JP2024118347A - Wafer manufacturing method - Google Patents

Abstract

[Problem] To provide a method for manufacturing a wafer, which can produce a wafer with small warpage and good nanotopography even when grinding a resin-laminated wafer. [Solution] The method for manufacturing a wafer includes a preparation step of preparing a raw material wafer having a first main surface and a second main surface and having processing distortion on the surface, an etching step of removing the processing distortion of the raw material wafer by etching the first main surface and the second main surface of the raw material wafer, a resin layer formation step of forming a planarizing resin layer on the second main surface of the raw material wafer subsequent to the etching step, a first processing step of grinding or polishing the first main surface of the raw material wafer while adsorbing and holding the surface of the planarizing resin layer on a holding surface as a reference surface, a removal step of removing the planarizing resin layer from the raw material wafer, and a second processing step of grinding or polishing the second main surface of the raw material wafer while adsorbing and holding the first main surface of the raw material wafer, from which the planarizing resin layer has been removed, on a holding surface. [Selected Figure] Figure 2

Description

The present invention relates to a method for manufacturing a wafer.

Conventionally, semiconductor wafers require flattening of their surfaces in order to create fine patterns using photolithography. In particular, technology has been proposed to improve the flatness of semiconductor wafers by reducing surface waviness, known as nanotopography.

Patent Document 1 discloses a method for manufacturing semiconductor wafers, which includes a primary etching step in which the semiconductor wafer after lapping is etched with a primary etching solution, a surface grinding step in which the surface of the semiconductor wafer is ground with a grinding wheel after the primary etching step, a secondary etching step in which the surface-ground semiconductor wafer is etched lighter than in the primary etching step with a secondary etching solution, and a mirror polishing step in which the surface of the semiconductor wafer is mirror-polished with an abrasive cloth after the secondary etching step.

The manufacturing method described in Patent Document 1 uses this process to remove processing damage that occurs during surface grinding by lightly secondary etching the wafer, which further reduces the amount of wafer polishing in the mirror polishing process, further reducing the total thickness variation (TTV) and improving wafer flatness.

As a method for producing a wafer with good nanotopography, a method of grinding a resin-coated wafer, as disclosed in Patent Document 2, is known. Specifically, in the primary grinding process, both sides (first side and second side) of a wafer obtained by cutting from an ingot are ground to remove processing distortions on both sides and reduce warping caused by differences in the magnitude of the processing distortions.

Next, in the resin application process, wavy shape restoration process, and resin hardening process, the wavy shape of the surface layer on both sides of the wafer is maintained while being shaped and hardened with ultraviolet-curable resin. After that, in the first-side and second-side wavy removal processes, the wavy shape that has developed on the surface layer of the wafer that has been hardened with ultraviolet-curable resin is removed. In this way, in Patent Document 2, a wafer with good nanotopography is produced by applying resin to the wafer and grinding it.

JP 2003-045836 A JP 2011-249652 A

In a technique such as that in Patent Document 1, which reduces damage by etching and then grinds, the wafer is lightly secondary etched to remove processing damage that occurs during surface grinding, and the amount of wafer polishing in the mirror polishing process is reduced, thereby improving wafer flatness (preventing deterioration of the shape due to polishing), but the waviness is not sufficiently improved and the nanotopography is insufficient. To improve this, a technique such as that in Patent Document 2, which combines resin pasting and grinding, was effective.

In Patent Document 2, by grinding the wafer before applying resin, it is possible to make the front and back surfaces have similar processing distortion to a certain extent, but depending on the condition of the grinding equipment and wheels, the processing distortion on the front and back surfaces may not be equivalent. Also, it was found that in the case of a Si single crystal wafer with a (111) surface orientation, the front and back surfaces do not have equivalent grinding distortion after grinding.

In this way, the grinding process may not result in equivalent processing strain on the front and back sides, and it was found that in particular with Si single crystal wafers with a (111) surface orientation, the grinding strain on the front and back sides is not equivalent.

As described above, when the processing strain differs between the front and back surfaces of a wafer, warping occurs due to the difference in processing strain. For this reason, it was found that when wafers with different processing strains between the front and back surfaces are used, the resin is applied to the wafer in a warped state, resulting in worsening warping after grinding.

The present invention has been made to solve the above problems, and relates to a semiconductor wafer processing process, in particular, a processing process for highly planarizing the surface of a semiconductor wafer, and relates to a technology for simultaneously improving nanotopography and warp.

