JP5629594B2 - Silicon thin film transfer wafer manufacturing method and polishing apparatus - Google Patents

Description

  The present invention relates to an SOI (Silicon on Insulator) wafer manufacturing method and manufacturing apparatus. More specifically, the present invention relates to an SOI wafer manufacturing method and a manufacturing apparatus that are characteristic of a wafer surface polishing method.

  SOI (Silicon on Insulator) wafers have been widely used in order to reduce parasitic capacitance and measure device speedup and power saving. In recent years, in order to build a fully depleted layer type SOI device, there is an increasing demand for a thin film SOI having an SOI layer (silicon layer) of 100 nm or less. This is because the device can be expected to increase in speed by reducing the thickness of the SOI layer. In addition to SOI, SOQ (Silicon on Quartz) in which the handle substrate (supporting substrate) is made of quartz and SOS (Silicon on Sapphire) made of sapphire have been attracting attention in recent years.

  As the SOI layer becomes thinner, the required in-plane film thickness uniformity is becoming stricter. In general, a thin-film SOI wafer is pre-implanted with hydrogen ions into a donor wafer and then bonded to a handle wafer, and the thin film is transferred from the donor side to the handle side along the hydrogen ion implantation interface (for example, a patent) Reference 1 and Non-Patent Document 1) and SiGen methods (for example, Patent Documents 2 to 4) can be cited. At this time, an ion implantation defect layer of about 0.1 μm remains in the transferred single crystal silicon thin film. The surface roughness is about 5 to 10 nm. This surface needs to be polished by chemical mechanical polishing (CMP) to have a mirror surface (RMS <0.3 nm). At this time, if the wafer surface is not uniformly polished, the remaining silicon film has a large surface. Variations in film thickness will be introduced.

  There are two ways of polishing (see FIG. 5). One is back surface reference polishing, which is a method in which the wafer 101 is fixed to a hard and flat polishing head 102 and polished (FIG. 5A). In this case, the front surface is polished according to the shape of the back surface, that is, the shape of the polishing head. On the other hand, the other is surface reference polishing, which does not fix the back surface of the wafer 101 to a hard and flat polishing head, but polishes it according to the surface shape by making it soft (see FIG. 5 (b)).

Japanese Patent No. 3048201 US Pat. No. 6,263,941 US Pat. No. 6,513,564 US Pat. No. 6,582,999

Bruel et al. Jpn. J. et al. Appl. Phys. 36 (1997) p. 1636 “Latest CMP Technology and Peripheral Components”, Technical Information Association, 2008, Chapter 6, Section 1, pages 255-258

However, each method has advantages and disadvantages. In the case of backside reference polishing, polishing is performed with the backside fixed to the polishing head, so the polishing amount greatly depends on the unevenness of the polishing head, uneven wafer thickness, foreign matter sandwiched between the polishing head and the wafer, etc. The Therefore, uniform polishing may be difficult.
Further, in the case of surface reference polishing, the mechanism of the polishing head becomes complicated (Non-Patent Document 2). In this case, since the back side of the wafer is supported by a soft protective film and pressure is applied from the back side, it is difficult to achieve a uniform pressure distribution due to changes in the protective film over time (deterioration). Is difficult.
The present invention is intended to solve the problems caused by the polishing treatment of such a single crystal silicon thin film, and by stabilizing the polishing treatment, in-plane film thickness variation of the single crystal silicon thin film is suppressed, The purpose is to make device characteristics constant.

In order to solve the above problem, the present inventor has reviewed each polishing method of back surface reference polishing and surface reference polishing.
As a result, when polishing a silicon thin film transfer wafer, if there is a defect in the pressure applied from the back side of the wafer, the in-plane film thickness of the single crystal silicon thin film will vary, resulting in unstable device characteristics. It was found that this led to
Based on this knowledge, the inventor paid attention to the pressurized state from the back surface of the wafer and intensively studied a method for controlling it. As a result, it was found that the material and form of the backing pad that abuts the back surface of the silicon thin film transfer wafer greatly affects the pressed state. Therefore, when various studies were made on the material and form of the backing pad, when a material having a predetermined bending rigidity was used as the backing pad, the pressure applied by the pressurization was appropriately averaged within the wafer surface, and the surface reference It was found that the uneven pressure distribution, which is a problem in polishing, is eliminated and uniformed. If such a material is in the form of a thin film material that can generate a displacement on the order of μm in response to pressure, a very small amount of material displacement becomes a cushion for cushioning, which causes a problem in backside reference polishing. It has been found that problems such as the dependency of the shape of the polishing head and fluctuations in film thickness due to foreign matter sandwiched between the silicon thin film transfer wafer and the polishing head can be avoided. As a result, if polishing is performed using such a backing pad, the in-plane film thickness variation of the single crystal silicon thin film can be controlled, leading to stabilization of device characteristics. The present inventor has come up with the present invention by obtaining the above various ideas and results.

