KR20200009420A - Substrate for semiconductor and making method - Google Patents

Abstract

The present invention provides a substrate for a semiconductor which has no deformation or less deformation even when film formation or high temperature heating treatment is performed, and a method for manufacturing the same. The substrate for a semiconductor comprises one side having a convex shaped SORI and the other side having a concave shaped SORI whose degree is the same as the SORI of the one side, and thickness change of the substrate is less than or equal to 3 um.

Description

Substrate for semiconductor and its manufacturing method {SUBSTRATE FOR SEMICONDUCTOR AND MAKING METHOD}

The present invention relates to a semiconductor substrate and a method of manufacturing the same.

BACKGROUND ART In semiconductor integrated circuits (LSI: Large Scale Integration) and TFT-LCD (Thin Film Transistor-Liquid Crystal Display), the demand for miniaturization and high-speed operation is increasing, and films formed on semiconductor substrates are becoming more dense.

When the flatness of the polysilicon TFT is impaired, problems such as being unable to be adsorbed or gripped when the glass wafer is chucked or the robot is conveyed in the liquid crystal display device manufacturing process may occur, or polysilicon may occur. In the photolithography step of performing a fine pattern in the process of forming a TFT, problems such as deterioration of pattern overlap or the like arise.

Moreover, in the liquid crystal panel, if the flatness of two transparent glass bodies does not match, the film thickness of the liquid crystal inserted in it will become difficult to become uniform, color nonuniformity etc. will arise and a quality problem will also arise.

In addition, when manufacturing a TFT-LCD using a polysilicon thin film, since a processing temperature reaches 1000 degreeC or more, a board | substrate produces a viscous deformation and a bending deformation arises.

In order to solve these problems, for example, Patent Document 1 proposes a method of providing an active element substrate containing a quartz glass material which is excellent in heat resistance and high purity by suppressing the content of hydroxyl group concentration and chlorine concentration. have.

Moreover, in patent document 2, by forming a silicon nitride film in the front and back of a board | substrate, the method of canceling the stress of a silicon nitride film in the front and back of a board | substrate, and not causing curvature of a board | substrate is proposed.

Moreover, in patent document 3, the density change by virtual temperature is made small by using quartz glass which makes fluorine concentration into a fixed range, and does not contain an alkali metal oxide substantially, and is excellent in the dimensional stability before and after high temperature treatment. A method of obtaining a quartz glass substrate for a TFT LCD is disclosed.

Japanese Patent Laid-Open No. 6-11705 Japanese Patent Laid-Open No. 11-121760 Japanese Patent Laid-Open No. 2005-215319

However, in the method of patent document 1, even if the flatness of a quartz glass material is improved, the deformation | transformation by the film stress of a subsequent polysilicon thin film cannot be suppressed.

Moreover, in the method of patent document 2, unless the same film | membrane is comprised in the front and back surface of a board | substrate, generation | occurrence | production of a curvature cannot be eliminated, but since it is not common that both sides of a TFT side and a color filter side are comprised by the same film | membrane, It is difficult to suppress deformation even in this way.

Moreover, also in the method of patent document 3, although the dimensional stability before and behind high temperature treatment is excellent, it is not possible to suppress the deformation | transformation by film stress.

This invention is made | formed in view of the said situation, and an object of this invention is to provide the semiconductor substrate which has no deformation | transformation or little deformation, and its manufacturing method, even when film-forming and high temperature heat processing are performed.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to achieve the said objective, the present inventors used a manufacturing apparatus, such as a double-sided wrap apparatus, a single-sided wrap apparatus, a double-sided polishing apparatus, or a single-side polishing apparatus normally used in manufacture of a semiconductor substrate, and has low cost and reproducibility. It is satisfactory that SORI and BOW can be arbitrarily controlled, and that a semiconductor substrate having a small thickness variation can be produced. More specifically, the semiconductor substrate is deformed by film stress or high temperature heat treatment by the above apparatus. On the premise of this, in consideration of the amount of deformation in advance, a deliberately-shaped substrate is produced in the opposite direction to these deformations, so that even when film formation or high temperature heat treatment are performed, a substrate for semiconductors having no deformation or less deformation is produced. It was found that it was obtained, and completed this invention.

That is, the present invention,

1. A semiconductor substrate comprising one surface having a convex SORI and the other surface having a concave SORI having the same degree as the SORI, and having a thickness variation of 3 μm or less,

2. The substrate for semiconductors of 1 whose SORI of each said surface is 50-600 micrometers,

3. The board | substrate for semiconductors of 1 or 2 whose BOW of one surface which has said convex SORI is + 25- + 300,

4. The substrate for semiconductors according to any one of 1 to 3, wherein the BOW of the other side having the concave SORI is -25 to -300;

5. Substrate for semiconductors in any one of 1 to 4 having a thickness of 0.5 to 3 mm,

6. The semiconductor substrate according to any one of 1 to 5, wherein the shape of the semiconductor substrate is a planar circular shape having a diameter of 100 to 450 mm or a rectangular shape having a diagonal length of 100 to 450 mm,

7. Substrate for semiconductors in any one of 1-6 which is made of synthetic quartz glass,

8. Substrate for semiconductors in any one of 1 to 7 which is a substrate for polysilicon TFT,

9. A transfer disc having a surface and a back surface, passing through a midpoint on a center line connecting the center points of the front and back surfaces, and having a thickness variation and SORI in which the surface and back surfaces face symmetrically with respect to a plane perpendicular to the center line. And a two raw material substrates are installed in the double-sided wrap apparatus so as to sandwich the transfer disc, and the surface which does not come into contact with the transfer disc in the respective raw material substrates is processed. The shape of the transfer disc is transferred by a transfer step of producing two transfer substrates on which the shape of the used disc is transferred onto one side, and by wrapping both surfaces of the transfer substrate, or in the transfer step on the transfer substrate. A lapping step of manufacturing a lapping substrate by lapping only the unconverted surface, and both sides or one side of the lapping substrate are polished. Method of manufacturing a substrate,

10. One of the front and back surfaces is parallel to the surface perpendicular to the center line having a surface and a back surface, passing through the midpoint on the center line connecting the center points of the front and back surfaces, and further including the raw material in the front and back surfaces. The raw material substrate is brought into contact with the other surface of the substrate for preparing the transfer disk which is perpendicular to the center line and symmetrical with respect to the center line, and in contact with the other surface of the transfer disk. A transfer step of providing a transfer substrate provided in a single-sided wrap apparatus and processing a surface which is not in contact with the transfer disc in the raw material substrate to transfer the shape of the transfer disc to a single side; and both sides of the transfer substrate By lapping or by wrapping only the surface on which the shape of the transfer disc is not transferred in the transfer step of the transfer substrate. And a lapping step of manufacturing a lamination step and polishing both surfaces or one side of the lapping substrate.

