JPS62101024A - Epitaxial-growth wafer - Google Patents

Abstract

PURPOSE:To offset compressive force and expansion force, and to manufacture a wafer having no warpage by forming the same semiconductor thin-films on both surfaces of a substrate. CONSTITUTION:Silicon such as double-side polished silicon is used as a substrate 1, and a gallium-arsenic layer 2 is shaped onto both surfaces through an organic metallic decomposition vapor phase growth method. Accordingly, crystalline semiconductor thin-films cannot be formed onto both surfaces of the substrate by a device which has been used, but the thin-films can be shaped by employing an improved device in which a reaction gas flows on both surfaces of the substrate as shown in the figure.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to epitaxial growth wafers.

[Prior art and its problems]

Conventionally, epitaxial growth wafers having various single-layer or multilayer crystalline semiconductor thin films on various crystalline semiconductor substrates have been manufactured, and these epitaxial growth wafers are used to manufacture various electronic devices or optical devices. A chair is being made. In order to obtain the semiconductor thin film layer with good electrical properties, generally 5.
The semiconductor thin film layer is formed on the substrate surface at a temperature of 00°C or higher.

Conventionally, the semiconductor thin film layer was formed only on one side of the substrate, so when the thermal expansion coefficients of the substrate and the semiconductor thin film layer were different, the epitaxial growth wafer would warp when cooled to room temperature after forming the semiconductor thin film layer, causing the device to deteriorate. Various problems have occurred during the manufacturing process.

[Means to solve the problem]

In order to solve the above problems, the present invention forms semiconductor thin film layers on both sides of a substrate.

[For production]

In the conventional structure in which a semiconductor thin film layer was formed only on one side of the substrate, the cause of warpage in the epitaxially grown wafer was due to the difference in thermal expansion coefficient between the semiconductor thin film layer and the substrate, and the temperature at which the semiconductor thin film layer was formed and the room temperature. This is because compression or expansion force is generated in the semiconductor thin film layer with respect to the substrate due to the temperature difference between . Therefore, by forming the same semiconductor thin film on both sides of the substrate,
The compression or expansion forces cancel each other out, so that no warpage occurs in the epitaxially grown wafer.

〔Example〕

FIG. 1 shows an embodiment of the present invention. In this example, both sides were polished. For example, a silicon substrate 1 is used, and gallium/arsenic layers 2 are formed on both sides thereof by metal organic decomposition vapor phase epitaxy. Forming a crystalline semiconductor thin film on both sides of the substrate in this way was impossible with conventional equipment, so improvements were made to allow the reactive gas to flow on both sides of the substrate, for example, as shown in Figure 2. This is possible by using a device that

〔Effect of the invention〕

The present invention makes it possible to produce epitaxially grown wafers without warping.

Brief explanation of the east plane FIG. 1 is a cross-sectional view of an epitaxially grown wafer that is an embodiment of the present invention, and FIG. 2 is a schematic diagram of an apparatus for manufacturing the epitaxially grown wafer.
2 is a view of the device viewed from the side, and FIG. 2(b) is a cross-sectional view thereof.

l: silicon substrate, 2: gallium arsenic layer, 3: substrate,
4: Two substrate support stands, 5: Reaction tube, 6: Reaction gas, 7: Two substrate heating light sources, 8: Substrate heating reflector.

Claims (4)

[Claims] (1) Epitaxial growth in a wafer having a crystalline semiconductor thin film consisting of a single layer or multiple layers having a coefficient of thermal expansion different from that of the substrate on the surface of the crystalline semiconductor substrate, characterized in that the thin film layer is provided on both surfaces of the substrate. Uehua. (2) The epitaxial growth wafer according to claim 1, wherein the crystalline semiconductor substrate is made of silicon or germanium, and the crystalline thin film is made of a compound semiconductor. (3) The epitaxially grown wafer according to claim 2, wherein the compound semiconductor is gallium arsenide. (4) The epitaxial growth wafer according to claim 1, characterized in that a vapor phase growth apparatus is used in which a reactive gas flows on both sides of the substrate.