JPH05144727A - Manufacture of heteroepitaxial wafer - Google Patents

Abstract

PURPOSE:To improve the warp of a substrate due to the difference of a coefficient of thermal expansion or due to the difference of a lattice constant and to improve a stress exerted on an epitaxial film without increasing the number of processes and appratuses to be used in a manufacturing process wherein a heteroepitaxial growth operation is executed. CONSTITUTION:In a process, a substance 2 whose coefficient of thermal expansion is equal to that of a substance 4 to be grown is applied in advance to a susceptor 1 on which a semiconductor-substrate wafer 3 is set, the semiconductor-substrate wafer 3 is then placed on the susceptor 1 and a heteroepitaxial growth operation is executed. In the process, the substance 2 which has been applied to the susceptor 1 is applied to the rear of the semiconductor-substrate wafer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heteroepitaxial wafer, and more particularly to a method for manufacturing a heteroepitaxial wafer in which a semiconductor different from a semiconductor substrate wafer is epitaxially crystal-grown.

[0002]

2. Description of the Related Art When performing heteroepitaxial growth on a semiconductor substrate wafer, the substrate is warped due to a difference in thermal expansion coefficient or a difference in lattice constant, stress is applied to the heteroepitaxial crystal film, and the epitaxial film is deteriorated. A crack etc. will occur.

As a method for solving such a problem, a substance having a coefficient of thermal expansion and an elastic modulus equal to those of an epitaxial growth layer to be grown on the surface of a semiconductor substrate wafer and exerting the same effect on the semiconductor substrate wafer is used as a semiconductor. The problem is solved by adhering it to the back surface of the substrate wafer (JP-A-62-92,428). In the growth method of heteroepitaxially growing GaAs, which is a compound semiconductor, on a silicon wafer by MOCVD or MBE, the problem due to the difference in thermal expansion coefficient and the difference in lattice constant is sputtered on the back surface of the silicon wafer 21 as shown in FIG. A SiO ₂ film 22 by a method (Japanese Patent Laid-Open No. 62-
196, 813), or the SiN film 22 is attached (Japanese Patent Application Nos. 62-28,114 and 62-69165).
It is solved by doing. Further, as shown in FIG. 3, a groove 32 is formed on the back surface of the epitaxial substrate 31 by dicing or etching in a direction perpendicular or parallel to the orientation flat (Japanese Patent Application No. Sho 6-62).
2-171, 112) overcomes the above problems.

[0004]

In the prior art as described above, SiO ₂ or Si is formed on the back surface of the semiconductor substrate wafer.
Since it is necessary to attach a substance completely different from the epitaxial film such as N, it becomes necessary to use a device different from the device used for growing the epitaxial film of the compound semiconductor. Processes other than epitaxial growth are required. That is, a problem arises in that extra steps and devices are required when manufacturing a heteroepitaxial substrate.

For example, when the semiconductor substrate wafer is a silicon wafer and the material for epitaxial growth is GaAs, the conventional technique uses SiO ₂ or Si by the CVD method.
As the process of attaching the N film to the back surface of the silicon wafer, first, (1) cleaning the silicon wafer, (2) setting the silicon wafer in the CVD device, (3) vapor deposition of SiO ₂ or SiN, (4) silicon The wafer is taken out, and at this time, the CVD device simultaneously deposits SiO _{2 on} both sides of the wafer.
Alternatively, if SiN is to be vapor-deposited at the same time, after the above steps, (5) apply a resist to the SiO ₂ or SiN film on the back surface, (6) bake the wafer to solidify the resist (5), 7) S on the surface of the silicon wafer
Steps such as removing the iO ₂ or SiN film, (8) removing the resist on the back surface of the silicon wafer, and (9) cleaning the silicon wafer necessary before GaAs epitaxial growth are added. Further, not only the process but also the device to be used requires, in addition to the epitaxial growth device, a device for depositing a SiO ₂ or SiN film and a device for transporting a silicon wafer as a minimum.

In the present invention, the problems of the prior art, such as the process and the apparatus used, are solved without losing the point that the warpage of the substrate and the stress applied to the epitaxial film due to the difference in the thermal expansion coefficient and the difference in the lattice constant solved by the prior art are improved. The aim is to improve the increase.

[0007]

SUMMARY OF THE INVENTION In the manufacturing method for heteroepitaxially growing a semiconductor different from a semiconductor substrate wafer on a semiconductor substrate wafer, the above-described objects are to be obtained by preliminarily growing a material and thermal expansion on a susceptor for setting the semiconductor substrate wafer. After depositing substances having the same coefficient, in the step of placing the semiconductor substrate wafer on the susceptor and performing heteroepitaxial growth, the substance deposited on the susceptor is attached to the back surface of the semiconductor substrate wafer. This is achieved by the manufacturing method.

