Growing a heterostructure on a conductive substrate, the channel carrier de
nsity can be controlled by an applied gate voltage to the substrate. We mad
e InAs/Al/GaSb single-quantum wells using n- and p-type InAs substrates as
a back-gate. The devices perform well and the gate-leakage characteristics
are better for the n-type substrates than for the p-type substrates. (C) 20
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