JP2007150017A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form semiconductor layers containing different components while suppressing contamination due to the component contained in the semiconductor layers. <P>SOLUTION: A semiconductor layer 11 and a protective film 12 are formed by selective epitaxial growth on the surface of a semiconductor wafer W1. After that, a resist pattern 13 for exposing the protective film 12 of the external periphery of the semiconductor wafer W1 is formed. The protective film 12 is etched using the resist pattern 13 as a mask, thereby eliminating the protective film 12 on the external periphery of the semiconductor wafer W1. The semiconductor layer 11 is etched using the resist pattern 13 and the protective film 12 as a mask, thereby eliminating the semiconductor layer 11 on the external periphery of the semiconductor wafer W1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device, and is particularly suitable for application to a method for preventing contamination of SiGe formed on a Si substrate.

Field effect transistors formed on an SOI substrate are attracting attention because of their ease of element isolation, latch-up freeness, and low source / drain junction capacitance. In particular, since a fully depleted SOI transistor can operate at low power consumption and at high speed and can be easily driven at a low voltage, research for operating the SOI transistor in a fully depleted mode has been actively conducted. Here, Non-Patent Document 1 discloses a method in which an SOI transistor can be formed at low cost by forming an SOI layer on a bulk substrate. In the method disclosed in Non-Patent Document 1, a Si / SiGe layer is formed on a Si substrate, and only the SiGe layer is selectively removed using the difference in etching rate between Si and SiGe. A cavity is formed between the Si substrate and the Si layer. Then, by performing thermal oxidation of Si exposed in the cavity, an SiO ₂ layer is buried between the Si substrate and the Si layer, and a BOX layer is formed between the Si substrate and the Si layer.
T.A. Sakai et al. “Separation by Bonding Si Islands (SBSI) for LSI Applications”, Second International GiGe Technology and Device Abstraction, pp. 230-231, May (2004)

  However, in the method disclosed in Non-Patent Document 1, when a Si / SiGe layer is formed on a Si substrate and Si / SiGe adheres to the outer peripheral portion or the back surface of the wafer, the Si / SiGe layer is used in the subsequent semiconductor manufacturing process. Peeled off from the wafer, causing the generation of particles and causing Ge contamination. In particular, when particles or Ge contamination occurs when forming the gate insulating film or the gate electrode, there is a problem that not only the manufacturing yield is lowered, but also the reliability of the LSI which has normally operated at the initial stage is deteriorated.

  Therefore, an object of the present invention is to provide a method for manufacturing a semiconductor device capable of forming a semiconductor layer on a semiconductor substrate while suppressing contamination due to generation of particles and components contained in the semiconductor layer. is there.

In order to solve the above-described problem, according to a method for manufacturing a semiconductor device according to one aspect of the present invention, a step of forming a semiconductor layer by selective epitaxial growth on a surface of a semiconductor wafer, and a step of forming the outer periphery of the semiconductor wafer And a step of selectively removing the formed semiconductor layer.
As a result, even when a semiconductor layer is formed on the surface of the semiconductor wafer, it is possible to execute the subsequent semiconductor manufacturing process after removing the semiconductor layer formed on the outer peripheral portion of the semiconductor wafer. For this reason, in the semiconductor manufacturing process of the semiconductor wafer on which the semiconductor layer is formed, the semiconductor layer can be prevented from being peeled off from the semiconductor wafer, and contamination caused by generation of particles or components contained in the semiconductor layer is suppressed. Therefore, the manufacturing yield can be improved and the reliability of the LSI manufactured on the semiconductor wafer can be improved.

According to the method for manufacturing a semiconductor device of one embodiment of the present invention, the step of forming a protective film on the semiconductor layer before selectively removing the semiconductor layer formed on the outer peripheral portion of the semiconductor wafer. Is further provided.
Thereby, when the semiconductor layer formed on the outer peripheral portion of the semiconductor wafer is selectively removed, damage to the semiconductor layer can be suppressed, and the generation of particles and the semiconductor can be suppressed while suppressing the deterioration of the quality of the semiconductor layer. Contamination caused by components contained in the layer can be suppressed.

The method for manufacturing a semiconductor device according to one aspect of the present invention further includes the step of scrubbing the semiconductor wafer after selectively removing the semiconductor layer formed on the outer periphery of the semiconductor wafer. It is characterized by that.
As a result, after selectively removing the semiconductor layer formed on the outer peripheral portion of the semiconductor wafer, the particles adhering to the semiconductor wafer can be removed, and then the subsequent semiconductor manufacturing process can be performed. Contamination due to components contained in the semiconductor layer can be suppressed.