More specifically, the present invention aims to provide a wafer manufacturing method that can produce wafers with little warpage and good nanotopography, even when grinding resin-laminated wafers.

The present invention has been made to achieve the above object, and provides a method for manufacturing a wafer, comprising the steps of: preparing a raw material wafer having a first main surface and a second main surface opposite to the first main surface and having processing strain on the surface; etching a raw material wafer by etching the first main surface and the second main surface to remove the processing strain of the raw material wafer; forming a resin layer on the second main surface of the raw material wafer following the etching; a first processing step of grinding or polishing the first main surface of the raw material wafer by adsorbing the surface of the planarizing resin layer onto a holding surface as a reference surface; removing the planarizing resin layer from the raw material wafer; and a second processing step of grinding or polishing the second main surface of the raw material wafer by adsorbing the first main surface of the raw material wafer by the holding surface, with the first main surface having the planarizing resin layer removed.

According to such a wafer manufacturing method, the front and back surfaces of the wafer are etched immediately before resin application in order to remove processing strain on the front and back surfaces. More specifically, by etching the first and second main surfaces of the raw material wafer before resin application, processing strain from the previous step is removed, and the wafer from which warpage caused by the difference in processing strain between the first and second main surfaces of the raw material wafer is removed is subjected to subsequent resin application to the second main surface, which is then cured, and grinding is performed.
Therefore, even when grinding a resin-laminated wafer, it is possible to produce a wafer with little warping and good nanotopography.

In this case, the raw wafers can be wafers obtained by slicing an ingot.

As a result, the processing distortion formed in the wafer when the ingot was sliced is removed by etching, so even if the wafer sliced from the ingot is subsequently bonded to a resin and ground, it is possible to produce a wafer with little warping and good nanotopography.

In this case, the raw wafers can be sliced wafers obtained by cutting from an ingot and then lapping or grinding both sides of the sliced wafers.

As a result, processing distortions formed in the wafer during double-sided lapping or grinding are removed by etching, so that even when a wafer that has been double-sided lapping or grinding is subsequently bonded with resin and then ground, it is possible to produce a wafer with little warping and good nanotopography.
Furthermore, by performing double-sided lapping or double-sided grinding, even if the waviness of the wafer after slicing is large, the waviness of the wafer can be reduced, and wafers with good nanotopography can be manufactured.

As described above, the wafer manufacturing method of the present invention makes it possible to manufacture wafers with little warping and good nanotopography, even when grinding resin-laminated wafers.

1A to 1C are schematic diagrams showing an example of an outline of a method for producing a wafer according to the present invention. 1 is a flow diagram showing an outline of an example of a method for producing a wafer according to the present invention.

The present invention is described in detail below, but is not limited to these.

As mentioned above, there was a need for a wafer manufacturing method that could produce wafers with minimal warpage and good nanotopography, even when grinding resin-bonded wafers.

As a result of intensive research into the above-mentioned problem, the inventors have discovered a method for manufacturing a wafer, comprising: a preparation step of preparing a raw material wafer having a first main surface and a second main surface opposite to the first main surface, the raw material wafer having processing strain on the surface; an etching step of removing the processing strain of the raw material wafer by etching the first main surface and the second main surface of the raw material wafer; a resin layer formation step of forming a planarized resin layer on the second main surface of the raw material wafer following the etching step; and a step of adsorbing and holding the surface of the planarized resin layer on a holding surface as a reference surface, and in that state, The present invention has been completed by discovering that a wafer manufacturing method including a first processing step of grinding or polishing the first main surface of a raw material wafer, a removal step of removing the planarizing resin layer from the raw material wafer, and a second processing step of adsorbing and holding the first main surface of the raw material wafer from which the planarizing resin layer has been removed, processed in the first processing step, on the holding surface, and grinding or polishing the second main surface of the raw material wafer in this state, can produce wafers with little warping and good nanotopography even when grinding a resin-laminated wafer.

The wafer manufacturing method according to an embodiment of the present invention will be described below with reference to Figures 1 and 2.

First, as shown in FIG. 1(a), a raw material wafer 100 having a first main surface 1 and a second main surface 2 opposite to the first main surface 1 and having processing damage on the surface is prepared (S1 in FIG. 2, preparation step).
The composition, crystal structure, and the like of the raw material wafer 100 are not particularly limited, but an example thereof is a Si single crystal wafer.

In particular, Si single crystal wafers with the first main surface 1 and second main surface 2 oriented in the (111) plane are prone to warping because it is difficult to make the processing strain of the first main surface 1 and the second main surface 2 equivalent by machining such as grinding alone, and this is preferable because the warping suppression effect of the present invention is more pronounced.

