Browse Prior Art Database

Enhanced Metal-Silicide Formation by Low Energy Bombardment

IP.com Disclosure Number: IPCOM000040487D
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 3 page(s) / 128K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR [+2]

Abstract

A technique is described whereby the formation of thinner and more uniform metal silicides are produced so as to be able to reduce the size of silicon devices, as used in VLSI structures. The concept provides a process of lowering the time-temperature required to form three silicides from thin films of metal deposited on silicon substrates by means of pretreatment of the silicon substrates and/or concurrent bombardment of the depositing film with low energy ion beams. The use of metal silicides as an intermediate layer between contact metallurgy and the device silicon is readily recognized in VLSI structures. Silicides are normally formed by depositing a metal layer and annealing the device at an elevated temperature in order to enable the metal to react with the silicon for the silicide formation.

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 53% of the total text.

Page 1 of 3

Enhanced Metal-Silicide Formation by Low Energy Bombardment

A technique is described whereby the formation of thinner and more uniform metal silicides are produced so as to be able to reduce the size of silicon devices, as used in VLSI structures. The concept provides a process of lowering the time-temperature required to form three silicides from thin films of metal deposited on silicon substrates by means of pretreatment of the silicon substrates and/or concurrent bombardment of the depositing film with low energy ion beams. The use of metal silicides as an intermediate layer between contact metallurgy and the device silicon is readily recognized in VLSI structures. Silicides are normally formed by depositing a metal layer and annealing the device at an elevated temperature in order to enable the metal to react with the silicon for the silicide formation. High

(Image Omitted)

energy ion beam irradiation of the films after deposition has been shown to increase the number of sites at which the initial formation of silicide occurs. Increasing the number of nucleation sites for the formation of silicides reduces the roughening of the surface which can result during the silicide formation. A minimum time-temperature cycle is required for the formation of a laterally continuous silicide to form from the initial nucleation sites. The growth of silicide normal to the plane of the film requires that a sufficient thickness of silicon be allocated to the formation of the silicide. An increase in the number of nucleation sites from which the silicide forms will reduce the thickness required for a continuous silicide. The concept described herein provides a process to reduce the time-temperature required to form the silicide and reduces the roughening of the silicide surface. The process steps for the enhanced metal silicide f...