To provide.

According to the present invention, it is possible to provide a semiconductor substrate having a predetermined SORI and thickness variation in consideration of deformation of the semiconductor substrate due to film stress or high temperature heat treatment in advance. For this reason, even when film-forming and high temperature heat processing are performed after that, the board | substrate for semiconductors of a desired shape is obtained.

In addition, the semiconductor substrate of the present invention can be produced with good reproducibility at low cost by using a double-sided wrap apparatus, a single-sided wrap apparatus, or a double-side polishing apparatus or a single-side polishing apparatus that is usually used in the manufacture of a semiconductor substrate.

Fig. 1 shows an aspect of SORI of a semiconductor substrate of the present invention, (A) shows a state in which the convex shape is convex in the Y-axis direction from the center, and (B) shows the state of being convex in the convex shape. (B) shows the state of C in the convex shape which is linear symmetry. In addition, the curve inside the plane shows a contour line representing the height.
Fig. 2 is an explanatory view of SORI of the semiconductor substrate of the present invention, where S represents a least square plane, a is the minimum value of the distance between the surface S and the surface of the semiconductor substrate A, and b is the surface (S). ) And the maximum value of the distance of the surface of the semiconductor substrate A are shown.
Fig. 3 is an explanatory view of a BOW of the semiconductor substrate of the present invention, where e represents the front and back intermediate planes, S2 represents the reference plane obtained from e, f represents the substrate centerline, and the distance between S2 and e intersecting f. In this case, B is defined as + d if e is higher than S2 and -d if lower than S2 as -d.
It is a figure which shows the thickness variation c of the semiconductor substrate of this invention.
It is a schematic diagram which shows the transfer process using the double-sided wrap apparatus which concerns on 1st Embodiment of this invention.
FIG. 6 is a side view showing a transfer disk having SORI that is central symmetry used in the first embodiment. FIG.
It is a schematic diagram which shows the lapping process using the double-sided wrapping apparatus which concerns on 1st Embodiment.
It is a schematic diagram which shows the transfer process using the single-sided wrap apparatus which concerns on 2nd Embodiment of this invention.
FIG. 9 is a side view showing a transfer disk having SORI which is central symmetry used in the second embodiment. FIG.
It is a schematic diagram which shows the lapping process using the single-sided wrapping apparatus which concerns on 2nd Embodiment.
It is a side view which shows the transfer disk which has SORI which is not center symmetry concerning the modification of 1st Embodiment.
It is a side view which shows the transfer disk which has SORI which is not central symmetry concerning the modification of 2nd Embodiment.
FIG. 13 is a top view and a side view showing a transfer disk according to another modification of the first embodiment. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated concretely.

The substrate for semiconductors which concerns on this invention is equipped with one surface which has convex SORI, and the other surface which has concave SORI of the same degree as this SORI, and thickness fluctuation is 3 micrometers or less, It is characterized by the above-mentioned. do.

In this way, by intentionally manufacturing the semiconductor substrate for the shape of the wafer in the opposite direction to the deformation occurring after the film formation or the high temperature heat treatment, before the film formation or the high temperature heat treatment, the desired device is used in the step of making the device or the step of assembling. The semiconductor substrate of the shape can be obtained. Specifically, when it changes convexly by a film-forming or a high temperature heating process, the semiconductor substrate of the shape of a semiconductor wafer is manufactured in the same concave shape, and when it changes concavely, it is convex in advance.

The SORI in the semiconductor substrate of the present invention is not particularly limited as long as the finally obtained semiconductor substrate can be formed in a desired shape, but from the viewpoint of handling, it is preferably 50 to 600 µm, more preferably 100 To 400 µm, still more preferably 100 to 200 µm.

It does not specifically limit as an aspect of SORI in this invention, For example, when a semiconductor substrate deform | transforms into convex shape by center symmetry by a film-forming or a high temperature heating process, it is a center symmetry concave board | substrate. If the semiconductor substrate is convex and the center of the vertex is deformed into a convex shape that is shifted in the Y-axis direction, the concave semiconductor substrate is manufactured according to the misalignment. If the semiconductor substrate is deformed into a line symmetrical convex shape with respect to the line passing through the center (see FIG. 1B), a concave semiconductor substrate with linear symmetry may be produced (FIG. 1). (C)).

Here, SORI in the present invention is the minimum value (absolute value) a and the minimum value (absolute value) of the distance between the least square plane S and the surface of the semiconductor substrate A as shown in FIG. sum of b) (SORI = | a | + | b |)

In addition, when the substrate surface sufficiently reflects light and an interference fringe with the device reference surface is obtained, SORI can be measured using an optical interference flatness tester. Conversely, when the substrate surface is rough and no interference fringes are obtained, SORI can be obtained by scanning the laser displacement meter to sandwich the front and back of the substrate.

On the other hand, in the semiconductor substrate of the present invention, the thickness variation (TTV) is 3 µm or less, preferably 2 µm or less, more preferably in consideration of facilitating focusing during exposure and making the pattern thickness constant. It is 1 micrometer or less.

Here, the thickness variation means a value C obtained by subtracting the thickness of the thinnest portion from the thickness of the thickest portion in the plane of the substrate A, as shown in FIG. 4. In addition, thickness variation can be measured similarly to SORI using an optical interference flatness tester or a laser displacement meter.

Moreover, it is preferable that the BOW of one surface which has the said convex SORI is + 25- + 300, and, as for the board | substrate for semiconductors of this invention, the BOW of the other surface which has said concave SORI is -25. It is preferable that it is from -300.

In the present invention, the BOW is defined as a numerical value of the difference between the center of the substrate surface and the height of the least square mean plane obtained as the surface reference, and the plus sign when the upper side is above the reference plane, and the negative sign when the lower side is the lower side. do. This makes it possible to determine whether the shape of the substrate is convex or concave at least in the center of the substrate.

When SORI is convex, the BOW of one surface thereof is preferably +25 to +300, more preferably +25 to +200, even more preferably +25 to +100, and the other surface. The BOW is preferably -25 to -300, more preferably -25 to -200, still more preferably -25 to -100.

On the other hand, when SORI is concave-shaped, the BOW of one surface thereof is preferably -25 to -300, more preferably -50 to -200, still more preferably -50 to -100, and the other The BOW of is preferably +25 to +300, more preferably +50 to +200, still more preferably +50 to +100.

In this manner, in addition to the above-described predetermined SORI, by defining the height of the center of the substrate as in the BOW, the convexity and the concave can be more clearly defined as numerical values, and a semiconductor substrate having a desired shape can be obtained.