The diameter and thickness of the raw material wafer 100 are not particularly limited and may be selected appropriately within the range that allows for manufacturing and processing.

The raw material wafer 100 has processing damage on its surface.
Such raw wafer 100 may be a wafer obtained by slicing an ingot.
This is because such wafers are subject to processing strain when sliced from an ingot.

The raw wafer 100 may be a sliced wafer obtained by cutting from an ingot and then performing double-sided lapping or double-sided grinding. In other words, the sliced wafer may be subjected to lapping or double-sided grinding. This is because lapping or double-sided grinding also causes processing distortion in the wafer. Also, even if the waviness after slicing is large, the waviness can be reduced by lapping or double-sided grinding.

After preparing the raw material wafer 100, the first main surface 1 and the second main surface 2 of the raw material wafer 100 are etched to remove processing damage to the raw material wafer 100 (S2 in FIG. 2, the etching process, also called pre-resin application etching).

Regarding the etching conditions, since the purpose is to remove processing distortion from previous processing, the etching method can be either wet etching or dry etching. Furthermore, the etching equipment can be either single-wafer or batch type. Furthermore, the composition of the etchant is not important.

The etching conditions of the present invention may be any conditions that can dissolve and remove the mechanically damaged (distorted) layer that occurs during previous processes such as slicing, lapping, and grinding (particularly before resin application), and conditions for etching the surface of bare silicon that is carried out during the processing of single crystal silicon wafers can be adopted.

Specifically, wet etching is a chemical reaction that uses an acidic or alkaline etching solution; for example, NaOH, KOH, or an acidic mixture of hydrofluoric acid, nitric acid, and acetic acid can be used as etchants. In addition, the bare silicon surface can also be etched by dry etching using high vacuum plasma, which dissolves and removes the damaged (distorted) layer of silicon. Processing conditions are set appropriately depending on the wafer condition (depth of the damaged layer) from previous processes, etc.

In the case of wet etching, etching can be performed by immersing the raw wafer 100 in an etchant 7 as shown in FIG. 1(b). The etching temperature and etching time can also be appropriately selected within a range in which processing distortion can be removed by etching within the working time available for etching.

When using sliced wafers as the raw wafer 100, if there is a large waviness after slicing, lapping or double-sided grinding may be performed before the resin application etching to reduce the waviness.

However, even if lapping or double-head grinding is performed, the processing distortion on the front and back surfaces (second main surface 2 and first main surface 1) of the raw material wafer 100 may differ after lapping or double-head grinding, so it is necessary to remove the warpage caused by the processing distortion by performing etching before applying the resin.

After the etching is completed, a planarizing resin layer 15 is subsequently formed on the second main surface 2 of the raw material wafer 100 (S3 in FIG. 2, a resin layer forming step, also referred to as resin lamination).
Specifically, the resin is applied in the following procedure, to form the flattening resin layer 15 .

(Resin application conditions)
First, as shown in FIG. 1(c), a light-transmitting film 11 such as PET (polyethylene terephthalate) is laid on a platen (lower platen 9) having a flat surface, and a resin 13 in a plastic state, for example a liquid state, is supplied and applied thereon. Furthermore, a raw material wafer 100 is placed on the resin 13 so that the second main surface 2 is in contact with the resin 13, and a platen (upper platen) (not shown) is used to bring the lower surface of the upper platen into contact with the first main surface 1 of the raw material wafer 100 so that the surface of the film 11 is flat, and the upper platen is pressed against the lower platen 9 with a predetermined load (S3-1 in FIG. 2, resin application step). Note that the waviness of the first main surface 1 and the second main surface 2 is also pressed and flattened by the pressing.

When the surface of the film 11 becomes flat, the pressure is released by, for example, pulling the upper platen (not shown) away from the raw material wafer 100 as shown in FIG. 1(d) (S3-2 in FIG. 2, undulation shape recovery process). By releasing the pressure, the undulations of the first main surface 1 and the second main surface 2 return to the shape they were in before the pressure was applied.

After that, a curing process is performed according to the type of resin 13 used (S3-3 in FIG. 2, resin curing process). For example, when a UV (ultraviolet) curable resin is used as the resin 13, the resin 13 is cured by irradiating it with UV light from a UV light source 17 as shown in FIG. 1(e). This causes the resin 13 to be attached to the second main surface 2, forming a planarizing resin layer 15. Here, an example is shown in which the planarizing resin layer 15 is formed from the resin 13 and the film 11, but if the film 11 is not used, the planarizing resin layer 15 is formed from the resin 13 alone.

