| Popis: |
We have grown heterostructures based on low band-gap channels of Ga x In 2−x Sb ( x =0.5) and InAs x Sb 1−x ( x =0.4−1) alloys, and characterized be closely lattice them using Hall measurements. For barrier layers, we used Al x In 1−x Sb( x =1−0.5), with a composition chosen to matched to the channel layers, Ga x In 1- x Sb and InAs x Sb 1−x . We also grew a Al x Ga 1−x As /GaAs y Sb 1−y /GaAs pseudomorphic heterostructure, which is an analog of the In x Ga 1−x As pseudomorphic MODFET. In the case of Al x In 1−x Sb/ Ga x In 1−x Sb and Al x In 1−x Sb/InAs x Sb 1−x heterostructures, the barrier layers were undoped but we observed two-dimensional electron densities of about 7×10 11 to 2×10 12 cm −2 at 300 K. For the AlSb/InAs and Al 0.7 In 0.3 Sb/Ga 0.7 In 0.3 Sb heterostructures, the 300 K mobilities were 24,000 and 3000 cm 2 /V⋯s, respectively. Mobilities for the Al x In 1−x Sb/InAs x Sb 1−x heterostructures were around 12,000 cm 2 /V⋯s. Hall measurements on the Al x Ga 1−x As/GaAs y Sb 1−y /GaAs heterostructures indicated 2D electron densities of 3×10 12 cm −2 and mobilities of 3,000 cm 2 /V⋯s. These results indicate the potential of the Al x In 1−x Sb/InAs x Sb 1−x ( x =0.4) heterostructures to be used as high-speed MODFETs and of the Al x Ga 1−x As/GaAs y Sb 1−y /GaAs heterostructures to be used as power MODFETs. |
