Browse Prior Art Database

GALLIUM IMPLANT IN NMOS FOR SPEED IMPROVEMENT

IP.com Disclosure Number: IPCOM000024487D
Original Publication Date: 1980-Oct-31
Included in the Prior Art Database: 2004-Apr-02
Document File: 2 page(s) / 91K

Publishing Venue

Xerox Disclosure Journal

Abstract

Experiments have shown that gallium (Gal implanted in a field oxide (FO) is operative to diffuse through Silicon Dioxide (SiO ). The implantation of Ga into SiO The purpose of impfanting Ga and diffusing it under Si02 is to prevent an inversion layer forming at the P-type Si - SiOz interface. Currently, the industry standard is to use boron (B) as a dopant for this purpose.

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XEROX DISCLOSURE JOURNAL

GALLIUM IMPLANT IN NMOS FOR SPEED IMPROVEMENT U.S. Cl. 357/22 Anikara Iiangappan

Proposed Classification

Int. Cl. HOll 29/80

SOURCE OR DRAIN

SOURCE OR DRAIN

FIG la

FIG. lb

FIG. 20 FIG. 26

Experiments have shown that gallium (Gal implanted in a field oxide (FO) is operative to diffuse through Silicon Dioxide (SiO ). The implantation of Ga into SiO The purpose of impfanting Ga and diffusing it under Si02 is to prevent an inversion layer forming at the P-type Si - SiOz interface. Currently, the industry standard is to use boron
(B) as a dopant for this purpose. the underlying Si has to be doped before the Si02 is grown on the non-active fielc?irea. In this process, B diffuses considerably into Si. This diffusion of B into an active

offers several unique applications in Si k processing.

Since B has a very low diffusivity in SiO

Volume 5 Number 5 September/October 1980 539.

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GALLIUM IMPLANT IN NMOS FOR SPEED IMPROVEMENT (Cont'd)

area essentially reduces the active width in MOS devices using a p-type substrate. The technique of using a Ga implant after the FO is grown has the specific advantage of reducing the encroachment of depletion mode - N-channel MOS devices. This in turn results in faster operation of N-channel MOS depletion -

enhancement mode devices and an operation higher speed in the LSI circuitry. Another anticipated significant advantage of the Ga-implant for a chan...