Here, the BOW in the present invention has the intersection of the reference plane S2 obtained from the front and rear middle plane e as shown in FIG. 3 and the substrate center line f orthogonal to this, and the front and rear middle plane e. In the distance (d), the absolute value (d) is denoted as positive if the front and middle surfaces (e) are higher than the reference surface (S2) and negative if the front and middle surfaces (e) are lower than the reference surface (S2). Is defined as BOW.

In addition, when the substrate surface sufficiently reflects light and an interference fringe with the device reference surface is obtained, the BOW can be measured using an optical interference flatness tester. Conversely, when the substrate surface is rough and no interference fringes are obtained, the BOW can be obtained by scanning the laser displacement meter as if sandwiched between the front and back of the substrate.

The thickness of the semiconductor substrate is not particularly limited, but is preferably 0.5 to 3.0 mm, more preferably 0.6 to 1.2 mm in view of the handling of the substrate and the thickness of the exposure apparatus.

In the present invention, the shape of the semiconductor substrate is not particularly limited, and a general shape such as a circular shape or a rectangular shape can be adopted in plan view. In addition, such diameter or diagonal length is not particularly limited, but is preferably 100 to 450 mm, more preferably 200 to 300 mm.

The material of the semiconductor substrate of the present invention is not particularly limited and may be a conventionally known material such as a glass material or a ceramic material. However, the substrate for the transmissive polysilicon TFT needs to pass light. Synthetic quartz glass substrates are preferred, and in the case of reflective TFTs, polysilicon substrates are preferred.

As a manufacturing method of the board | substrate for semiconductors of this invention which has SORI and BOW mentioned above, the method of making a desired shape in any process of a slice process, a lapping process, and a grinding | polishing process is considered.

However, in the slicing step, in the case of cutting by a general wire saw, since the ingot is cut while hanging the slurry including the abrasive material on a straight line of the wire, the obtained semiconductor substrate is placed on the wire in the horizontal direction, that is, in the wire direction. Therefore, it becomes straight. On the other hand, in the direction perpendicular to the wire direction on the surface of the semiconductor substrate, a method of lowering or raising the ingot is adopted. However, since this direction is a mechanism for linearly moving with good reproducibility, it moves in a curved manner and thus SORI and It is difficult to control the BOW arbitrarily.

In addition, since the thickness of the semiconductor substrate is relatively thin with respect to the diameter, there is little repetitive stress of the substrate which serves as a driving force for forming a desired SORI shape in the lapping process or the polishing process. Therefore, the SORI and the BOW are maintained even when the lapping is in progress. Therefore, the substrate shape can be freely changed, such as the surface SORI being convex, that is, BOW plus, and the back SORI being concave, that is, BOW minus. It's hard to control.

Then, in this invention, the semiconductor substrate which has desired SORI and BOW shape in a lapping process is manufactured using the transfer disk. The disk for transfer used in the present invention differs in shape depending on the type of the wrap apparatus used in the transfer step and the shape of the target substrate for semiconductor.

For example, in the case of using the double-sided wrap apparatus, the SORI-shaped semiconductor substrate having a center symmetry has a surface and a back surface, passes through the midpoint on the center line connecting the center points of the front and back surfaces, and is perpendicular to the center line. 2 raw material substrates are installed in the double-sided wrap apparatus, with the preparation process of preparing a transfer disk having SORI and thickness fluctuations in which the front and rear surfaces thereof are symmetrically interposed therebetween, and sandwiching the prepared transfer disk. The transfer process of processing the surface which does not contact the transfer disk in a raw material board | substrate, and producing the two transfer boards in which the shape of the transfer disk was transferred to single side | surface, and the both surfaces of the transfer substrate obtained by this transfer process are wrapped. Or a lapping step of producing a processed substrate by wrapping only a surface on which the shape of the transfer disk in the transfer substrate is not transferred, and both sides or one side of the wrapped substrate Can be manufactured by polishing

In the case of using a single-sided wrap device, the SORI-shaped semiconductor substrate having a center symmetry has a surface and a back surface, passes through an intermediate point on the center line connecting the center points of these front and rear surfaces, and is perpendicular to the surface perpendicular to the center line. A preparatory process for preparing a transfer disk in which one surface of the surface is parallel and the other surface in contact with the raw material substrate in the front and back surfaces is orthogonal to the center line and symmetrical with respect to the center line; The raw material substrate is installed in a single-side wrapping apparatus so as to be in contact with the other side of the substrate, and the surface not being in contact with the transfer disc in the raw material substrate is processed to produce a transfer substrate in which the shape of the transfer disc is transferred to one side. The transfer process and the both sides of the transfer substrate are wrapped, or only the surface on which the shape of the transfer disc in the transfer substrate is not transferred is wrapped to prepare a wrap substrate. Wrap process and can be produced by polishing the both sides or one side of the lap processing a substrate.

The double-sided wrap device and the single-sided wrap device used in the present invention are not particularly limited and can be appropriately selected from known devices.

The rotation speed of the double-sided wrap device and the single-sided wrap device in the transfer step is preferably 5 to 50 rpm, and the load is preferably 10 to 200 g / cm ² , and in the double-side wrap device, the value taken per unit time is almost the same on both sides. It is preferable.

The material of the transfer disk is not particularly limited, and alumina ceramics, metals, resins, and the like can be employed, but alumina ceramics are preferred from the viewpoint of deformation and breakage.

Moreover, as an abrasive | polishing agent, silicon carbide type | system | group, artificial diamond, etc. can be used besides using what disperse | distributed 20-60 mass% with water using the alumina type abrasive material whose average particle diameter becomes like this.

In the transfer step, when a double-sided wrap device is used, as described above, two raw material substrates are enclosed in a carrier so as to sandwich the transfer disc, and are respectively installed on the lower wrap plate and the upper wrap plate of the double-side wrap device. do.

Usually, the double-sided wrap apparatus adjusts the thickness of the carrier according to the thickness of the raw material substrate, but in the case of the present invention, it is preferable to set the thickness of the carrier in consideration of the thickness of the two raw material substrates and the transfer disk. desirable. In addition, it can process without changing with normal lap processing.

In this step, since the one side of each of the two raw material substrates is simultaneously processed, the shape of the transfer master is transferred only to the one side that contacts the lower lap plate and the upper lap plate, while the surface in contact with the transfer disc is It does not change because it is not processed.

Since the center of the transfer disk is thicker than the outer periphery, the processing pressure of the raw material substrate and the wrap plate is concentrated in the center of the raw material substrate at the beginning of the transfer process. At this time, since the raw material substrate is thin and the repulsive force is low, cutting proceeds selectively from the center of the raw material substrate. When cutting progresses and processing reaches to the outer periphery of a raw material board | substrate, the shape of the transfer disk is transferred to the surface on the opposite side of the raw material board | substrate which is not in contact with the transfer disk (namely, the surface which is in contact with the lap plate).

