface along the C-plane 140 inside the ingot 100, that is, the laser beam focal point should be positioned on the C-plane 140 at a depth distance D + L from the first surface 150. Wherein the processing margin L is generally 0 μm to 100. mu.m.

The scanning path of the laser on the C-plane 140 may be multiple parallel lines along the C-plane 140 (as shown in fig. 4), or may be a spiral line or multiple concentric circles.

When the C-axis 130 is aligned with the perpendicular 160 to the first surface 150 and the second surface (i.e., the C-plane 140 is parallel to the first surface 150 or the second surface), the peeling layers 300 formed by the multiple sets of modified portions 310 are parallel to the first surface 150.

If the C-axis 130 is inclined with respect to the perpendicular 160 between the first surface 150 and the second surface (i.e. the C-plane 140 forms an off-angle with the first surface 150 or the second surface), as shown in fig. 2, the peeling layers 300 formed by the plurality of sets of modified portions 310 form an off-angle with the first surface 150. The angle α is generally 0 to 4 degrees, and for example, α is 0 degree, 2 degrees, or 4 degrees.

Method two, step 100, forming a exfoliation layer 300 along C-plane 140 within ingot 100 at a depth from first surface 150 corresponding to the wafer thickness by irradiation with laser light further comprises:

a laser beam having a wavelength transparent to ingot 100 is focused to a depth from first surface 150 corresponding to the thickness of the wafer to be grown, modified portion 310 and crack 320 (see fig. 6) extending from modified portion 310 in each direction of C-plane 140 are formed in ingot 100 at the depth by laser irradiation, and peeling layer 300 is formed by crack 320.

Specifically, the modified parts 310 are continuously formed on the C-plane 140 at the converging point by driving the laser head to move within a range not exceeding the width of the crack 320 isotropically formed on the C-plane 140 from the continuously formed modified parts 310, and the cracks 320 propagated for each modified part 310 are connected to form the peeling layer 300.

Illustratively, assuming that the wafer thickness is D, the laser beam focal point is located on the C-plane 140 at a depth distance D from the first surface 150. It should be noted that in some embodiments, the separation surface of the wafer to be peeled needs to be ground to be processed into a smooth surface, so that a processing margin L is also required in forming the peeled surface along the C-plane 140 inside the ingot 100, that is, the laser beam focal point should be positioned on the C-plane 140 at a depth distance D + L from the first surface 150. Wherein the processing margin L is generally 0nm to 100nm.

In addition, when the C-axis 130 is aligned with the perpendicular 160 to the first surface 150 and the second surface (i.e., the C-plane 140 is parallel to the first surface 150 or the second surface), the peeling layer 300 formed by the crack 320 is parallel to the first surface 150.

If the C-axis 130 is tilted with respect to the perpendicular 160 to the first surface 150 and the second surface (i.e., the C-plane 140 forms an off-angle with the first surface 150 or the second surface), the peeling layer 300 formed by the crack 320 forms an off-angle with the first surface 150. The angle α is generally 0 to 4 degrees, and for example, α is 0 degree, 2 degrees, or 4 degrees.

Here, the laser processing conditions for forming the peeling layer 300 in the ingot 100 for the above-described first and second methods include: selecting 0.1 ps-500 ns pulse laser, wherein the laser frequency is 10-1000 kHz, the laser wavelength is 308-2000 nm, and the energy of a light-gathering point formed by the laser in the crystal ingot 100 is 20 muJ-100 muJ.

For example, the laser processing conditions may be: a200 ns pulsed laser was selected, the frequency of the laser was 500kHz, the wavelength of the laser was 1064nm, and the energy of the spot formed by the laser inside the ingot 100 was 80 μ J.

The processing conditions of the laser may be: a500 ns pulsed laser is selected, the frequency of the laser is 1000kHz, the wavelength of the laser is 2000nm, and the energy of a focal point formed by the laser inside the ingot 100 is 100 muJ.

Further, the step of positioning a laser beam converging point having a wavelength transparent to ingot 100 at a depth from first surface 150 corresponding to a thickness of the wafer to be grown, and forming modified portion 310 and crack 320 extending from modified portion 310 in each direction of C-plane 140 inside ingot 100 at the depth by laser irradiation, wherein the step of forming peeling layer 300 from crack 320 further comprises:

heating the exfoliation layer 300 or imparting vibration to the ingot 100 thereby promoting crack 320 propagation in all directions along the C-plane 140, resulting in better bonding between cracks 320 and easier subsequent exfoliation.