That is, the present invention includes a hydrogen ion implantation step in which hydrogen ions are implanted from the surface of a single crystal silicon wafer and a hydrogen ion implantation layer is provided in the single crystal silicon wafer, the surface of the single crystal silicon wafer, and a handle wafer. A bonding step of bonding a surface of the bonding wafer to obtain a bonded wafer, a peeling step of peeling off the hydrogen ion implanted layer from the bonded wafer to obtain a wafer having a single crystal silicon thin film transferred thereto, and a single step exposed by peeling. And a polishing step for polishing the surface of the crystalline silicon thin film, wherein the polishing step comprises polishing cloth or polishing the single crystal silicon thin film on the surface of the silicon thin film transfer wafer. The back surface of the silicon thin film transfer wafer is brought into contact with a pad, and the bending rigidity is 150 G in Young's modulus. a is brought into contact with a backing pad made of a thin film material of a or more, the silicon thin film transfer wafer is pressed from the back surface through the backing pad, and the surface of the single crystal silicon thin film is polished by the polishing cloth or the polishing pad. This is a method for manufacturing a silicon thin film transfer wafer.
The present invention also provides a surface plate having a polishing cloth or polishing pad for polishing a single crystal silicon thin film on the surface of a silicon thin film transfer wafer, and a backing capable of contacting the back surface of the silicon thin film transfer wafer. A pad, a polishing head for holding the silicon thin film transfer wafer via the backing pad and bringing the silicon thin film transfer wafer into contact with the polishing cloth, and the silicon thin film transfer wafer via the backing pad and the polishing head Pressing means for pressing from the back surface and pressing the surface plate, and a driving mechanism for rotating the surface plate and / or driving the polishing head to polish the silicon thin film transfer wafer with the polishing cloth. A polishing apparatus for a silicon thin film transfer wafer having at least a bending rigidity of the backing pad A polishing apparatus of a silicon thin film transfer wafers characterized by comprising in Young's modulus from the above thin film material 150 GPa.

  According to the silicon thin film transfer wafer manufacturing method and polishing apparatus of the present invention, the in-plane film thickness variation of the single crystal silicon thin film can be suppressed, and as a result, the device characteristics can be made constant.

Schematic of polishing method according to the present invention Comparison of in-plane film thickness variation when using various backing pad materials Comparison of in-plane film thickness variation due to thickness of stainless steel backing pad Schematic diagram of SOI substrate manufacturing method Schematic diagram of backside reference polishing and frontside reference polishing

Hereinafter, the manufacturing method of the silicon thin film transfer wafer concerning this invention is demonstrated.
In the present invention, the SOI substrate can be manufactured by bonding a single crystal silicon substrate which is a donor substrate providing a silicon thin film and an insulating substrate which is a handle substrate.
The handle wafer is not particularly limited, but can be selected from the group consisting of a silicon wafer, a sapphire wafer, a quartz wafer, a silicon carbide wafer, and a glass wafer (for example, a borosilicate glass wafer, a crystallization gas wafer, etc.). This is because these handle wafers are used for general purposes, and the present invention is a method capable of producing a silicon thin film transfer wafer regardless of the type of these wafers.

