Method for forming a microwave field effect transistor with high operating voltage
US6867078B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2003 |
| Grant date | Mar 15, 2005 |
| Priority date | — |
| Expiry date | Nov 19, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/411
Abstract
A microwave field effect transistor (10) has a high conductivity gate (44) overlying a double heterojunction structure (14, 18, 22) that has an undoped channel layer (18). The heterojunction structure overlies a substrate (12). A recess layer that is a not intentionally doped (NID) layer (24) overlies the heterojunction structure and is formed with a predetermined thickness that minimizes impact ionization effects at an interface of a drain contact of source/drain ohmic contacts (30) and permits significantly higher voltage operation than previous step gate transistors. Another recess layer (26) is used to define a gate dimension. A Schottky gate opening (42) is formed within a step gate opening (40) to create a step gate structure. A channel layer (18) material of InxGa1−xAs is used to provide a region of electron confinement with improved transport characteristics that result in higher frequency of operation, higher power density and improved power-added efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.