Abstract: This invention pertains to more sensitive and more stable electronic devices which can sense electrical and magnetic fields. The devices are characterized by InAs channels confined on both sides thereof by a wide band gap AlSb material; protective layers above the AlSb material; modulation doping above the AlSb material; and layers of the InAs channel material containing 1 to 99 mol percent antimony, with the channel material being deposited in the form of alternating monolayers of InSb and InAs, of a ternary mixture of InAsSb.

Abstract: Heterostructure field-effect transistors (HFETs) and other electronic devs are fabricated from a series of semiconductor layers to have reduced impact ionization. On to a first barrier layer there is added a unique second subchannel layer having high quality transport properties for reducing impact ionization. A third barrier layer having a controlled thickness to permit electrons to tunnel through the layer to the subchannel layer is added as a spacer for the fourth main channel layer. A fifth multilayer composite barrier layer is added which has at least a barrier layer in contact with the fourth channel layer and on top a sixth cap layer is applied. The device is completed by adding two ohmic contacts in a spaced apart relationship on the sixth cap layer with a Schottky gate between them which is formed in contact with the fifth barrier layer.

Abstract: An electronic device characterized by a GaAs substrate and a base disposed n the substrate, the base comprising InAs channel layer, AlSb layer above the channel layer, In.sub.x Al.sub.1-x As.sub.y Sb.sub.1-y layer containing at least In, Al, and As disposed above the AlSb channel layer, InAs cap layer disposed above and in contact with the In.sub.x Al.sub.1-x As.sub.y Sb.sub.1-y layer disposed below the InAs channel layer and in contact with the substrate, p.sup.+ GaSb layer disposed within the AlSb layer, Schottky gate with a pad disposed on and in contact with the In.sub.x Al.sub.1-x As.sub.y Sb.sub.1-y layer, at least one ohmic contact disposed on the InAs cap layer, and a trench extending through the base to the substrate isolating the gate bonding pad from the device and providing a gate air bridge which prevents contact between the gate and the InAs layer.

Abstract: A heterojunction device, and a method for producing the device. A gate air bridge is formed at the mesa sidewall between the active region and the gate bonding pad to lower the gate leakage current. The device has a double recessed gate to reduce local fields in the vicinity of the gate. The fabrication method uses dielectric intermediate and final passivation layers to optimize the double-recess profile and control the extension of the high-field region between the gate and the drain. This combination increases the breakdown potential of the device, but minimizes the effective gate length of the device, preserving high frequency performance.