Monolithic integration of enhancement- and depletion-mode AlGaN/GaN HFETs

US7972915B2 · kind B2 · utility

Assignee

• The Hong Kong University of Science and Technology

Inventors

• Jing Chen · Hong Kong, CN
• Yong Cai · Fuzhou, CN
• Kei May Lau · Kowloon, CN

Key dates

• Filing date: Nov 29, 2006
• Grant date: Jul 5, 2011
• Expiry date: Nov 11, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/8503

Abstract

A method for and devices utilizing monolithic integration of enhancement-mode and depletion-mode AlGaN/GaN heterojunction field-effect transistors (HFETs) is disclosed. Source and drain ohmic contacts of HFETs are first defined. Gate electrodes of the depletion-mode HFETs are then defined. Gate electrodes of the enhancement-mode HFETs are then defined using fluoride-based plasma treatment and high temperature post-gate annealing of the sample. Device isolation is achieved by either mesa etching or fluoride-based plasma treatment. This method provides a complete planar process for GaN-based integrated circuits favored in high-density and high-speed applications.