Enhancement mode device

US6452221B1 · kind B1 · utility

Assignee

• TRW Limited · US

Inventors

• Richard Lai · Redondo Beach, US
• Ronald W. Grundbacher · Hermosa Beach, US
• Yaochung Chen · Rancho Palos Verdes, US
• Michael E. Barsky · West Hollywood, US

Key dates

• Filing date: Sep 21, 2000
• Grant date: Sep 17, 2002
• Expiry date: Sep 21, 2020

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/4755

Abstract

An enhancement mode FET device (10) that employs a strained N-doped InAlAs charge shield layer (22) disposed on an intrinsic InAlAs barrier layer (20). A gate metal electrode (38) of the FET device (10) is controllably diffused through a recess (36) into the shield layer (22) to the barrier layer (20). The resulting enhancement mode device (10) provides an excellent Schottky barrier with a high barrier height that inhibits undesirable surface depletion effects through charge shielding by the shield layer (22) in the regions between the recess edge and the gate metal. Minimizing surface depletion effects makes the device more robust by making the surface less sensitive to processing conditions and long-term operation effects.