| 摘要 |
PURPOSE:To improve mobility, and to obtain an element functioning at superhigh speed by alternately laminating InAsSbP, a lattice constant thereof agrees with that of an InAs substrate and which has a predetermined composition, on the substrate in fixed thickness. CONSTITUTION:InAs with d1 thickness and InAsxSbyP1-x-y (x=1-3.2y), thickness thereof is d2 and the lattice constant thereof is equal to InAs, are alternately laminated on the InAs substrate, and d1 and d2 shall be approximately 10-300Angstrom . In this case, electrons are confined in the InAs layers in case of an N type semiconductor. When normal InAs, the mobility of electrons is limited by the concentration of impurities in a low temperature region (approximately 100 deg.K), and when the concentration of electrons becomes high (10<17>cm<-3> or higher) the mobility slows down because the concentration of a corresponding donar also increases. When N type impurities of N>=10<18> are added and laminated to the InAsSbP, the electrons of the InAsSbP ooze to the InAs with low potential. Accordingly, the concentration of electrons becomes high even when the concentration of the donar of the InAs is low, and the mobility increases. |