When the outer peripheral portion of the transfer disc is thinner than the central portion, the outer peripheral portion of the raw material substrate obtained in the transfer step becomes thicker than the central portion due to the difference in thickness between the outer peripheral portion and the central portion. On the contrary, when the outer peripheral portion of the transfer disc is thicker than the central portion, the outer peripheral portion of the raw material substrate obtained in the transfer step becomes thinner than the central portion due to the difference in thickness between the outer peripheral portion and the central portion. In this manner, the shape to be transferred can be generated according to the shape of the transfer disk.

On the other hand, in the case of using the single-sided wrap apparatus in the transfer step, a transfer disc is provided between the raw material substrate and the top plate of the single-side wrap apparatus so that the flat surface faces the top plate side. The raw material substrate is processed after fixing the carrier to the top plate so as not to fall off in the horizontal direction. The raw material substrate is processed by the lower lap platen of the single-sided wrap device, and as the process is advanced, the shape of the transfer disk is transferred only to the surface in contact with the lower lap platen side of the raw material substrate.

About the transfer board | substrate which passed the above transfer process, a lapping process is performed using a double-sided wrap apparatus or a single-sided wrap apparatus. As for the rotation speed of a double-sided wrap apparatus and a single-sided wrap apparatus, 5-50 rpm is preferable, and, as for a load, 10-200 g / cm <^2> is preferable.

In the case of using the double-sided wrap apparatus, the transfer substrate is provided so that the flat surface faces the upper wrap plate side of the double-sided wrap apparatus, and a carrier is installed to prevent the substrate from falling off, and the normal wrap processing is performed. As a result, a wrap substrate having a top surface convex and a bottom surface concave is obtained. Although the value of SORI of a lapping board | substrate becomes about half of the value of SORI before lapping, a reduction degree also depends on the diameter and thickness of a transfer board | substrate.

The principle that the shape of the front and back surfaces is made is that, due to the thickness variation already present in the initial shape, the in-plane processing pressure difference occurs on both sides from the initial stage of processing, whereby the part to be cut is selectively changed over time. . Therefore, the processing pressure distribution in the substrate surface also changes accordingly, and the processing proceeds. As a result, the substrate shape before the original wrapping process is halved while being reflected on the shape of both surfaces, depending on the repeating force of the transfer substrate, that is, the diameter and thickness of the transfer substrate.

In the case of using a single-sided wrap device, a transfer substrate is provided between the lower wrap plate and the top plate so as to face a flat surface on the lower wrap plate side, and the carrier is provided and wrapped so that the transfer substrate does not fall off in the horizontal direction. In this case, since only the surface which is not transferred is wrapped, SORI of the transfer side surface of the original transfer disk and SORI of the obtained wrapped substrate become equal.

The lapping board | substrate obtained by the said lapping process performs the grinding | polishing process which further polishes both surfaces or one side as needed for mirroring.

In the polishing step, a double-side polishing device or a single-side polishing device can be used. The surface to be mirrored may be either a surface having convex SORI and BOW plus or a surface having concave SORI and BOW minus.

In this way, various kinds of semiconductor substrates having desired shapes (SORI and BOW) as shown in FIG. 1 can be finally produced.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

5, the embodiment of the transfer process using the double-sided wrap apparatus 1 which concerns on 1st Embodiment of this invention is shown.

In this embodiment, as shown in FIG. 5, the double-sided wrap apparatus (in the state which was enclosed in the carrier 12 so that the transfer disk 10 may be inserted in the two raw material boards 11 and 11, respectively) It is provided in the lower lap plate 13 and the upper lap plate 14 of 1).

The transfer disc 10 used in this embodiment passes through the center point 100A of the surface 100 of the transfer disc 10 and the center point 110A of the back surface 110 as shown in FIG. 6. The surface 100 and the back surface 110 with respect to the imaginary surface S1 which passes through the midpoint M1 of each center point 100A, 110A in the center line L1, and is orthogonal to the center line L1. ) Has a convex SORI and thickness variation that face each other symmetrically, and have a front and back shape symmetrical with respect to the center line L1.

In addition, the raw material substrate 11 used by this embodiment slices a synthetic quartz glass ingot using a wire saw, performs a chamfering process, is produced by removing the saw mark of the front and back surface by a double-sided wrap apparatus, and is produced 100 mm, thickness 630 micrometers, SORI of the front and back surfaces are 6 micrometers, and BOW of the front and back surfaces are +3 micrometers, -3 micrometers, respectively, and a disc shape of 1 micrometer of thickness fluctuations.

In the state where the two raw material substrates 11 are provided as described above, the one side of each raw material substrate 11 is simultaneously processed at a rotational speed of 20 rpm and a load of 100 g / cm ² of the double-sided wrapping apparatus 1, and the one side The transfer board | substrate with which the shape of the transfer disk 10 was transferred to the side is obtained.

Subsequently, as shown in FIG. 7, one sheet of the transfer substrate 11A on which the shape of the transfer disk 10 is transferred on one side is flat, and the flat surface is the upper wrap plate 14 of the double-side wrap apparatus 1. It is installed inside the carrier 12 so as to face the side, and double-sided lapping is performed at a rotational speed of 20 rpm and a load of 100 g / cm ² to transfer the shape of the transfer disc 10 to the surface not transferred in the transfer step. The lapping board | substrate by which the upper side surface was convex and the lower side surface was concave-shaped is obtained.

By mirror-hardening both surfaces with a double-side polishing apparatus (not shown) with respect to the obtained lapping board | substrate, the synthetic quartz glass substrate which has SORI which is central symmetry as shown to FIG. 1 (A) is obtained. Specifically, the surface has a convex shape with a SORI of 50 µm, a BOW of +25 µm, a concave shape with a SORI of 50 µm on the back, a BOW of -25 µm, an in-plane thickness variation of 1 µm, and a thickness of 500. A synthetic quartz glass substrate having a mirror-surface on both sides having a thickness of µm is obtained.

8, the embodiment of the transfer process using the single-sided wrap apparatus 2 which concerns on 2nd Embodiment of this invention is shown. In addition, in 2nd Embodiment, the same code | symbol is attached | subjected about the same member as the said 1st Embodiment.

The transfer disc 20 used in this embodiment passes through the center point 200A of the surface 200 of the transfer disc 20 and the center point 210A of the back surface 210 as shown in FIG. 9. The surface 200 is parallel (flat) with respect to the imaginary surface S2 which passes through the midpoint M2 of each center point 200A, 210A in the center line L2, and is orthogonal to the center line L2. Face), the rear face 210 is perpendicular to the center line L2, and has a shape corresponding to the convex shape symmetrical with respect to the center line L2.

