US 5,311,045 A · Field effect devices with ultra-short gates

Abstract

The present invention is a method for making field effect devices, such as a field effect transistors, having ultrashort gate lengths so low as five hundred angstroms or less. In accordance with the invention the gate structure is grown vertically on a substrate by thin film deposition so that the length dimension of the gate is perpendicular to a major surface of the substrate. An edge of the gate-containing substrate is exposed, and the structure comprising the source, drain and channel is grown on the edge. Using this approach, field effect devices with precisely controlled gate lengths of less than 100 angstroms are achievable. Moreover the active regions of the device can be immersed within semiconductor material so that surface properties do not deteriorate device performance.

Claims4

Dependent claims

A field effect device comprising:

a gate comprising a first quantum well layer containing a two dimensional electron gas, said layer having a thickness of less than about 500 angstroms;
first and second spacer layers of non-conductive material disposed on either side of said gate;
a source and drain comprising a second quantum well layer containing a two dimensional electron gas, said second quantum well layer disposed transverse to said gate so that the gate thickness extends in the direction between the source and the drain, and a third spacer layer of non-conductive material spacing said second quantum well layer from said first quantum well layer.

Dependencies are inferred from the claim text.

Facts

Application

07/997,816Filed 29 Dec 1992 · division

Priority

15 Aug 1991

Granted

10 May 1994

Term ends

Not estimatedThe source records don’t support an estimate.

Classification9 codes

H10D 30/021
Manufacture or treatment: of FETs having insulated gates [IGFET]
H10D 30/015
Manufacture or treatment: of FETs having heterojunction interface channels or heterojunction gate electrodes, e.g. HEMT
H10D 30/4732
Having confinement of carriers by multiple heterojunctions, e.g. quantum well HEMT: using Group III-V semiconductor material
H10D 30/871
FETs having Schottky gate electrodes, e.g. metal-semiconductor FETs [MESFET]: vertical FETs having Schottky gate electrodes

Field effect devices with ultra-short gates

Life of this patent

Field effect devices with ultra-short gates

Life of this patent

Abstract

Claims4