High electron mobility in indium-rich pseudomorphic In/sub x/Ga/sub 1-x/As/In/sub 0.52/Al/sub 0.48/As structures grown by MBE on InP

High electron mobility pseudomorphic In/sub x/Ga/sub 1-x/As/InAlAs heterostructures have been fabricated on InP for a wide range of In composition and growth temperatures. Both mobility and carrier concentrations can be increased by increasing the indium content in the channel up to x=0.75. The highest performance has been obtained with x=0.75 for a growth temperature of 500/spl deg/C, when adapted growth conditions or growth interruptions are used to reduce the interface roughness. The electron mobility of such a structure reaches 14,500 cm/sup 2//V.s at 300 K and 101,000 cm/sup 2//V.s at 77 K for a two-dimensional electron gas concentration of 2.4 10/sup 12/ cm/sup -2/.<
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