In addition, the raw material substrate 21 used by this embodiment is the original board which was produced by the method similar to 1st Embodiment, 200 mm in diameter, thickness of 855 micrometers, SORI of the front and back side, respectively, 6 micrometers, and thickness fluctuation of 1 micrometer. Is a synthetic quartz glass substrate.

As shown in Fig. 8, the flat surface of the transfer disk 20 is disposed to face the top plate 25 side, and the raw surface is brought into contact with the surface according to the convex shape in the transfer disk 20. The transfer disk 20 in the raw material substrate 21 at a rotational speed of 20 rpm and a load of 100 g / cm ² in a state in which the substrate 21 is installed in the single-side wrap apparatus 2 and these are enclosed in the carrier 12. By processing only the surface which is not in contact with the lower wrap plate 13, a transfer substrate is obtained in which the shape of the transfer master 20 is transferred to one side.

Subsequently, as shown in FIG. 10, between the lower wrap surface 13 and the top plate 25 of the one-side wrap apparatus 2, the transfer substrate 21A on which the shape of the transfer disc 20 is transferred on one side is transferred. ) Is installed inside the carrier 12 in a state where the shape of the transfer disk 20 is transferred to the top plate 25 side, and the single-side lapping is performed at a rotational speed of 20 rpm and a load of 100 g / cm ² . By carrying out the transfer of the shape of the transfer disk 20 also to the surface which is not transferred in the transfer step, a wrap processed substrate obtained by lapping the upper side into the concave shape and the lower side into the convex shape is obtained.

By mirror-hardening both surfaces about the obtained lapping board | substrate similarly to 1st Embodiment, the synthetic quartz glass substrate which has SORI which is central symmetry as shown to FIG. 1 (A) is obtained. Specifically, the convex shape and the BOW whose surface is SORI 100 micrometers are +50 micrometer, and the concave shape and BOW which are SORI 110 micrometers are -50 micrometer, and both surfaces whose thickness fluctuations are 1 micrometer and thickness 725 micrometer A mirror surface synthetic quartz glass substrate is obtained.

In addition, the shape, thickness and SORI of the transfer disk used in the manufacturing method of the semiconductor substrate of this invention, the shape and material of a raw material board, the specific conditions of each process, etc. are not limited to said each embodiment, Modifications and improvements within the scope in which the objects and effects of the present invention can be achieved are included in the present invention.

For example, in the case of manufacturing a semiconductor substrate having SORI that is not centrally symmetrical by using a double-sided wrap apparatus, in the first embodiment, a transfer disk 30 as shown in FIG. 11 may be used.

The transfer disk 30 has an intermediate point between the vertices 300A and 310A in a straight line L3 passing through the vertex 300A on the front surface 300 and the vertex 310A on the back surface 310. With respect to the virtual surface S3 which passes through M3 and is orthogonal to the straight line L3, the surface 300 and the back surface 310 have convex SORI which symmetrically face each other.

By using the transfer disk 30, transfer processing, lapping, polishing, etc. are performed in the same manner as in the first embodiment, whereby the convex vertices as shown in FIG. A semiconductor substrate having a convex shape shifted in the direction and having a positive BOW can be obtained.

In addition, when manufacturing a semiconductor substrate which has SORI which is not central symmetry using a single-sided wrap apparatus, in the said 2nd Embodiment, the transfer disk 40 as shown in FIG. 12 may be used.

The transfer disk 40 has the vertex 410A and its portion in a straight line L4 passing through the vertex 410A of the back surface 410 and the partial point 400A on the surface 400 facing it. SORI whose surface 400 is parallel (flat surface) and the back surface 410 is convex with respect to the imaginary surface S4 which passes through the midpoint M4 of the point 400, and is orthogonal to the straight line L4. Have

By using the transfer disk 40, transfer processing, lapping, polishing, and the like are performed in the same manner as in the second embodiment, the convex vertices as shown in FIG. A semiconductor substrate having a convex shape shifted in the direction and having a positive BOW can be obtained.

In addition, in the said 1st Embodiment, when providing the XY axis which goes straight on the surface of the transfer disk as shown in FIG. 13, the thickness shape seen from the cross section of the X direction and the Y direction is X direction and Y direction. In the case of using a transfer disc having a thickness variation linearly symmetric with respect to a line (Y axis in Fig. 13) passing through the center on the surface of the transfer disc having a different inclination from the center to the outer circumference, The semiconductor substrate as shown is obtained. In addition, the curve inside the board | substrate in FIG. 13 has shown the contour line of thickness.

EXAMPLE

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example.

Example 1

As a master disc for transfer, the thing as shown in FIG. 6 was prepared. Specifically, the SORI of the front and back surfaces are all convex, 110 µm having the same convex shape, passing through the midpoint on the center line connecting the center points of the front and back surfaces, and the front and back surfaces are symmetrically opposed to the surface perpendicular to the center line. A transfer disk made of alumina ceramic having a thickness of 3 mm and a diameter of 100 mm at the center having a thickness variation of 220 µm was prepared.

In addition, a synthetic quartz glass ingot was sliced using a wire saw E450E-12 manufactured by Toyo ATEC Co., Ltd., chamfered, and the saw marks on the front and back were removed by a double-sided wrap apparatus, and a diameter of 100 mm and a thickness of 630 µm, The raw material board | substrate whose SORI of front and back surface is 6 micrometers, and thickness fluctuations is 1 micrometer, respectively was prepared.

Two raw material substrates were installed on the lower lap plate and the upper lap plate of the double-sided wrap device, respectively, by inserting the transfer disk, and using a wrap material composed of alumina with the number # 1000 as the main component. One side of each raw material substrate was simultaneously processed at 100 g / cm ² , and two transfer substrates on which the shape of the transfer disk was transferred to one side were obtained. As for the shape of the obtained transfer substrate, all the single side | surfaces were concave 110 micrometers in concave shape.

One sheet of the obtained transfer substrate was installed in a double-sided wrap apparatus, and double-sided lapping was performed at a rotational speed of 20 rpm and a load of 100 g / cm ² using the same wrapping material as the transfer step, and the transfer surface was also transferred to the surface not transferred in the previous transfer step. The shape of the used disk was transferred. And the surface-convex convex shape and BOW of +25 micrometer were obtained, and the back surface obtained the concave shape of SORI 50 micrometer, and the wrapping board of which BOW is -25 micrometer.

