Browse Prior Art Database

Gated Tunnel Diode

IP.com Disclosure Number: IPCOM000050564D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Fowler, AB: AUTHOR [+2]

Abstract

A semiconductor structure with a split, essentially abutting gate over a substrate in the dimensions and conditions for quantum mechanical tunneling will provide a gated tunnel diode.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Gated Tunnel Diode

A semiconductor structure with a split, essentially abutting gate over a substrate in the dimensions and conditions for quantum mechanical tunneling will provide a gated tunnel diode.

The structure of Fig. 1 can be made by growing an oxide with a step and evaporating a gate metal perpendicularly to the wafer.

The structure of Fig. 2 can be made by using polysilicon or polysilicon + silicides for the gate. Gate 1 can be oxidized, and a second gate 2 then deposited. When the structure is taken down to low temperature so that the substrate acceptor or donor ions are frozen out, the substrate becomes an insulator. Then one gate can be biased positive to give an n inversion layer, and the other gate negative to give an accumulated p layer. A two-dimensional n-p junction will form at the edge between the two gates. The bands at the surface of the substrate will be as shown in Fig. 3.

In operation, when a bias is placed between the n+ and p+ contacts, current can only flow by the tunneling of electrons from the inversion layer to the accumulation layer. If the n+ side is biased negatively enough (aproximately 1.2
V), conduction to the p-side conduction band is possible. This structure has the properties of a tunnel junction with the level of "p-or n-ness" adjustable using the two gates. At low temperatures, it will turn off completely for biases of a few tenths of a volt to about 1.2 V.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text...