The etching step S2 and the resin layer forming step S3 are performed consecutively. In other words, no other steps such as machining the raw material wafer 100 are performed between the etching step S2 and the resin layer forming step S3. By performing the etching step S2 and the resin layer forming step S3 consecutively, the planarized resin layer 15 can be formed with the processing distortions removed by etching, and warping can be reliably suppressed.

Once the resin application is complete, the surface of the planarizing resin layer 15 is used as a reference surface and is adsorbed and held on the holding surface 19, and in this state, the first main surface 1 of the raw material wafer 100 is ground or polished (S4 in Figure 2, first processing step).

Specifically, first, as shown in FIG. 1(f), the raw material wafer 100 is placed on a chuck table 21 having a holding surface 19 of a grinding or polishing device so that the planarizing resin layer 15 is in contact with the chuck table 21. The chuck table 21 is made of, for example, porous ceramic, and holds the raw material wafer 100 by vacuum adsorbing the planarizing resin layer 15.

Next, the grinding wheel of the grinding device or the polishing pad of the polishing device is rotated and pressed against the first main surface 1 to grind or polish the first main surface 1 and remove the waviness. Figure 1(f) shows an example of grinding the first main surface 1 using the grinding wheel 23 of the grinding device.

When the first processing step S4 is completed, the planarization resin layer 15 is removed from the raw material wafer 100 as shown in FIG. 1(g) (S5 in FIG. 2, removal step). Specifically, the planarization resin layer 15 attached to the second main surface 2 of the raw material wafer 100 is peeled off from the raw material wafer 100.

Next, as shown in FIG. 1(h), the first main surface 1 processed in the first processing step S4 of the raw material wafer 100 from which the planarizing resin layer 15 has been removed is adsorbed and held on the holding surface 19, and in this state, the second main surface 2 of the raw material wafer 100 is ground or polished (S6 in FIG. 2, second processing step). This removes waviness in the second main surface 2.

The conditions for grinding or polishing the second main surface 2 in the second processing step S6 are the same as the conditions for grinding or polishing the first main surface 1 in the first processing step S4. Note that steps S3 to S6 are sometimes collectively referred to as resin application grinding.

Through the above steps, wafers are manufactured from the raw wafer 100, with processing distortions and waviness removed. The manufactured wafers may be further polished on both sides using a double-sided polishing machine to further smooth the surface.

In this way, in the present invention, by removing the processing distortion of the raw material wafer 100 by etching before forming the planarized resin layer 15 by resin lamination, the resin lamination can be performed in a state where deformation due to the difference in processing distortion between the first main surface 1 and the second main surface 2 is removed, so that not only nanotopology but also warping can be improved.

The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.
A comparison was made between a case where a wafer was manufactured by performing etching before forming the flattening resin layer 15 based on the wafer manufacturing method of the present invention and a case where a wafer was manufactured by forming the flattening resin layer 15 without performing etching based on the wafer manufacturing method of the prior art in terms of warp and nanotopology (NT). The specific procedure is as follows.

(Example 1-1)
First, in the preparation step S1, a raw material wafer 100 was prepared, which was a P-type Si single crystal having a diameter of 300 mm that had been sliced and then chamfered, and in which the first main surface 1 and the second main surface 2 had a (100) plane orientation.

Next, the raw wafer 100 was subjected to pre-resin coating etching as the etching process S2. Specifically, the wafer was immersed in a high-temperature aqueous sodium hydroxide solution as the etchant 7 to remove processing strain on the first main surface 1 and the second main surface 2.

Next, resin coating and grinding (steps S3 to S6 in FIG. 2) were performed in the following manner.
First, the planarizing resin layer 15 was formed on the raw material wafer 100 after the etching step S2 in the following procedure as the resin layer forming step S3.
Specifically, first, a UV-curable resin was prepared as the resin 13 for covering the raw wafer 100 , and a PET film was prepared as the film 11 .

Next, in the resin application step S3-1, a PET film was laid on a flat glass surface plate (lower surface plate 9), and 10 ml of a UV-curable resin was dropped onto the PET film.
Thereafter, the first main surface 1 of the raw material wafer 100 was held by suction on a ceramic surface plate (upper surface plate), and the second main surface 2 side was pressed against and bonded to a UV-curable resin.