It can be understood that, after the peeling layer 300 is formed inside the ingot 100 by laser irradiation, the bonding force at the peeling layer 300 is weaker than that at the other portions of the ingot 100, and when an external force greater than the bonding force of the peeling layer 300 is applied to the ingot 100, the ingot 100 is divided into two pieces along the peeling plane. Therefore, in order to make the peeling process easier, the bonding force of the peeling layer 300 may be further weakened.

Specifically, in the first method, the crack 320 inside the peeling layer 300 may be promoted by heating the peeling layer 300 through thermal stress to further weaken the bonding force of the peeling layer 300, making the peeling process easier. For example, the peeling surface may be heated by irradiating the peeling surface with a CO2 laser.

Second, the crack 320 in the peeling surface can be promoted to propagate by vibration by giving vibration to the ingot 100 to further weaken the bonding force of the peeling layer 300, making the peeling process easier. For example, ingot 100 may be placed in a water tank for sonication.

Referring to fig. 3 and 7, step 200, first surface 150 of ingot 100 is adhered to solid substrate 500 by bonding layer 400.

The solid substrate 500 may be made of metal, such as Copper (Copper), Steel (Steel), Invar (Invar), etc.; or a non-metal material such as sapphire (Al2O3), silicon carbide (SiC), etc.; or a soluble material such as acrylic sheet.

In the present application, the adhesive layer 400 is an adhesive material layer.

It is understood that the wafer is generally thin, so that it is not preferable to fix the portion to be peeled using the mechanical structure 600 after the peeling layer 300 is formed in the ingot 100. In addition, in the present application, the portion of ingot 100 to be stripped and the body portion of ingot 100 are separated by relative movement of the two by an external force, so that the portion of ingot 100 to be stripped is not fixed by an adsorption structure. Therefore, fixing the portion of ingot 100 to be stripped can be advantageously achieved by using the adhesive material layer to allow relative movement between the portion of ingot 100 to be stripped and the body portion in subsequent processes.

Illustratively, the adhesive material layer may be a thermally releasable adhesive, a light releasable adhesive, or a soluble adhesive material.

For example, in the embodiments of the present application, taking a double-sided adhesive tape as an example, the double-sided adhesive tape may have the properties of a thermal release adhesive, a light release adhesive and a soluble adhesive material at the same time. Specifically, first surface 150 of ingot 100 may be affixed to solid substrate 500 by double-sided adhesive. In addition, the adhesion of the double-sided adhesive tape can be improved by adding a certain amount of heat or applying a certain amount of pressure to the double-sided adhesive tape without damaging the adhesion of the double-sided adhesive tape after the ingot 100 is attached to the solid substrate 500. It can be understood that the double-sided adhesive tape is simple and easy to obtain in industrial production, has low cost, is more convenient and quicker to paste, and can improve the manufacturing efficiency.

In other embodiments, the adhesive material layer may also be a liquid glue or a thermoplastic solid glue, etc.

Referring to fig. 3 and 8, step 300 applies an external force to ingot 100 at an end of solid substrate 500 and/or exfoliation layer 300 remote from first surface 150, thereby exfoliating a portion of ingot 100 at the interface with exfoliation layer 300 to produce a wafer.

Wherein the method of applying an external force to solid substrate 500 and/or ingot 100 (bulk portion of ingot 100) at an end of exfoliation layer 300 remote from first surface 150 comprises stretching, rotating, or prying.

In the embodiment of the present application, the method of applying the external force may be a stretching method, as shown in fig. 8. Specifically, this mode includes fixing the body portion of ingot 100 while applying a vertically downward force to the portion of solid substrate 500, and moving the portion of ingot 100 to be stripped in a vertically downward direction relative to the body portion of ingot 100 by solid substrate 500, thereby stripping the portion of ingot 100 to be stripped from the body portion of ingot 100. Or the portion of ingot 100 to be stripped may be held by solid substrate 500 (e.g., solid substrate 500 may be held on a table), and a vertical upward force may be applied to the body portion of ingot 100 to move the body portion of ingot 100 in a vertically upward direction relative to the portion of ingot 100 to be stripped to thereby strip the body portion of ingot 100 from the portion of ingot 100 to be stripped. And simultaneously or additionally applying a vertical opposing force to the body portion of ingot 100 and the portion of ingot 100 to be stripped, moving the body portion of ingot 100 and the portion of ingot 100 to be stripped in opposing directions, thereby stripping the body portion of ingot 100 from the portion of ingot 100 to be stripped.