In addition, according to the method of manufacturing a semiconductor device according to one aspect of the present invention, a step of forming a semiconductor layer by epitaxial growth on the entire surface of the semiconductor wafer and a semiconductor layer formed on the outer peripheral portion and the back surface of the semiconductor wafer are selected. And removing it.
Thereby, even when the semiconductor layer is formed on the entire surface of the semiconductor wafer, the semiconductor layer formed on the outer peripheral portion and the back surface of the semiconductor wafer can be removed and the subsequent semiconductor manufacturing process can be executed. For this reason, in the semiconductor manufacturing process of the semiconductor wafer on which the semiconductor layer is formed, the semiconductor layer can be prevented from being peeled off from the semiconductor wafer, and contamination caused by generation of particles or components contained in the semiconductor layer is suppressed. Therefore, it is possible to form a semiconductor layer on a semiconductor wafer by batch processing, improve the manufacturing yield, and improve the reliability of the LSI manufactured on the semiconductor wafer. Can be improved.

Further, even when the semiconductor layer is selectively epitaxially grown on the semiconductor wafer surface, the present invention is also applicable to the case where the semiconductor layer is formed on the outer peripheral edge of the wafer surface or at least a part of the wafer back surface in the epitaxial growth step. it can.
According to the method for manufacturing a semiconductor device of one embodiment of the present invention, a step of forming a semiconductor layer by epitaxial growth on the entire surface of the semiconductor wafer, a step of forming an insulating film on the semiconductor layer, and the semiconductor wafer A step of exposing the outer peripheral portion of the surface of the semiconductor wafer by selectively removing the semiconductor layer and the insulating film formed on the outer peripheral portion of the surface of the semiconductor wafer, and on the exposed surface of the outer peripheral portion of the surface of the semiconductor wafer A step of forming a sidewall covering the sidewall of the semiconductor layer on the surface of the semiconductor wafer, and etching the semiconductor layer using the insulating film and the sidewall as a mask, And a step of removing the semiconductor layer formed on the back surface.

  Thereby, even when the semiconductor layer is formed on the entire surface of the semiconductor wafer, the semiconductor layer formed in the effective chip region of the semiconductor wafer is prevented from being etched and formed on the outer peripheral portion and the back surface of the semiconductor wafer. The semiconductor layer can be removed. Therefore, it is possible to form a semiconductor layer on a semiconductor wafer by batch processing, and it is possible to prevent the semiconductor layer from peeling off from the semiconductor wafer in the subsequent semiconductor manufacturing process. It becomes possible to suppress contamination caused by components contained in the layer.

The method for manufacturing a semiconductor device according to one embodiment of the present invention further includes a step of diffusing impurities in the semiconductor layer before etching the semiconductor layer using the insulating film and the sidewall as a mask. It is characterized by that.
This makes it possible to increase the etching rate of the semiconductor layer, and prevents the semiconductor layer formed in the effective chip region of the semiconductor wafer from being etched even when the semiconductor layer is formed on the entire surface of the semiconductor wafer. Meanwhile, the semiconductor layer formed on the outer peripheral portion and the back surface of the semiconductor wafer can be efficiently removed.

According to the method for manufacturing a semiconductor device of one embodiment of the present invention, the semiconductor wafer has a Si substrate, and the semiconductor layer has a single-layer structure of Si, a single-layer structure of SiGe, or a stacked structure of SiGe / Si. It is characterized by.
This makes it possible to form a single crystal Si layer or a single crystal SiGe layer with good crystal quality on the Si substrate, and to improve the characteristics of the LSI formed on the Si substrate. Further, by forming a SiGe / Si stacked structure on the Si substrate, it is possible to selectively remove only the SiGe layer using the difference in etching rate between Si and SiGe without using an SOI substrate. An SOI structure can be formed on the Si substrate.

Hereinafter, a semiconductor device manufacturing method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1A is a plan view showing a configuration of a wafer according to the first embodiment of the present invention, and FIGS. 1B to 1D are methods for manufacturing a semiconductor device according to the first embodiment of the present invention. FIG.
In FIG. 1A, the semiconductor wafer W1 is provided with an effective chip region R1 from which one semiconductor chip can be cut and an outer peripheral region R2 from which one semiconductor chip cannot be cut. Yes.

  1B, after forming the semiconductor layer 11 on the surface of the semiconductor wafer W1 by selective epitaxial growth, the protective film 12 is formed on the semiconductor layer 11 by a method such as thermal oxidation, sputtering, or CVD. As a material of the semiconductor wafer W1, for example, Si, Ge, SiGe, SiC, SiSn, PbS, GaAs, InP, GaP, GaN, or ZnSe can be used. In addition, as the first semiconductor layer 11, for example, a single layer structure such as Si, Ge, SiGe, SiC, SiSn, PbS, GaAs, InP, GaP, GaN, or ZnSe or a stacked structure of different semiconductors can be used. Here, by using a Si substrate as the semiconductor wafer W1 and a stacked structure of SiGe / Si as the semiconductor layer 11, only the SiGe layer can be selectively removed using the difference in etching rate between Si and SiGe. The SOI structure can be formed on the Si substrate without using the SOI substrate. Further, as the protective film 12, for example, a silicon oxide film or a silicon nitride film can be used. Also, an elevated source / drain structure can be formed by selectively epitaxially growing a Si substrate as the semiconductor wafer W1 and a SiGe or Si layer as the semiconductor layer 11 in the source / drain regions of the MOSFET.