  The method for producing a silicon thin film transfer wafer according to the present invention preferably uses a SOITEC method or a SiGen method (including these improved methods), and preferably implants hydrogen ions into the surface of the single crystal silicon wafer to produce the single crystal silicon. A hydrogen ion implantation step of providing a hydrogen ion implantation layer in the wafer; a bonding step of bonding the surface of the single crystal silicon wafer and a surface of the handle wafer to obtain a bonded wafer; and the hydrogen ion implantation from the bonded wafer It includes at least a peeling step for peeling the layers to obtain a wafer to which the single crystal silicon thin film has been transferred, and a mirroring step for mirroring the surface of the single crystal silicon thin film exposed by peeling. Through these steps, a silicon thin film transfer wafer in which the silicon thin film surface is mirror-finished can be obtained.

  The preferred thickness of the wafer is not particularly limited, but is preferably close to the thickness of the silicon wafer defined by SEMI or the like. This is because semiconductor devices are often set to handle wafers of this thickness. From this viewpoint, the thickness is preferably 300 to 900 μm.

Although it does not specifically limit as a single crystal silicon substrate, For example, it obtained by slicing the single crystal grown by the Czochralski method, for example, a diameter is 100-300 mm, a conductivity type is P type or N type, resistance A thing with a rate of about 10 ohm * cm is mentioned.
A thin insulating film is preferably formed in advance on the surface of the single crystal silicon substrate. This is because hydrogen ion implantation through the insulating film has an effect of suppressing channeling of implanted ions. As the insulating film, a silicon oxide film having a thickness of preferably 50 to 500 nm is preferable. This is because it is difficult to control the oxide film thickness if it is too thin, and it takes too much time if it is too thick. The silicon oxide film can be formed by a general thermal oxidation method.

Hereinafter, a method for manufacturing an SOI substrate will be described based on an example shown in FIG.
In the single crystal silicon substrate 12, hydrogen ions are implanted from the surface 12s, and an ion implantation layer 13 is formed in the silicon substrate. At this time, for example, the temperature of the single crystal silicon substrate is set to 250 to 450 ° C., and at a predetermined dose of hydrogen ions or rare gas ions at an implantation energy that can form an ion implantation layer from the surface to a desired depth. Inject one. As conditions at this time, for example, the implantation energy can be 50 to 100 keV, and the implantation dose can be 2 × 10 ¹⁶ to 1 × 10 ¹⁷ / cm ² .
As hydrogen ions to be implanted, hydrogen ions (H ⁺ ) having a dose of 2 × 10 ¹⁶ to 1 × 10 ¹⁷ (atoms / cm ² ), or 1 × 10 ^{16 to} 5 × 10 ¹⁶ (atoms / cm ² ). A hydrogen molecular ion (H ₂ ⁺ ) with a dose amount of is preferable.
The depth from the ion implantation surface 12s of the single crystal silicon substrate to the ion implantation layer 13 depends on the desired thickness of the silicon thin film provided on the insulating substrate 11, but is preferably about 200 to 400 nm, more preferably about 300 nm. It is. The thickness of the ion implantation layer 13 is such that it can be easily peeled off by mechanical impact, and is preferably about 200 to 400 nm, more preferably about 300 nm. The thickness of the single crystal silicon substrate is not particularly limited as long as it can contain such an ion-implanted layer. However, since it becomes uneconomical when it is too thick, it is usually 500 to 800 μm.

  Surface activation treatment may be performed on both or one of the hydrogen ion implantation surface 12 s of the single crystal silicon substrate on which the hydrogen ion implantation layer 13 has been previously implanted and the hydrogen ion implantation layer 13 and the surface 11 s of the insulating substrate 11. The surface activation treatment is a treatment for increasing the surface OH groups for activation, and examples thereof include plasma treatment, ozone treatment, or a combination thereof.

  Next, the hydrogen ion implantation surface 12s and the surface 11s of the insulating substrate are bonded to obtain the bonded substrate 14. For example, by bonding, a certain degree of bond strength can be secured at this point. In the case where at least one of the ion implantation surface 12s of the single crystal silicon substrate 12 and the surface 11s of the insulating substrate 11 is activated, these are generally used, for example, under reduced pressure or normal pressure, preferably without cooling or heating. It is possible to bond strongly at a strength that can withstand mechanical peeling in the subsequent process by simply adhering at a temperature of about room temperature (about 20 ° C.). The bonding strength may be increased by heating.

