SEMICONDUCTOR CRYSTAL SUBSTRATE, INFRARED DETECTION DEVICE, OPTICAL SEMICONDUCTOR DEVICE, THERMOELECTRIC CONVERSION ELEMENT, METHOD FOR MANUFACTURING SEMICONDUCTOR CRYSTAL SUBSTRATE, AND METHOD FOR MANUFACTURING INFRARED DETECTION DEVICE

摘要

[Problem] To provide a semiconductor crystal substrate in which dislocation and lattice defects in an InAs/GaSb superlattice structure are reduced. [Solution] The problem is solved by a semiconductor crystal substrate comprising a crystal substrate with a major surface inclined from a (001) plane, and a superlattice structure layer formed by alternately stacking a first superlattice forming layer and a second superlattice forming layer on the major surface of the crystal substrate, characterized in that: the first superlattice forming layer is formed of a Ga_1-x1In_x1As_y1Sb_1-y1(0 ≤ x1 ≤ 0.1, 0 ≤ y1 ≤ 0.1) layer, wherein the value of standard deviation with respect to an average value of an atomic step width in a direction in which a surface of the first superlattice forming layer is inclined (standard deviation/value of the average value) is not less than 0 and not more than 0.20; and the second superlattice forming layer is formed of a Ga_1-x2In_x2As_y2Sb_1-y2(0.9 ≤ x2 ≤ 1, 0.9 ≤ y2 ≤ 1) layer, wherein the value of standard deviation with respect to an average value of an atomic step width in a direction in which a surface of the second superlattice forming layer is inclined (standard deviation/value of the average value) is not less than 0 and not more than 0.40.