Next, as shown in FIG. 1C, a resist pattern 13 that exposes the protective film 12 on the outer peripheral portion of the semiconductor wafer W1 is formed by using a photolithography technique. The resist pattern 13 can be a pattern that covers the effective chip region R1 of FIG. 1A and exposes the outer peripheral region R2.
Next, as shown in FIG. 1D, the protective film 12 is etched using the resist pattern 13 as a mask to remove the protective film 12 on the outer peripheral portion of the semiconductor wafer W1. Then, the semiconductor layer 11 is etched using the resist pattern 13 and the protective film 12 as a mask to remove the semiconductor layer 11 on the outer peripheral portion of the semiconductor wafer W1, and then the resist pattern 13 is removed. Note that the method for etching the semiconductor layer 11 may be either dry etching or wet etching. For example, when SiGe is removed as the semiconductor layer 11, dry etching using a chlorine-based gas or a mixed gas of oxygen and fluorine as an etching gas may be used, or hydrofluoric nitric acid, hydrofluoric nitric acid, hydrofluoric acetic acid, or ammonia Wet etching using excess water as an etchant may be used.

  Thereby, even when the semiconductor layer 11 is formed on the surface of the semiconductor wafer W1, it is possible to execute the subsequent semiconductor manufacturing process after removing the semiconductor layer 11 formed on the outer peripheral portion of the semiconductor wafer W1. . For this reason, in the semiconductor manufacturing process of the semiconductor wafer W1 on which the semiconductor layer 11 is formed, it is possible to prevent the semiconductor layer 11 from being peeled off from the semiconductor wafer W1, resulting from generation of particles and components contained in the semiconductor layer 11. Therefore, the manufacturing yield can be improved, and the reliability of the LSI manufactured on the semiconductor wafer W1 can be improved.

  Note that the semiconductor wafer 11 may be scrubber cleaned after the semiconductor layer 11 formed on the outer periphery of the semiconductor wafer W1 is selectively removed. Thereby, after selectively removing the semiconductor layer 11 formed on the outer peripheral portion of the semiconductor wafer W1, particles adhering to the semiconductor wafer W1 can be removed, and then a subsequent semiconductor manufacturing process can be executed. Occurrence of contamination and contamination due to components contained in the semiconductor layer 11 can be suppressed.

FIG. 2 is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to a second embodiment of the present invention.
In FIG. 2A, the semiconductor layer 21 is formed on the entire surface of the semiconductor wafer W2 by epitaxial growth. Even when the semiconductor layer 21 is selectively epitaxially grown on the surface of the semiconductor wafer W2, even when the semiconductor layer 21 is formed in at least a partial region of the outer peripheral edge of the wafer surface or the wafer back surface in the epitaxial growth step. This manufacturing method can be applied. In addition, by using the Si substrate as the semiconductor wafer W2 and the stacked structure of SiGe / Si as the semiconductor layer 21, it is possible to selectively remove only the SiGe layer using the difference in etching rate between Si and SiGe. An SOI structure can be formed on a Si substrate without using an SOI substrate.

  Next, as shown in FIG. 2B, an insulating film 22 is formed on the semiconductor layer 21 by a method such as thermal oxidation, sputtering, or CVD. For example, a silicon oxide film or a silicon nitride film can be used as the insulating film 22. And the resist pattern 23 which covers the effective chip area | region of the semiconductor wafer W2 is formed by using a photolithographic technique. Then, the insulating film 22 is etched using the resist pattern 23 as a mask to remove the insulating film 22 in the outer peripheral region of the semiconductor wafer W2, so that the effective chip region of the semiconductor wafer W2 is covered with the insulating film 22.

Next, as shown in FIG. 2C, the semiconductor layer 21 in the outer peripheral region of the semiconductor wafer W2 is removed by performing anisotropic etching of the semiconductor layer 21 using the resist pattern 23 and the insulating film 22 as a mask.
Next, as shown in FIG. 2D, after removing the resist pattern 23, an insulating film is deposited on the entire surface of the semiconductor wafer W2 by a method such as CVD. Then, by performing anisotropic etching of the insulating film deposited on the semiconductor wafer W2, it is disposed on the exposed surface of the outer peripheral region of the surface of the semiconductor wafer W2, and the side wall of the semiconductor layer 21 on the surface of the semiconductor wafer W2 is removed. Covering sidewalls 24 are formed.