  For example, a mechanical impact is applied to the hydrogen ion implantation layer 13 of the bonding substrate 14 to peel off the silicon thin film 12B, and a silicon thin film transfer wafer 15 having the silicon thin film transferred onto the insulating substrate 11 is obtained. In order to give an impact to the ion-implanted layer, for example, it may be sprayed continuously or intermittently from the side surface of the wafer bonded with a jet of fluid such as gas or liquid.

  And this invention is characterized by the grinding | polishing process of grind | polishing the surface of the single crystal silicon thin film exposed by peeling about the silicon thin film transfer wafer manufactured by the said manufacturing method. Specifically, a single crystal silicon thin film, which is the surface of a silicon thin film transfer wafer, is brought into contact with a polishing cloth or a polishing pad, and the back surface of the silicon thin film transfer insulating wafer is made of a thin film material having a bending rigidity of 150 GPa or more in Young's modulus. In this method, the surface of the single crystal silicon thin film is polished with a polishing cloth or a polishing pad by pressing the silicon thin film transfer wafer from the back surface through contact with the backing pad.

Here, the characteristics of the manufacturing method according to the present invention will be described based on the example shown in FIG. In FIG. 1, a silicon thin film transfer wafer W has a single crystal silicon thin film W1 that is a surface to be polished brought into contact with a polishing cloth 1 (or a polishing pad), and a back surface W2 of the silicon thin film transfer insulating wafer is a backing pad 2. It is in a state of being in contact with. In this state, the silicon thin film transfer wafer is pressurized from the back surface W2 through the backing pad 2 as shown by the arrow in FIG. 1, and the surface of the single crystal silicon thin film W1 is polished with the polishing cloth 1.
The backing pad 2 may be a part of the polishing head 3 or may be integrated with the polishing head 3.
As the polishing cloth 1, it is possible to use what is usually used for polishing a wafer, and it is generally attached to the surface of the surface plate 4.
The surface of the single crystal silicon thin film W1 can be polished by rotating and driving the surface plate 4 on which the polishing pad 1 is stuck while the polishing head 3 is fixed. It is also possible to carry out by driving the polishing head 3 with the surface plate 4 fixed, and furthermore, it can also be carried out by driving the polishing head 3 while the surface plate 4 rotates. .
In the polishing, a guide ring 5 that holds the outer periphery of the silicon thin film transfer wafer W may be used in order to prevent the wafer W from shifting and to perform the polishing safely. Moreover, you may grind | polish using an abrasive | polishing agent slurry suitably in a grinding | polishing process.

In the present invention, the bending rigidity of the backing pad is set to 150 GPa or more in terms of Young's modulus. If the backing pad exhibits this degree of rigidity, the pressure applied by pressurization is appropriately averaged within the wafer surface, This is because the uneven distribution is eliminated and uniformized. In addition, the thin film material has a displacement on the order of μm in the backing pad in response to the pressurization, and the displacement of this extremely small amount of material becomes a cushion for cushioning. This is because it is possible to avoid problems such as film thickness fluctuations due to foreign matters sandwiched between the thin film transfer wafer and the polishing head. Here, a thin film is a film that exhibits different properties from a large lump by thinning, and even if it is a very hard material with a Young's modulus of 150 GPa or higher in bending rigidity, the form is a thin film. By doing so, a very small amount of material displacement may occur.
The flexural rigidity is preferably 150 GPa to 500 GPa in terms of Young's modulus, and this range is suitable in view of the uniform pressure distribution and the effect as a cushion for cushioning. If the Young's modulus exceeds 500 GPa, it will be difficult to process as a backing pad, and even a thin film material will not easily be displaced.

  Specifically, the backing pad is preferably made of a material selected from the group consisting of stainless steel (SUS), sapphire, and silicon carbide as a material that satisfies the Young's modulus. This is because it is a material that can exhibit an effect as a cushion for cushioning and uniforming the pressure distribution.

  In the manufacturing method concerning this invention, it is preferable that the thickness of a backing pad is 0.5 mm or more. If it is 0.5 mm or more, there is no problem in the bias of the pressure distribution due to pressurization, and a very small amount of displacement is possible. This is because it is possible to avoid problems such as film thickness fluctuations due to foreign matter sandwiched between them. The thickness of the backing pad is more preferably in the range of 0.5 mm to 2.0 mm from the viewpoint of pressure distribution and displacement due to pressurization.