Moreover, as a process of grind | polishing both surfaces of the obtained lapping board | substrate, it mirror-mirrors both surfaces with a double-sided apparatus, and the surface has a convex shape of BORI 50 micrometers and a BOW of +25 micrometers, and the back surface of the concave shape and BOW of SORI 50 micrometers is Synthetic quartz glass substrates having a mirror surface of +25 μm, in-plane thickness variation (TTV) of 1 μm, and a thickness of 500 μm were mirror surfaces.

Subsequently, after supplying silane gas to the surface of the obtained synthetic quartz glass substrate, forming an amorphous silicon film, and performing annealing and forming a polysilicon film, the film-formed surface was convex shape of SORI 122 micrometers, The surface was changed into a concave shape of SORI 122 µm.

Subsequently, heat treatment at 1050 ° C. was further performed for 1 hour, whereby the formed film was changed into a convex shape of SORI 4 μm, the other surface was changed into a concave shape of SORI 4 μm, and the in-plane thickness variation (TTV) was 1. Synthetic quartz glass substrates for polysilicon TFTs having a micrometer and almost flat SORI were obtained.

Example 2

After performing the transfer process by the method similar to Example 1 using a double-sided wrap apparatus, the obtained transfer board | substrate is installed so that the surface to which the shape of the transfer disk was transferred may face the top plate side of a single-sided wrap apparatus, and it rotates Single-sided lapping was performed at several 20 rpm and a load of 100 g / cm ² to obtain a lapping substrate.

In addition, both surfaces of the obtained wrapped substrate were polished by the same method as in Example 1, and the surface was convex and BOW having a SORI 110 µm of +55 µm, and the concave shape and BOW of SORI 110 µm had a surface of -55 µm. A synthetic quartz glass substrate having a mirror surface of both surfaces having an in-plane thickness variation (TTV) of 1 µm and a thickness of 500 µm was obtained.

Next, when a polysilicon film was formed on the obtained synthetic quartz glass substrate by the method similar to Example 1, the film-formed surface was changed into the convex shape of SORI 122 micrometers, and the other surface was changed into the concave shape of SORI 122 micrometers.

Subsequently, heat treatment at 1050 ° C. was further performed for 1 hour, whereby the formed film was changed into a convex shape of SORI 4 μm, the other surface was changed into a concave shape of SORI 4 μm, and the in-plane thickness variation (TTV) was 1. Synthetic quartz glass substrates for polysilicon TFTs having a micrometer and almost flat SORI were obtained.

Example 3

As a master disc for transfer, the thing as shown in FIG. 9 was prepared. Specifically, one of the front and back surfaces is flat, and the other surface is orthogonal to the center line connecting the centers of the front and back surfaces, and convexly convex with the center line. A transfer disk made of alumina ceramic having a center thickness of 2 mm and a diameter of 200 mm having an in-plane thickness variation (TTV) of 110 µm was prepared.

As a raw material board | substrate, the synthetic quartz glass board | substrate of diameter 200mm, thickness 855 micrometers, SORI of the front and back side, 6 micrometers, and thickness variation of 1 micrometer each was prepared.

Between this raw material board | substrate and the top plate of a single-sided wrap apparatus, the said transfer disk was provided so that a flat surface may face the top plate side, and the rotation speed is 20 rpm and the load using the wrap material which consists of alumina of the number # 1000 as a main component. The one side of the raw material substrate was processed at 100 g / cm ^2, and a transfer substrate on which the shape of the transfer disc was transferred to the one side was obtained. As for the shape of the obtained transfer board | substrate, one side was flat and the other surface was bent by 110 micrometers in concave shape.

Subsequently, a transfer substrate is provided between the lower lap surface plate and the top plate of the single-sided wrap apparatus so that the transferred surface faces the top plate side of the single-sided wrap apparatus, and the rotation speed is 20 rpm and the load is 100 g using the same wrapping material as the transfer process. Single side lapping was performed at / cm ² to obtain a lapping substrate. The obtained lapping board | substrate obtained the lapping board | substrate whose surface is convex shape of SORI 110 micrometers, and the back surface is concave shape of SORI 110 micrometers.

In addition, the surface of the convex side was mirror-mirrored with a one-side polishing apparatus, and the surface was convex with a SORI 110 µm and the BOW was +55 µm, the concave shape with a SORI 110 µm and the BOW was -55 µm, and the in-plane thickness fluctuations. (TTV) was 1 micrometer and the synthetic quartz glass substrate which is 725 micrometers in thickness was obtained.

When the polysilicon film was formed on the obtained synthetic quartz glass substrate by the method similar to Example 1, the film-formed surface was changed into the convex shape of SORI 122 micrometers, and the other surface was changed to the concave shape of SORI 122 micrometers.

Subsequently, heat treatment at 1050 ° C. for one hour further changed the convex shape of the film formed into a convex shape of SORI of 4 μm, the other surface into a concave shape of SORI of 4 μm, and in-plane thickness variation (TTV) of one. Synthetic quartz glass substrates for polysilicon TFTs having a micrometer and almost flat SORI were obtained.

Example 4

The transfer substrate obtained by performing the transfer process in the same manner as in Example 3 was subjected to lapping on both sides by the same method as in Example 1, and the surface was convex with a SORI of 50 μm, and the back surface was with a concave shape with a SORI of 50 μm. A lab processed substrate was obtained.

In addition, both surfaces were polished by the same method as Example 1, and the surface was convex and BOW of +25 micrometer in SORI 50 micrometers, the concave shape and BOW of -25 micrometer in SORI 50 micrometer, and thickness fluctuations were A synthetic quartz glass substrate having a mirror surface of 1 μm and a thickness of 725 μm was obtained.

When the polysilicon film was formed on the obtained synthetic quartz glass substrate by the method similar to Example 1, the film-formed surface was changed into the convex shape of SORI 122 micrometers, and the other surface was changed to the concave shape of SORI 122 micrometers.

Subsequently, heat treatment at 1050 ° C. was further performed for 1 hour, whereby the formed film was changed into a convex shape of SORI 4 μm, the other surface was changed into a concave shape of SORI 4 μm, and the in-plane thickness variation (TTV) was 1. Synthetic quartz glass substrates for polysilicon TFTs having a micrometer and almost flat SORI were obtained.

Example 5

As a master disc for transfer, a shape as shown in Fig. 11 was prepared. Specifically, the shapes of the front and back surfaces are convex shapes that are symmetrical to each other, their SORI is 110 µm, the in-plane thickness variation (TTV) is 220 µm, and the place where the surface is 30 mm apart from the center point of the front and rear surfaces is the thickest. A transfer disk made of alumina ceramic having a thickness of 3000 µm and a diameter of 100 mm was prepared.

