Compound semiconductor device epitaxial growth substrate, semiconductor device, and manufacturing method thereof

Abstract

A compound semiconductor device epitaxial growth substrate, wherein a semiconductor substrate, a substrate protective layer made of a material that is different from the material of the substrate, a middle layer for making separation of the semiconductor substrate and a compound semiconductor device layer possible, and a compound semiconductor device layer that is formed through epitaxial growth are layered in this order; and a semiconductor device which uses the compound semiconductor device layer that is gained by separating the semiconductor substrate, the substrate protective layer and the middle layer from this compound semiconductor device epitaxial growth substrate; as well as manufacturing methods for these.

Description

[0001] This nonprovisional application is based on Japanese Patent Application No. 2004-262854 filed with the Japan Patent Office on Sep. 9, 2004, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to reduction in cost of a compound semiconductor device epitaxial growth substrate which is manufactured through epitaxial growth, and in particular, to reduction in cost of a semiconductor device such as a high efficiency multijunction-type compound solar cell. In addition, the present invention relates to reduction in cost of a semiconductor substrate that is used for epitaxial growth by reusing the substrate. [0004] 2. Description of the Background Art [0005] In the case of a semiconductor device that needs a large amount of epitaxial films having a large area, such as a solar cell, it is required that the material cost is as low as possible. Concerning the material cost, t...

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Benefits of technology

[0013] In accordance with this compound semiconductor device epitaxial growth substrate of the present invention, the element layer and the semiconductor substrate can be separated at the middle lay

Problems solved by technology

Concerning the material cost, the ratio of the cost of the substrate is large, and therefore, ideas for reducing the material cost by means of techniques such as reusing the substrate after peeling the substrate from the element have been put forth for a long time.

According to this method, however, the pores remain on the surface of the substrate, and therefore, flattening or cleaning through surface processing becomes necessary.

According to this method, however, the surface of the substrate is damaged, and therefore, flattening or cleaning through surface processing becomes necessary.

According to this method, however, a layer that has deteriorated due to a chemical change remains on the surface of the substrate, and therefore, flattening or cleaning through surface processing, again, becomes necessary.

As described above, any method which is known as a conventional technology for reusing a substrate has a problem where the surface of the substrate becomes coarse or polluted after the separation, and requires processing for flattening or cleaning, such as polishing on the surface of the substrate, lapping or the like.

Therefore, cost becomes high, due to surface processing, and in addition, a problem arises, where the number of times that use is possible is reduced due to reduction in the thickness of the substrate, and the yield is reduced due to cracking of the substrate.

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