The pressurization performed on the back surface of the silicon thin film transfer wafer via the backing pad is preferably pressurization by air pressure or pressurization by mechanical pressure. This is because if pressure is applied by air pressure, the pressure is uniformly applied to the back surface of the wafer through the backing pad, so that there is no problem in uneven pressure distribution. In addition, even in the case of mechanical pressure, if pressure is uniformly applied to the back surface of the wafer through the backing pad, there is no problem in uneven pressure distribution.
The pressurization by air pressure includes, for example, a pressurization method called airflow that allows air to flow from the back of the backing pad. The pressurization by mechanical pressure includes, for example, a method of pressurizing the back of the wafer. .

Next, a silicon thin film transfer wafer polishing apparatus according to the present invention will be described based on the example shown in FIG.
The present invention includes a surface plate 4 having a polishing cloth 1 for polishing a single crystal silicon thin film W1 on the surface of a silicon thin film transfer wafer W, and a backing that can come into contact with the back surface W2 of the silicon thin film transfer wafer W. A pad 2, a polishing head 3 that holds the silicon thin film transfer wafer W through the backing pad 2 and abuts the silicon thin film transfer wafer W on the polishing pad 1, and, as indicated by an arrow in FIG. And a pressing means (not shown) that presses the silicon thin film transfer wafer W from the back surface W2 through the polishing head 3 and presses it against the surface plate 4, and rotationally drives the surface plate 4 and / or drives the polishing head 3. The silicon thin film transfer wafer polishing apparatus has at least a drive mechanism (not shown) for polishing the silicon thin film transfer wafer W with the polishing cloth 1.

In the present invention, the backing pad is made of a thin film material having a bending rigidity of Young's modulus of 150 GPa or more. As described above, the bending rigidity of the backing pad is set to 150 GPa or more in terms of Young's modulus. If the backing pad exhibits such a rigidity, the pressure applied by the pressurization is appropriately averaged within the wafer surface, This is because the uneven distribution is eliminated and uniformized. In addition, the thin film material has a displacement on the order of μm in the backing pad in response to the pressurization, and the displacement of this extremely small amount of material becomes a cushion for cushioning. This is because it is possible to avoid problems such as film thickness fluctuations due to foreign matters sandwiched between the thin film transfer wafer and the polishing head. Here, a thin film is a film that exhibits different properties from a large lump by thinning, and even if it is a very hard material with a Young's modulus of 150 GPa or higher in bending rigidity, the form is a thin film. By doing so, a very small amount of material displacement may occur.
The flexural rigidity is preferably 150 GPa to 500 GPa in terms of Young's modulus, and this range is suitable in view of the uniform pressure distribution and the effect as a cushion for cushioning. If the Young's modulus exceeds 500 GPa, it will be difficult to process as a backing pad, and even a thin film material will not easily be displaced.

  Specifically, the backing pad is preferably made of a material selected from the group consisting of stainless steel (SUS), sapphire, and silicon carbide as a material that satisfies the Young's modulus. This is because it is a material that can exhibit an effect as a cushion for cushioning and uniforming the pressure distribution.

  In the polishing apparatus according to the present invention, the thickness of the backing pad is preferably 0.5 mm or more. If it is 0.5 mm or more, there is no problem in the bias of the pressure distribution due to pressurization, and a very small amount of displacement is possible. This is because it is possible to avoid problems such as film thickness fluctuations due to foreign matter sandwiched between them. The thickness of the backing pad is more preferably in the range of 0.5 mm to 20 mm from the viewpoint of pressure distribution and displacement due to pressurization.

  The pressurization performed on the back surface of the silicon thin film transfer wafer via the backing pad is preferably pressurization by air pressure or pressurization by mechanical pressure. This is because if pressure is applied by air pressure, the pressure is uniformly applied to the back surface of the wafer through the backing pad, so that there is no problem in uneven pressure distribution. In addition, even in the case of mechanical pressure, if pressure is uniformly applied to the back surface of the wafer through the backing pad, there is no problem in uneven pressure distribution.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited to an Example and a comparative example.
<Manufacture of single crystal silicon thin film transfer wafer>
Hydrogen ions were implanted from the surface of the single crystal silicon wafer with an oxide film to provide a hydrogen ion implanted layer, and then a plasma activation process was performed. Then, the surface of the silicon wafer and the surface of the handle wafer made of the SOQ wafer were bonded to obtain a bonded wafer. Subsequently, after performing heat treatment at 250 ° C. for 24 hours, mechanical peeling was performed at the ion implantation interface, and the hydrogen ion implantation layer was peeled off, thereby manufacturing a wafer to which the single crystal silicon thin film was transferred. Using the thus obtained single crystal silicon thin film transfer wafer (diameter 150 mm, silicon thin film thickness 280 nm, quartz substrate thickness 625 μm, initial in-plane film thickness variation 50 nm), polishing treatment was performed as follows. went.

