COMPOSITE SUBSTRATE, SEMICONDUCTOR DEVICE, AND METHOD OF MANUFACTURING THEM

• Main Authors: MATSUO MIE, KAWASAKI ATSUKO
• Format: Patent
• Language: English; Japanese
• Published: 10.08.2017
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SEMICONDUCTOR DEVICES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PROBLEM TO BE SOLVED: To provide a composite substrate capable of reducing manufacturing failures of a compound semiconductor layer.SOLUTION: According to an embodiment, a composite substrate comprises: a first single crystal layer; a polycrystal layer provided on the whole surface of the first single crystal layer; and a second single crystal layer bonded with the polycrystal layer. A linear expansion coefficient of the polycrystal layer is larger than that of the second single crystal layer, and smaller than that of a compound semiconductor layer that can be provided on the second single crystal layer via a buffer layer.SELECTED DRAWING: Figure 1 【課題】化合物半導体層の製造不良を低減することが可能な複合基板を提供する。【解決手段】実施形態によれば、複合基板は、第１の単結晶層と、第１の単結晶層の全表面に設けられた多結晶層と、多結晶層に接合された第２の単結晶層と、を備える。多結晶層の線膨張係数は、第２の単結晶層の線膨張係数よりも大きくて、第２の単結晶層の上にバッファ層を介して設けることが可能な化合物半導体層の線膨張係数よりも小さい。【選択図】図１