The pressing force was controlled by driving a servo motor that holds a ceramic surface plate and applying pressure until a predetermined load was detected such that the film 11 became flat.
Thereafter, in a wavy shape recovery step S3-2, the pressure was released, and in a resin hardening step S3-3, the resin 13 was irradiated with UV light using a UV-LED having a wavelength of 365 nm as the UV light source 17 for hardening the resin, thereby hardening the resin.

Next, a first processing step S4 was carried out in the following manner, and the first main surface 1 of the raw material wafer 100 was ground.
Specifically, for the grinding process, a grinding wheel 23 bonded with diamond abrasive grains was used, and the axis angle of the chuck table 21 of the grinding device was adjusted so that the wafer thickness variation was 1 μm or less.

In this state, the second main surface 2 side, which is the side on which the flattening resin layer 15 is formed, is vacuum-adsorbed onto the chuck table 21, and the first main surface 1 side is ground using a grinding wheel 23.

Then, in a removal step S5, the planarizing resin layer 15 was peeled off, and in a second processing step S6, the first main surface 1 side was vacuum-adsorbed onto the chuck table 21, and the second main surface 2 side was ground.

The removal amount for the resin coating grinding process was set to the amount necessary to remove the irregularities on the wafer surface that formed when the resin was applied, and to the conditions and removal amount to achieve the required wafer thickness.

Finally, as a mirror polishing process, the first main surface 1 and the second main surface 2 were mirror-polished using a known double-sided polishing device.
In this manner, in Example 1-1, the grinding process before resin application was not performed, but the etching process before resin application and the grinding process after resin application were performed.

(Example 1-2)
A wafer was manufactured under the same conditions as in Example 1-1, except that the raw wafer 100 was subjected to a grinding process (grinding before resin application) under the following conditions before performing the etching step S2.
Specifically, a grinding wheel 23 bonded with diamond abrasive grains was used, and the axis angle of the chuck table 21 of the grinding device was adjusted so that the wafer thickness variation was 1 μm or less, the second main surface 2 side was vacuum-adsorbed to the chuck table 21, and the first main surface 1 side was ground with the grinding wheel 23. Furthermore, the first main surface 1 side was vacuum-adsorbed to the chuck table 21 of the grinding device, and the second main surface 2 side was ground with the grinding wheel 23. That is, in Example 1-2, grinding before resin application, etching before resin application, and resin application grinding were performed.

Grinding before resin application was performed in the previous process, particularly to improve waviness and thickness variation of the wafer after slicing, and processing was performed under conditions and with a removal allowance that would result in wafer thickness variation of 1 μm or less.

(Comparative Example 1-1)
Wafers were manufactured under the same conditions as in Example 1-2, except that the resin coating and grinding process was carried out without carrying out the pre-resin coating grinding and without carrying out the pre-resin coating etching.
The resin coating and grinding process was carried out under the same conditions as in Example 1-2.

(Comparative Example 1-2)
Wafers were manufactured under the same conditions as in Example 1-2, except that etching before resin application was not performed. Specifically, grinding before resin application was performed, and resin application grinding processing was performed.
The grinding before resin application and the grinding after resin application were carried out in the same manner as in Example 1-2.

(Example 2-1)
Wafers were manufactured under the same conditions as in Example 1-1, except that a wafer of P-type Si single crystal having a diameter of 300 mm, which was sliced and then chamfered, and in which the first main surface 1 and the second main surface 2 had a (111) plane orientation, was prepared as the raw material wafer 100.

(Example 2-2)
Wafers were manufactured under the same conditions as in Example 1-2, except that a P-type Si single crystal (111) wafer having a diameter of 300 mm that had been sliced and then chamfered was prepared as the raw wafer 100 .

(Comparative Example 2-1)
A wafer was manufactured under the same conditions as in Comparative Example 1-1, except that a P-type Si single crystal (111) wafer having a diameter of 300 mm that had been sliced and then chamfered was prepared as the raw wafer 100 .

(Comparative Example 2-2)
Wafers were manufactured under the same conditions as in Comparative Example 1-2, except that a P-type Si single crystal (111) wafer having a diameter of 300 mm that had been sliced and then chamfered was prepared as the raw wafer 100 .

[Measurement results]
Warp and nanotopography (NT) were measured for the wafers of Examples 1-1, 1-2, 2-1, and 2-2 and Comparative Examples 1-1, 1-2, 2-1, and 2-2. Specifically, an optical interference type flatness/nanotopography measuring device (KLA Corporation: WaferSight2+) was used, and an SQMM 10 mm x 10 mm was used as an index of nanotopography.