<Polishing single crystal silicon thin film transfer wafer>
The single crystal silicon thin film to be polished of the silicon thin film transfer wafer was brought into contact with the polishing cloth, and the back surface of the silicon thin film transfer wafer was brought into contact with a backing pad made of the material shown in Table 1 and having a thickness of 0.75 mm. It was in a state. In this state, the silicon thin film transfer wafer was pressurized from the back surface thereof with a polishing pressure of 1.5 psi through a backing pad, and the surface of the single crystal silicon thin film was polished 100 nm with a polishing cloth.
As the polishing cloth, a cloth usually used for polishing a silicon thin film transfer wafer was used, which was attached to the surface of a surface plate and polished. The surface of the single crystal silicon thin film could be polished by rotating and driving a surface plate on which a polishing cloth was stuck with the polishing head fixed.
In order to prevent displacement of the silicon thin film transfer wafer, a guide ring that holds the outer periphery of the silicon thin film transfer wafer was used. An alkaline solution in which colloidal silica was dispersed was used as the abrasive slurry.

After polishing by the above method, 49 points in the surface of the silicon thin film transfer wafer were measured using an optical interferometer, and the in-plane film thickness variation was defined as the difference between the maximum value and the minimum value of the film pressure. An in-plane film thickness variation of 10 nm or less is one of the performance criteria, and it is empirically known that device identification is stabilized by being 10 nm or less. The results are shown in FIG.
As a result, in stainless steel, sapphire, and silicon carbide, which are materials having a Young's modulus of 150 or more, the in-plane film thickness variation was 10 nm or less, and good results were shown (FIG. 2, Examples 1 to 3). From this result, if a 1 mm thick thin film material with a bending rigidity of Young's modulus of 150 GPa or more is used as a backing pad, the pressure due to pressurization is appropriately averaged within the wafer surface, and the silicon thin film transfer wafer and the polishing head It was found that the in-plane film thickness variation can be controlled by not being affected by the film thickness fluctuation due to foreign matter sandwiched between them.
On the other hand, when a material whose bending stiffness is less than Young's modulus of 150 GPa is used as a backing pad, it is affected by pressure deviation due to pressurization and film thickness fluctuation due to foreign matter sandwiched between the silicon thin film transfer wafer and the polishing head. As a result, the in-plane film thickness variation was larger than 10 nm (FIG. 2, Comparative Examples 1 to 3).

  Based on the above results, considering that a material with a Young's modulus of 150 or more is suitable as a backing pad, we next examined the influence of the thickness of the backing pad on the in-plane film thickness variation based on stainless steel materials. did.

  A single crystal silicon thin film transfer wafer was polished under the same conditions as described above using a backing pad made of stainless steel. Here, the thickness of the backing pad was 0.2 mm to 3 mm. The results are shown in FIG.

From the results, if the backing pad thickness is 0.3 mm or more and 2.5 mm or less, the in-plane film thickness variation is about 10 nm or less, and if 0.5 mm or more and 2 mm or less, the in-plane film thickness variation is about 8 nm. (Fig. 3). Further, when the thickness of the backing pad is 0.2 mm, the in-plane film thickness variation exceeds 10 nm. This is presumably because the backing pad was excessively deformed, the pressure was not constant in the surface, and was affected by the film thickness variation, and the in-plane film thickness variation increased. The reason why the variation in film thickness tends to increase when the thickness of the backing pad exceeds 2 mm is considered to be due to the influence of film thickness variation due to foreign matter sandwiched between the wafer and the polishing head. From the overall results, it was found that the thickness of the backing pad is preferably 0.5 mm or more and 2.0 mm or less.
In general, it is known that the bending rigidity of an object is proportional to Young's modulus × (object thickness) ³ . From the above results, the Young's modulus of SUS × (the thickness of the object) ³ is between 23.5 and 1680 because the Young's modulus is 190 GPa to 210 GPa and the thickness of the object is 0.5 mm to 2 mm. Is presumed to be preferable.