  Next, as shown in FIG. 2E, the semiconductor layer 21 is removed by etching the semiconductor layer 21 using the insulating film 22 and the sidewalls 24 as a mask, thereby removing the semiconductor layer 21 formed on the end and back surface of the semiconductor wafer W2. To do. Here, by forming the sidewall 24 on the sidewall of the semiconductor wafer W2, it is possible to prevent the semiconductor layer 21 formed in the effective chip region from being etched from the side.

  The method for etching the semiconductor layer 21 may be either dry etching or wet etching. For example, when SiGe is removed as the semiconductor layer 21, dry etching using a chlorine-based gas or a mixed gas of oxygen and fluorine as an etching gas may be used, or hydrofluoric nitric acid, hydrofluoric nitric acid, or hydrofluoric acid. Alternatively, wet etching using ammonia-hydrogen peroxide as an etchant may be used.

Next, as shown in FIG. 2F, the insulating film 22 and the sidewalls 24 that cover the semiconductor layer 21 are removed.
Thereby, even when the semiconductor layer 21 is formed on the entire surface of the semiconductor wafer W2, the outer peripheral region of the semiconductor wafer W2 is prevented while the semiconductor layer 21 formed in the effective chip region of the semiconductor wafer W2 is prevented from being etched. Further, the semiconductor layer 21 formed on the back surface can be removed. Therefore, for example, the semiconductor layer 21 can be formed on the semiconductor wafer W2 by batch processing, and the semiconductor layer 21 can be prevented from peeling off from the semiconductor wafer W2 in the subsequent semiconductor manufacturing process. It is possible to suppress contamination caused by the generation of particles and components contained in the semiconductor layer 21.

  Note that an impurity such as B or P may be diffused into the semiconductor layer 21 before the semiconductor layer 21 is etched using the insulating film 22 and the sidewalls 24 as a mask. As a result, the etching rate of the semiconductor layer 21 can be increased, and even when the semiconductor layer 21 is formed on the entire surface of the semiconductor wafer W2, the semiconductor layer 21 formed in the effective chip region of the semiconductor wafer W2 is etched. The semiconductor layer 21 formed on the outer peripheral region and the back surface of the semiconductor wafer W2 can be efficiently removed while preventing this. Alternatively, the semiconductor wafer W2 may be scrubber cleaned after the semiconductor layer 21 formed on the outer periphery of the semiconductor wafer W2 is selectively removed.

The figure which shows the manufacturing method of the semiconductor device which concerns on 1st Embodiment of this invention. The figure which shows the manufacturing method of the semiconductor device which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  W1, W2 semiconductor wafer, R1 effective chip region, R2 outer peripheral region, 11, 21 semiconductor layer, 12 insulating film 22, insulating film, 13, 23 resist pattern, 24 sidewall

Claims (7)

Forming a semiconductor layer by selective epitaxial growth on the surface of the semiconductor wafer;
And a step of selectively removing a semiconductor layer formed on the outer periphery of the semiconductor wafer.   2. The method of manufacturing a semiconductor device according to claim 1, further comprising a step of forming a protective film on the semiconductor layer before selectively removing the semiconductor layer formed on the outer peripheral portion of the semiconductor wafer. .   The method for manufacturing a semiconductor device according to claim 1, further comprising a step of scrubber cleaning the semiconductor wafer after selectively removing a semiconductor layer formed on an outer peripheral portion of the semiconductor wafer. Forming a semiconductor layer by epitaxial growth on the entire surface of the semiconductor wafer;
And a step of selectively removing a semiconductor layer formed on the outer peripheral portion and the back surface of the semiconductor wafer. Forming a semiconductor layer by epitaxial growth on the entire surface of the semiconductor wafer;
Forming an insulating film on the semiconductor layer;
Selectively exposing the semiconductor layer and the insulating film formed on the outer peripheral portion of the surface of the semiconductor wafer to expose the outer peripheral portion of the surface of the semiconductor wafer;
A step of forming a sidewall that is disposed on an exposed surface of an outer peripheral portion of the surface of the semiconductor wafer and covers a sidewall of the semiconductor layer on the surface of the semiconductor wafer;
And a step of removing the semiconductor layer formed on the end and back surface of the semiconductor wafer by etching the semiconductor layer using the insulating film and the sidewall as a mask. Method.   6. The method of manufacturing a semiconductor device according to claim 5, further comprising a step of diffusing impurities into the semiconductor layer before etching the semiconductor layer using the insulating film and the sidewall as a mask.   7. The semiconductor device according to claim 1, wherein the semiconductor wafer has a Si substrate, and the semiconductor layer has a single-layer structure of Si, a single-layer structure of SiGe, or a stacked structure of SiGe / Si. Manufacturing method.

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