Browse Prior Art Database

Rewritable IGFET Read Only Store

IP.com Disclosure Number: IPCOM000074875D
Original Publication Date: 1971-Jun-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Grochowski, EG: AUTHOR

Abstract

The problem of electrically addressing a general X-Y array of devices fusion of either device or metallization pattern yielding identity by closing the junction of X-Y lines. This addressing (or writing) is permanent.

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Rewritable IGFET Read Only Store

The problem of electrically addressing a general X-Y array of devices fusion of either device or metallization pattern yielding identity by closing the junction of X-Y lines. This addressing (or writing) is permanent.

The described writable-rewritable circuit has far more general applications. The device used is a standard isolated-gate field-effect transistor circuit array, as shown in A. In B, with zero of positive gate bias, with respect to source and drain, an inversion layer is established which allows current to flow between all X and Y lines and the circuit reads "one". This inversion layer is shown in C. When a negative potential is applied to the gate under temperatures 200 - 400 degrees C for silicon, ion transport occurs away from the interface minimizing both the inversion layer and source-drain conductance. The result is shown in D. In this way an open circuit X to Y, or "Zero", is written. By selectively biasing areas of the circuit at elevated temperatures, a write sequence could be applied. By applying a positive bias to these, the sequence may be reversed and the circuit erased for rewriting. A small heating element could be bonded to the chip for field writing and rewriting.

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