Warp was checked by observing the change in value when the resin was applied and ground after it had been ground from the state before the resin was applied (before the resin was applied). Those that worsened (worsened by 2.5 μm or more) were marked with an X, those that remained unchanged (less than 2.5 μm) were marked with a △, and those that improved (value became smaller) were marked with an O. NT was rated as O: less than 5 nm, △: 5 nm to less than 10 nm, and X: 10 nm or more.

The wafer manufacturing conditions and the evaluation results for Warp and NT are shown in Table 1.

In Comparative Example 1-1, the nanotopography was good, but the warp deteriorated after the resin coating and grinding process. This is thought to be because the processing distortion during the slicing process was different between the first main surface 1 and the second main surface 2, and as a result, the resin coating and grinding process was performed on a warped wafer.

In Comparative Example 1-2, the warp was improved compared to Comparative Example 1-1, but the resin coating and grinding process did not improve the warp. This is thought to be because, although grinding before resin coating was able to reduce the processing distortion in the slicing process, it was not possible to make it equivalent.

In Example 1-1, both the warp and nanotopography were good. This is thought to be because the processing distortion during the slicing process was removed by etching before the resin application, and the resin application grinding process could be performed without warping caused by the difference in processing distortion between the first main surface 1 and the second main surface 2.

In Example 1-2, both the warp and nanotopography were good. This is thought to be because the processing distortion caused by grinding before resin application was removed by etching before resin application, and the resin application grinding process could be performed without warping caused by the difference in processing distortion between the first main surface 1 and the second main surface 2.

In Comparative Example 2-1, the nanotopography was good, but the warp deteriorated after the resin coating and grinding process. This is thought to be because the processing distortion during the slicing process was different between the first main surface 1 and the second main surface 2, and as a result, the resin coating and grinding process was performed on a warped wafer.

In Comparative Example 2-2, the nanotopography was good, but the warp deteriorated after the resin application grinding process. This is thought to be because in a Si single crystal wafer with a (111) surface orientation, the processing distortion caused by the grinding process could not be made equivalent on the first principal surface 1 and the second principal surface 2.

In Example 2-1, both the warp and nanotopography were good. This is thought to be because the processing distortion during the slicing process was removed by etching before the resin application, and the resin application grinding process could be performed without warping caused by the difference in processing distortion between the first main surface 1 and the second main surface 2.

In Example 2-2, both the warp and nanotopography were good. This is thought to be because the processing distortion caused by grinding before resin application was removed by etching before resin application, and the resin application grinding process could be performed without warping caused by the difference in processing distortion between the first main surface 1 and the second main surface 2.

From the above results, it was found that good warps and good nanotopography could be obtained by performing etching before resin application and then performing resin application and grinding (S3 to S6).
In other words, it was found that by using the wafer manufacturing method of the present invention, wafers with good warp and good nanotopography can be manufactured.

The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included within the technical scope of the present invention.

1...first main surface, 2...second main surface, 7...etchant, 9...lower surface plate, 11...film, 13...resin, 15...flattening resin layer, 17...UV light source, 19...holding surface, 21...chuck table, 23...wheel, 100...raw material wafer.

Claims (3)

A method for manufacturing a wafer, comprising the steps of:
A preparation step of preparing a raw material wafer having a first main surface and a second main surface opposite to the first main surface, the raw material wafer having processing strain on the surface;
an etching step of removing the processing damage of the raw material wafer by etching the first main surface and the second main surface of the raw material wafer;
a resin layer forming step of forming a planarizing resin layer on the second main surface of the raw material wafer subsequent to the etching step;
a first processing step of adsorbing and holding the raw material wafer on a holding surface using a surface of the planarizing resin layer as a reference surface, and grinding or polishing the first main surface of the raw material wafer in that state;
a removing step of removing the planarizing resin layer from the raw material wafer;
A wafer manufacturing method characterized by including a second processing step of adsorbing and holding the first main surface of the raw material wafer from which the planarizing resin layer has been removed, the first main surface having been processed in the first processing step, on a holding surface, and in that state, grinding or polishing the second main surface of the raw material wafer. The method for manufacturing a wafer according to claim 1, characterized in that the raw wafer is a wafer obtained by slicing an ingot. The method for manufacturing a wafer according to claim 1, characterized in that the raw wafer is a sliced wafer obtained by cutting from an ingot and then performing double-sided lapping or double-sided grinding.

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