Gallium arsenide crystal substrate

• Main Authors: Higuchi, Yasuaki, Morishita, Masanori, Hagi, Yoshiaki, Takayama, Hidetoshi
• Format: Patent
• Language: English
• Published: 09.08.2022
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

A gallium arsenide crystal substrate has a diameter not smaller than 150 mm and not greater than 205 mm and a thickness not smaller than 300 μm and not greater than 800 μm and includes any of a flat portion and a notch portion. In any of a first flat region and a first notch region, when an atomic concentration of silicon is not lower than 3.0×1016 cm−3 and not higher than 3.0×1019 cm−3, the gallium arsenide crystal substrate has an average dislocation density not lower than 0 cm−2 and not higher than 15000 cm−2, and when an atomic concentration of carbon is not lower than 1.0×1015 cm−3 and not higher than 5.0×1017 cm−3, the gallium arsenide crystal substrate has an average dislocation density not lower than 3000 cm−2 and not higher than 20000 cm−2.