  According to the present invention, since in-plane film thickness variation is stable, a silicon thin film transfer wafer capable of stabilizing device performance can be easily manufactured.

W silicon thin film transfer wafer W1 single crystal silicon thin film W2 silicon thin film transfer wafer back surface 1 polishing cloth 2 backing pad 3 polishing head 4 surface plate 5 guide ring 11 insulating substrate 11S surface of insulating substrate 12 single crystal silicon substrate 12B silicon thin film 12S Single crystal silicon ion implantation surface 13 Hydrogen implantation layer 14 Bonding substrate 15 Silicon thin film transfer wafer 101 Polishing head 102 Wafer D Wafer removed by polishing

Claims (9)

A hydrogen ion implantation step of implanting hydrogen ions from the surface of the single crystal silicon wafer and providing a hydrogen ion implantation layer in the single crystal silicon wafer;
A bonding step of bonding the surface of the single crystal silicon wafer and the surface of the handle wafer to obtain a bonded wafer;
A peeling step of peeling off the hydrogen ion implanted layer from the bonded wafer to obtain a wafer to which a single crystal silicon thin film is transferred,
A polishing step of polishing the surface of the single crystal silicon thin film exposed by peeling;
A method for producing a silicon thin film transfer wafer containing at least
The polishing step is
Contacting the single crystal silicon thin film, which is the surface of the silicon thin film transfer wafer, with a polishing cloth or a polishing pad;
The back surface of the silicon thin film transfer wafer is brought into contact with a backing pad made of a thin film material having a thickness of 0.5 mm to 2.0 mm and a bending rigidity of 150 GPa or more in Young's modulus,
Pressurizing the silicon thin film transfer wafer from the back surface through the backing pad,
A method for producing a silicon thin film transfer wafer, wherein the surface of the single crystal silicon thin film is polished with the polishing cloth or the polishing pad.   The method for producing a silicon thin film transfer wafer according to claim 1, wherein the backing pad is made of a material selected from the group consisting of stainless steel, sapphire, and silicon carbide. The pressure method of producing a silicon thin film transfer wafer according to claim 1 or claim 2, which is pressurized by air pressure. The pressure method of producing a silicon thin film transfer wafer according to claim 1 or claim 2, which is pressurized by mechanical pressure. The method for producing a silicon thin film transfer wafer according to any one of claims 1 to 4 , wherein the handle wafer is selected from the group consisting of a silicon wafer, a sapphire wafer, a quartz wafer, a silicon carbide wafer, and a glass wafer. A surface plate with a polishing cloth or polishing pad for polishing a single crystal silicon thin film on the surface of a silicon thin film transfer wafer,
A backing pad that can contact the back surface of the silicon thin film transfer wafer;
A polishing head for holding the silicon thin film transfer wafer via the backing pad and bringing the silicon thin film transfer wafer into contact with the polishing cloth;
A pressing means for pressing the silicon thin film transfer wafer from the back surface through the backing pad and the polishing head and pressing the wafer against the surface plate;
A driving mechanism for rotating the surface plate and / or driving the polishing head to polish the silicon thin film transfer wafer with the polishing cloth;
A silicon thin film transfer wafer polishing apparatus having at least
A polishing apparatus for a silicon thin film transfer wafer, wherein the backing pad is made of a thin film material having a thickness of 0.5 mm to 2.0 mm and a bending rigidity of 150 GPa or more in Young's modulus. The polishing apparatus for a silicon thin film transfer wafer according to claim 6 , wherein the backing pad is made of a material selected from the group consisting of stainless steel, sapphire, and silicon carbide. The polishing apparatus for a silicon thin film transfer wafer according to claim 6 or 7 , wherein the pressing means is means for pressing by air pressure. The polishing apparatus for a silicon thin film transfer wafer according to claim 6 or 7 , wherein the pressing means is means for pressing by mechanical pressure.

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