As a raw material board | substrate, the synthetic quartz glass board | substrate of diameter 100mm, thickness 630 micrometers, SORI of the front and back surfaces of 6 micrometers, and in-plane thickness variation (TTV) of 1 micrometer was respectively prepared.

By the method similar to Example 1, the single side | surface side of two raw material substrates was processed simultaneously by the double-sided wrap apparatus, and the transfer board | substrate with which the shape of the transfer disk was transferred to the one side side was obtained. As for the shape of the obtained transfer substrate, all the single side | surfaces were concave 110 micrometers in concave shape. In addition, the thinnest part of the concave shape was shifted by 30 mm from the center.

The obtained transfer substrate was installed in the double-sided wrap apparatus, double-sided lapping was performed in the same manner as in Example 1, and the shape of the transfer disc was transferred also to the surface not transferred in the previous transfer step, and the surface was SORI 50 µm. The convex shape and the back surface of the concave-shaped board | substrate with a concave shape of 50 micrometers were obtained.

In addition, the convex side of the obtained wrap substrate was mirrored with a single-side polishing apparatus, and the convex shape and the BOW were +20 μm with a mirror surface having a SORI of 50 μm, and the concave shape and BOW having a roughness of SORI 50 μm with a surface of -20. A synthetic quartz glass substrate having a thickness of 1 µm, an in-plane thickness variation (TTV) of 1 µm, and a thickness of 500 µm was obtained.

Subsequently, when the polysilicon film was formed on the surface of the obtained synthetic quartz glass substrate by the method similar to Example 1, the film-formed surface changed into the convex shape of SORI 122 micrometers, and the other surface changed into the concave shape of SORI 122 micrometers. It became.

Subsequently, heat treatment at 1100 ° C. for 2 hours was further performed, whereby the surface formed into a convex shape of SORI 4 μm, the other surface was changed into a concave shape of SORI 4 μm, and the thickness variation was 1 μm. A synthetic quartz glass substrate for polysilicon TFTs having a flat SORI was obtained.

Example 6

In the same manner as in Example 5, one of the front and back surfaces was flat, and the other surface was convex, 110 µm squared, and the in-plane thickness variation (TTV) was 220 µm, which was shifted 30 mm from the center point of the front and rear surfaces. The thickest place, the thickness of the part was 3000 micrometers, and the transfer disk made from an alumina ceramic of diameter 100mm was prepared.

As a raw material board | substrate, the thing similar to Example 5 was prepared.

By the method similar to Example 3, the single side | surface side of the raw material board | substrate was processed with the single side | surface wrap apparatus, and the transfer board | substrate with which the shape of the transfer disk was transferred to the one side side was obtained. As for the shape of the obtained transfer board | substrate, one side was flat and the other surface was bent by 110 micrometers in concave shape. In addition, the thinnest part of the concave shape was shifted by 30 mm from the center.

The obtained transfer substrate was placed in a single-sided wrap apparatus and subjected to single-sided lapping in the same manner as in Example 2, to transfer the shape of the transfer disc to the surface on the opposite side of the transfer substrate which was not transferred in the transfer step, so that the surface The lapping board | substrate which is convex shape of SORI 110 micrometers, and whose back surface is concave shape of SORI 110 micrometers was obtained.

The convex side of the obtained wrap substrate was mirrored with a single-side polishing apparatus, and the mirror surface had a convex shape of SORI 110 µm and a BOW of +50 µm, and the rough surface had a concave shape of SORI 110 µm and a BOW of -50 µm. And the in-plane thickness variation (TTV) were 1 micrometer, and the synthetic quartz glass substrate which is 500 micrometers in thickness was obtained.

Subsequently, when the polysilicon film was formed on the surface of the obtained synthetic quartz glass substrate by the method similar to Example 1, the film-formed surface changed into the convex shape of SORI 122 micrometers, and the other surface changed into the concave shape of SORI 122 micrometers. It became.

Subsequently, heat treatment at 1100 ° C. for 2 hours was further performed to form a convex shape of SORI 4 μm, the other side being a concave shape of SORI 4 μm, and an in-plane thickness variation of 1 μm. Synthetic quartz glass substrates for polysilicon TFTs with an almost flat SORI were obtained.

Comparative Example 1

A transfer disk made of alumina ceramic having a diameter of 100 mm, having a SORI of front and back surface of 110 µm, a convex shape of one side, a concave shape on the other side, and a thickness of 2 mm and a constant thickness variation of 2 µm. Was prepared and the same thing as Example 1 was prepared as a raw material substrate.

The raw material substrate was transferred by the method similar to Example 1 using the double-sided wrap apparatus, and the transfer substrate whose SORI of the front and back surface is 1 micrometer was obtained.

In addition, the obtained transfer substrate was double-sided mirrored with a double-side polishing apparatus, the SORI of the front and back surfaces was 1 µm, the BOW of the surface was +0.5 µm, the BOW of the back surface was -0.5 µm, and the in-plane thickness variation (TTV) was 1 µm. The synthetic quartz glass substrate whose mirror-surface was 500 micrometers in thickness was obtained.

When the polysilicon film was formed in the obtained synthetic quartz glass substrate similarly to Example 1, the film-formed surface was changed into the convex shape of SORI 120 micrometers, and the other surface was changed to the concave shape of SORI 120 micrometers.

Subsequently, the heat treatment at 1050 ° C. was performed for an additional 1 hour, whereby the in-plane thickness variation (TTV) was 1 μm, and the film formed surface was convex with SORI 60 μm, and the other surface was concave with SORI 61 μm. Changed, and the desired flat SORI was not obtained.

Comparative Example 2

As a transfer disk, SORI of the front and back surface is 110 µm, one side is convex, the other surface is concave, the in-plane thickness variation (TTV) is 1 µm, the thickness is 2 mm, and the diameter is 200 mm. The transfer disk was prepared and the same thing as Example 4 was prepared as a raw material substrate.

After carrying out the transfer process to the raw material substrate using the single-sided wrap apparatus in the same manner as in Example 4, the obtained transfer substrate was subjected to lapping at a rotational speed of 20 rpm and a load of 100 g / cm ² with a double-sided wrap apparatus, so that the SORI of the front and back surfaces was A wrap substrate having a thickness of 1 μm was obtained.

In addition, the obtained lapping substrate was polished on both sides, and the SORI of the front and back surfaces was 1 µm, the BOW of the surface was +0.5 µm, the BOW of the rear surface was -0.5 µm, and the in-plane thickness variation (TTV) was 1 µm. The synthetic quartz glass substrate which is 725 micrometers was obtained.

A polysilicon film was formed on the obtained synthetic quartz glass substrate in the same manner as in Example 1, and when the in-plane thickness variation (TTV) was 1 µm, the formed film was convex with SORI 120 µm and the other surface was SORI 120. It changed into the concave shape of 탆.

