Novel InAs/(Al,Ga)Sb FET with direct gate-to-channel contact

A new type of FET has been fabricated in which the gate is in direct contact with the channel. There is no intervening charge separating layer. Instead, the separation of gate and channel carriers is achieved by using the staggered band alignment of InAs/(Al,Ga)Sb such that a p/sup +/ (Al,Ga)Sb gate layer is placed in direct contact with the n-type InAs channel. At 77 K the measured devices show both current gain and voltage gain, and a maximum transconductance of 500 mS/mm has been observed. >