Short channel fermi-threshold field effect transistors including drain field termination region and methods of fabricating same
US5698884A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 7, 1996 |
| Grant date | Dec 16, 1997 |
| Priority date | — |
| Expiry date | Feb 7, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/371
Abstract
A Fermi-FET includes a drain field termination region between the source and drain regions, to reduce and preferably prevent injection of carriers from the source region into the channel as a result of drain bias. The drain field terminating region prevents excessive drain induced barrier lowering while still allowing low vertical field in the channel. The drain field terminating region is preferably embodied by a buried counterdoped layer between the source and drain regions, extending beneath the substrate surface from the source region to the drain region. The buried counterdoped layer may be formed using a three tub structure which produces three layers between the spaced apart source and drain regions. The drain field terminating region may also be used in a conventional MOSFET. The channel region is preferably formed by epitaxial deposition, so that the channel region need not be counterdoped relative to the drain field terminating region. Higher carrier mobility in the channel may thereby be obtained for a given doping level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.