Browse Prior Art Database

Partially Ion Implanted MOSFET

IP.com Disclosure Number: IPCOM000089756D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Jones, HJ: AUTHOR [+2]

Abstract

The density of large-scale integration (LSI) circuits employing metal oxide semiconductor field-effect transistor (MOSFET) devices is improved by minimizing device sizes to the extent that photolithographic tools can resolve shapes and devices maintain their performance. The latter is of importance since the circuit performance is related to device characteristics.

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Partially Ion Implanted MOSFET

The density of large-scale integration (LSI) circuits employing metal oxide semiconductor field-effect transistor (MOSFET) devices is improved by minimizing device sizes to the extent that photolithographic tools can resolve shapes and devices maintain their performance. The latter is of importance since the circuit performance is related to device characteristics.

Much has been written about the effect of short channels on MOSFET characteristics. It has been established that the device turn-on voltage is a strong function of device channel length and that drain-to-source voltages also effect the turn-on voltage for short devices. From the circuit designer's point of view, the dependency of device turn-on voltage on drain-to-source bias is undesirable for certain applications because the device is in the saturated region and no longer operates as a constant current source.

A device is disclosed which can overcome this problem and has certain other features which can be used advantageously. It will be shown that the disclosed device can be fabricated using conventional processing, and in fact is most suited for depletion-mode MOSFET technologies.

The proposed device employs the principle that detrimental short channel effects can be reduced if the source 1/drain 2 junctions are shallow. In the figure, for the drain region 2, the shallow junction can be simulated by ion-implanting an extension 6 in part of the channel C next to the dr...