Subsequently, heat treatment at 1050 ° C. was further performed for 1 hour, whereby the surface formed with concave shape with SORI 60 μm and the other side with concave shape with SORI 60 μm while the in-plane thickness variation (TTV) was 1 μm. The desired flat SORI was not obtained.

Comparative Example 3

SORI of the front and back surface is 110 µm, the one side is convex, the other surface is concave, the in-plane thickness variation (TTV) is 1 µm, the thickness is 2 mm, and the diameter is 110 mm. The transfer disk was prepared and the same thing as Example 2 was prepared as a raw material substrate.

After the transfer process was carried out to the raw material substrate using the double-sided wrap apparatus in the same manner as in Example 2, the transfer substrate was placed so that the flat surface on which the shape of the transfer disc was not transferred was directed toward the top plate side of the single-sided wrap apparatus. And the lapping process on the conditions similar to Example 2, and the lapping board | substrate whose surface SORI is 1 micrometer was obtained.

In addition, the single-sided surface of the wrap substrate obtained by the single-side polishing apparatus was mirror-finished, the surface SORI was 1 µm, the BOW of the surface was +0.5 µm, the BOW of the rear surface was -0.5 µm, and the in-plane thickness variation (TTV) was 1 µm. And a synthetic quartz glass substrate having a thickness of 500 µm.

When the polysilicon film was formed on the obtained synthetic quartz glass substrate by the method similar to Example 1, the film-formed surface was changed into the convex shape of SORI 120 micrometers, and the other surface was changed to the concave shape of SORI 120 micrometers.

Subsequently, heat treatment at 1050 ° C. was further performed for 1 hour, whereby the surface formed with concave shape with SORI 60 μm and the other side with concave shape with SORI 60 μm while the in-plane thickness variation (TTV) was 1 μm. The desired flat SORI was not obtained.

[Comparative Example 4]

As a transfer disk, SORI of the front and back surface is 110 µm, one side is convex, the other surface is concave, the in-plane thickness variation (TTV) is 1 µm, the thickness is 2 mm, and the diameter is 200 mm. The used disk was prepared, and the same thing as Example 4 was prepared as a raw material substrate.

After carrying out the transfer process of the raw material substrate using the single-sided wrap apparatus in the same manner as in Example 4, the transfer substrate was placed so that the flat surface on which the shape of the transfer disc was not transferred is directed toward the top plate side of the single-sided wrap apparatus. And the lapping process on the conditions similar to Example 2, and the lapping board | substrate whose surface SORI is 1 micrometer was obtained.

In addition, the single-sided surface of the wrap substrate obtained by the single-side polishing apparatus was mirror-finished, the surface SORI was 1 µm, the BOW of the surface was +0.5 µm, the BOW of the rear surface was -0.5 µm, and the in-plane thickness variation (TTV) was 1 µm. And a synthetic quartz glass substrate having a thickness of 725 µm.

When the polysilicon film was formed in the obtained synthetic quartz glass substrate similarly to Example 1, the film-formed surface was changed into the convex shape of SORI 120 micrometers, and the other surface was changed to the concave shape of SORI 120 micrometers.

Subsequently, heat treatment at 1050 ° C. was further performed for 1 hour, whereby the surface formed into a convex shape of SORI 60 μm and the other surface changed into a concave shape of SORI 61 μm while the thickness variation was 1 μm. The desired flat SORI was not obtained.

Table 1 shows the summary of each of the above Examples and Comparative Examples.

A: Substrate for Semiconductor
1: double side wrap device
2: one side wrap device
10, 20, 30, 40: transfer disc
11 A and 21 A: transfer substrate
100, 200, 300, 400: surface of transfer disk
110, 210, 310, 410: Back side of transfer disk
100 A, 110 A, 200 A, 210 A: Center point
L1, L2: Centerline
S1, S2, S3, S4: Virtual plane (face orthogonal to the centerline)
11, 21: raw material substrate

Claims (10)

A semiconductor substrate comprising one surface having a convex SORI and the other surface having a concave SORI having the same degree as the SORI, and having a thickness variation of 3 µm or less. The semiconductor substrate according to claim 1, wherein the SORI of each surface is 50 to 600 μm. The semiconductor substrate according to claim 1 or 2, wherein the BOW of one surface having the convex SORI is +25 to +300. The semiconductor substrate according to claim 1 or 2, wherein the BOW of the other surface having the concave SORI is from -25 to -300. The semiconductor substrate according to claim 1 or 2, wherein the thickness is 0.5 to 3 mm. The semiconductor substrate according to claim 1 or 2, wherein the semiconductor substrate has a circular shape having a diameter of 100 to 450 mm or a rectangular shape having a diagonal length of 100 to 450 mm in plan view. The substrate for semiconductors according to claim 1 or 2, which is made of synthetic quartz glass. The semiconductor substrate of Claim 1 or 2 which is a board | substrate for polysilicon TFTs. A transfer disk having a surface and a back surface, passing through an intermediate point on the center line connecting the center points of the front and back surfaces, and having a thickness variation and a thickness variation in which the surface and the back surface face symmetrically with respect to the surface orthogonal to the center line. With preparation process to do,
Two raw material substrates are provided in a double-sided wrap apparatus so as to sandwich the transfer disc, and the surface of each transfer substrate that does not come into contact with the transfer disc is processed so that the shape of the transfer disc is one-sided, respectively. A transfer step of producing two transfer substrates transferred to the substrate;
A lapping step of producing a wrapped substrate by lapping both surfaces of the transfer substrate or by wrapping only a surface on which the shape of the transfer disc is not transferred in the transfer step of the transfer substrate;
A method for manufacturing a semiconductor substrate, comprising polishing both sides or one side of the wrap substrate. One of the front and back surfaces is parallel to the surface perpendicular to the center line having a front surface and a rear surface, passing through the midpoint on the center line connecting the center points of the front and back surfaces, and the raw material substrate of the front and back surfaces. A preparatory step of preparing a transfer disk, wherein the other surface in contact with the center line is orthogonal to the center line and is symmetric with respect to the center line;
The raw material substrate is provided in a single-sided wrap apparatus so as to be in contact with the other surface of the transfer disc, and the surface not in contact with the transfer disc in the raw material substrate is processed so that the shape of the transfer disc is single-sided. A transfer step of producing a transfer substrate transferred to the
A lapping step of producing a wrapped substrate by lapping both surfaces of the transfer substrate or by wrapping only a surface on which the shape of the transfer disc is not transferred in the transfer step of the transfer substrate;
A method for manufacturing a semiconductor substrate, comprising polishing both sides or one side of the wrap substrate.

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