In other embodiments, the method of applying the external force may be in a rotational manner. Specifically, this mode includes fixing the body portion of ingot 100 while applying a rotating force in the horizontal direction to the portion of solid substrate 500, and rotating the portion of ingot 100 to be peeled in the horizontal direction with respect to the body portion of ingot 100 by solid substrate 500, thereby peeling the portion of ingot 100 to be peeled from the body portion of ingot 100. Alternatively, the portion of ingot 100 to be stripped may be held by solid substrate 500 (e.g., solid substrate 500 may be held on a table), and a rotational force in the horizontal direction may be applied to the body portion of ingot 100 to rotate the body portion of ingot 100 in the horizontal direction relative to the portion of ingot 100 to be stripped, thereby stripping the body portion of ingot 100 from the portion of ingot 100 to be stripped. And simultaneously or additionally applying horizontally opposite rotational forces to the body portion of ingot 100 and the portion of ingot 100 to be stripped, rotating the body portion of ingot 100 and the portion of ingot 100 to be stripped in opposite directions horizontally, thereby stripping the body portion of ingot 100 from the portion of ingot 100 to be stripped.

It will be appreciated that the body portion of ingot 100 is generally thicker and therefore the body portion of ingot 100 may be directly held by mechanical means or a force may be applied directly to the body portion of ingot 100 by mechanical means.

Of course, if the bulk portion of ingot 100 is thin, the bulk portion of ingot 100 may also be adhered to another solid substrate 500 via tie layer 400 as shown in fig. 9.

In the above steps, the solid substrate 500 and/or the body part of the ingot 100 applies force to make the body part of the ingot 100 and the part of the ingot 100 to be stripped generate relative movement, so that the part of the ingot 100 to be stripped can be stripped from the body part of the ingot 100 to generate wafers, the stripping mode is simple and reliable, the production cost can be reduced, and the production efficiency is improved.

Referring to fig. 3, step 400, reducing the adhesion of the adhesion layer 400, separates the resulting wafer from the solid substrate 500.

The adhesive layer 400 may be an adhesive material layer, such as a thermal release adhesive, a light release adhesive, or a soluble adhesive material, as described above.

Specifically, if the adhesive material layer is a thermal release adhesive, the adhesiveness of the adhesive layer 400 is reduced, and the step of separating the resulting wafer from the solid substrate 500 further includes: heating the adhesive material layer causes the adhesive material layer to lose its adhesiveness, thereby separating the wafer from the solid substrate 500.

If the adhesive material layer is a photo-release adhesive, the adhesiveness of the adhesive layer 400 is reduced, and the step of separating the resulting wafer from the solid substrate 500 further includes: the adhesive material layer is irradiated with light to lose its adhesiveness, thereby separating the wafer from the solid substrate 500.

If the adhesive material layer is a soluble adhesive material, which reduces the adhesion of the adhesive layer 400, the step of separating the resulting wafer from the solid substrate 500 further comprises: and introducing an etching solution 900 into the viscous material layer to dissolve the viscous material layer in the etching solution 900, so that the wafer is separated from the solid substrate 500.

Illustratively, taking a double-sided adhesive tape as an example, a general double-sided adhesive tape may simultaneously have the properties of a thermal release adhesive, a photo release adhesive and a soluble adhesive material.

The first method is to heat the double-sided adhesive tape at high temperature to melt the double-sided adhesive tape and lose or reduce the viscosity of the double-sided adhesive tape. For example, referring to fig. 10, the solid substrate 500 may be heated by the temperature control assembly 700, and the solid substrate 500 may conduct heat to the double-sided adhesive tape, so that the double-sided adhesive tape is melted by the heat. It can be understood that the solid substrate 500 may be made of a material with good thermal conductivity to improve the thermal conductivity.