[0008]

According to the present invention, before the heteroepitaxial growth step, a substance having a thermal expansion coefficient similar to that of a substance to be heteroepitaxially grown on a susceptor for setting a semiconductor substrate wafer in a device for heteroepitaxial growth, or the same compound semiconductor, Or, for example, G
aAs, InGaAs, InGaAsP, InAs, A
By depositing at least one selected from the group consisting of 1 GaAs and AlAs in advance, the substance deposited on the susceptor is re-evaporated in the subsequent step of heteroepitaxial growth, and a semiconductor substrate wafer or a silicon wafer is obtained. As a result, the same or the same material with the same thermal expansion coefficient will be attached to the front and back surfaces of the wafer, improving the deterioration of the film quality due to the warpage of the substrate and the generation of stress and the occurrence of cracks, etc. However, it is possible to increase the number of steps by which the above substances are previously attached on the susceptor in the same apparatus.

The semiconductor substrate wafer used in the present invention is, for example, a silicon wafer, and the material for heteroepitaxial growth is, for example, a compound semiconductor or, for example, GaAs or InGaA.
s, InGaAsP, InAs, AlGaAs and A
1As and the like. The device used is MOC.
A VD apparatus (organic metal chemical vapor deposition apparatus) is suitable.

[0010]

1 (a) to 1 (e) are explanatory views of steps for explaining an embodiment of the present invention. Hereinafter, description will be given with reference to the drawings.

In this embodiment, GaAs is epitaxially grown on a silicon wafer by MOCVD.

First, as shown in FIG. 1A, only the susceptor for setting a wafer is transferred from the preparation chamber to the growth chamber, and polycrystalline GaAs is deposited on the susceptor at 650 ° C. which is the actual growth temperature of GaAs. Coating as shown in 1 (b). At this time, the polycrystalline GaAs is the single crystal GaAs grown epitaxially on the surface of the silicon wafer.
The same tensile stress as that of GaAs on the front surface is applied to the back surface of the silicon wafer.

Next, the susceptor is returned to the preparation chamber, and a silicon wafer which has been subjected to necessary cleaning is set as shown in FIG. 1 (c). Then, the susceptor is moved to the growth chamber.

Next, the step of epitaxially growing a GaAs single crystal on the surface of the silicon wafer is started. First, a silicon wafer is placed in an H ₂ and AsH ₃ atmosphere at 85 ° C.
Wash at a high temperature of about 0 ° C. At this time, as shown in FIG. 1C, the polycrystal GaAs deposited on the susceptor is deposited on the back surface of the silicon wafer. When the silicon wafer, which was almost flat at 850 ° C., was cooled to the GaAs growth temperature of 650 ° C., due to the difference in thermal expansion coefficient between silicon and polycrystalline GaAs, as shown in FIG. Along the convex. And in this state,
GaAs is epitaxially grown on the surface of the silicon wafer as shown in FIG. 1E, and after the growth is completed, the temperature is lowered to room temperature. At this time, since the surface is subjected to a tensile stress due to the single crystal GaAs, as shown in FIG. 1 (f), the warpage can be improved in the silicon wafer obtained by epitaxially growing the obtained GaAs.

[0015]

As described above, according to the present invention,
Neither a sputtering apparatus nor a CVD apparatus for depositing the SiO ₂ or SiN film on the back surface of the wafer, which is required in the prior art, is required. Moreover, the number of steps to be increased can be simplified. Further, not only is the process simple, but when a compound semiconductor is heteroepitaxially grown on a silicon wafer, the compound semiconductor has a larger thermal expansion coefficient and a larger lattice constant than silicon. In the present invention, when the epitaxial growth is performed on the silicon wafer, the surface of the silicon wafer is convex as shown in FIG. 1D, so that the lattice constant of the surface of the silicon wafer widens and approaches that of GaAs. The epitaxially grown film is relatively subjected to compressive stress at the interface between silicon and GaAs, as compared with a film that is already epitaxially grown on a flat silicon wafer. Can be relaxed,
Substrate warpage can also be improved.

[Brief description of drawings]

1A to 1E are drawings for explaining an embodiment of the present invention.

FIG. 2 is a drawing for explaining a conventional heteroepitaxial growth method.

FIG. 3 is a drawing for explaining another conventional heteroepitaxial growth method. 3A is a view of the wafer as seen from the back surface, and FIG. 3B is a cross-sectional view of the wafer.

[Explanation of symbols]

 1 ... Susceptor, 2 ... Polycrystalline GaAs, 3 ... Silicon wafer, 4 ... Single crystal GaAs.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Aiji Jyosei 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Nippon Steel Corporation Advanced Technology Research Laboratories

Claims (3)

[Claims] 1. A manufacturing method for heteroepitaxially growing a semiconductor different from a semiconductor substrate wafer on a semiconductor substrate wafer, wherein a substance having a thermal expansion coefficient equivalent to that of a substance to be grown in advance is attached onto a susceptor for setting the semiconductor substrate wafer. After that, in the step of placing the semiconductor substrate wafer on the susceptor and performing heteroepitaxial growth,
A method for manufacturing a hetero-epitaxial wafer, wherein the substance deposited on the susceptor is deposited on the back surface of a semiconductor substrate wafer. 2. The method for producing a hetero-epitaxial wafer according to claim 1, wherein the substance to be heteroepitaxially grown and the substance to be previously deposited on the susceptor are compound semiconductors. 3. The compound semiconductor is GaAs or InGaA.
s, InGaAsP, InAs, AlGaAs and A
The method for producing a heteroepitaxial wafer according to claim 1 or 2, wherein the heteroepitaxial wafer is at least one selected from the group consisting of 1As.