And in the second method, light irradiation is carried out on the double-sided adhesive tape, so that the double-sided adhesive tape is subjected to photolysis to lose or reduce the viscosity. For example, referring to fig. 11, light may be emitted by a light source 800 (e.g., ultraviolet rays) and may be irradiated on the double-sided adhesive through the solid substrate 500 to photolyze the double-sided adhesive. It can be understood that the solid substrate 500 may be made of a material with high transmittance to improve the illumination effect.

And thirdly, introducing corrosive liquid 900 into the double-sided adhesive tape to dissolve the viscous material layer in the corrosive liquid 900, thereby losing or reducing the viscosity. For example, referring to fig. 12, the solid substrate 500 to which the wafer is attached may be immersed in an etching solution 900, and the etching solution 900 penetrates the double-sided tape through the solid substrate 500 to dissolve the double-sided tape in the etching solution 900.

It can be understood that, at this time, as shown in fig. 12, a plurality of permeation holes 510 connected to the surface close to the viscous material layer may be disposed on the solid substrate 500, and the permeation holes 510 enable the corrosive liquid 900 to permeate to the double-sided adhesive tape more easily, so as to improve the dissolving efficiency of the double-sided adhesive tape.

Furthermore, in some embodiments, the solid substrate 500 may also be made of a soluble material, such as acrylic plate. The solid substrate 500 to which the wafer is attached is immersed in the etching solution 900, and both the acrylic plate and the double-sided tape are dissolved in the etching solution 900, thereby obtaining the wafer, which can further increase the speed of separating the wafer from the solid substrate 500.

In the above-mentioned step, by using some decomposable or soluble viscous material, on the one hand, the portion of ingot 100 to be stripped can be well fixed during the separation of the portion of ingot 100 to be stripped from the body portion of ingot 100; on the other hand, after the portion of ingot 100 to be peeled and the body portion of ingot 100 are separated to produce a wafer, the wafer and solid substrate 500 can be easily separated. It can be seen that the method can improve the efficiency of wafer manufacturing well, and the manufacturing process is simple and reliable.

In addition, the method for manufacturing a wafer of the present application further includes: and grinding the separated surface of the peeled wafer to form a smooth surface.

It should be noted that this step may be performed before the wafer is separated from the solid substrate 500 or after the wafer is separated from the solid substrate 500.

Specifically, the step can smooth the separating surface of the wafer by a grinding device, so that the wafer meets the processing requirement.

The present application is intended to cover any variations, uses, or adaptations of the invention using its general principles and without departing from the spirit or essential characteristics thereof.

Claims

1. A method of manufacturing a wafer for separating an ingot into wafers, the ingot having a C-axis and a C-plane perpendicular to the C-axis, and the ingot further having a first surface parallel to or at an angle to the C-plane, the method comprising the steps of:

2. The method of claim 1, wherein the adhesive layer is a thermal release adhesive, a light release adhesive, or a soluble adhesive material.

3. The method of claim 2, wherein the adhesive material layer is a thermal release adhesive, the adhesive property of the adhesive layer is reduced, and the step of separating the resulting wafer from the solid substrate comprises:

separating the wafer from the solid substrate.

4. The method of claim 2, wherein the adhesive material layer is a light release adhesive, the step of reducing the adhesiveness of the adhesive layer and separating the resulting wafer from the solid substrate comprises:

separating the wafer from the solid substrate.

5. The method of claim 2, wherein the adhesive material layer is a soluble adhesive material, the step of reducing the adhesiveness of the adhesive layer and separating the resulting wafer from the solid substrate comprises:

separating the wafer from the solid substrate.

6. The method for manufacturing a wafer according to claim 2, wherein the step of introducing an etching solution into the viscous material layer to dissolve the viscous material layer in the etching solution and thereby lose the viscosity further comprises:

7. The method of claim 5 or 6, wherein the solid substrate is a soluble material, the step of reducing the adhesion of the bonding layer further comprises the step of separating the resulting wafer from the solid substrate:

8. The method for manufacturing a wafer according to claim 1, wherein the step of forming a peeling layer at a depth position corresponding to the thickness of the wafer from the first surface in the ingot by irradiation of the laser light further comprises:

9. The method for manufacturing a wafer according to claim 1, wherein the step of forming a peeling layer at a depth position corresponding to the thickness of the wafer from the first surface in the ingot by irradiation of the laser light further comprises:

10. A method for fabricating a wafer as recited in any one of claims 1 to 9, further comprising: and grinding the separated surface of the peeled wafer to form a smooth surface.