Browse Prior Art Database

Growth Rate Enhancement for High Rate, Low Temperature Selective/ Blanket Tungsten

IP.com Disclosure Number: IPCOM000122346D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 48K

Publishing Venue

IBM

Related People

Joshi, RV: AUTHOR [+2]

Abstract

Described is a fabrication method which is designed to enhance the growth rate of selective tungsten at low temperatures for use in integrated circuit technology.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 77% of the total text.

Growth Rate Enhancement for High Rate, Low Temperature Selective/
Blanket Tungsten

      Described is a fabrication method which is designed to enhance
the growth rate of selective tungsten at low temperatures for use in
integrated circuit technology.

      Selective tungsten has been found to provide effective
metallization via filling, contact metallurgy, etc. However, prior
art required temperatures above 500~C and produced large quantities
hydrofluoric acid (HF) which degraded the junction qualities and
produced worm holes and tunnels.  The concept described herein
provides a fabrication process that avoids the degradation problems
as well as improves the growth rate, adhesion and stress.

      The process involves the use of disilane.  The gas chemistries
can be used as follows:
         7WF + 6SiF4 + 18HF
     At higher temperatures:
         7WF6 + 3Si2H6--->7SELECTIVEW + 6SiF4 + 18HF
     At lower temperatures:
         4WF6 + 3Si2H6 --> 4W + 6SiF4 + 9H2

      The ratios of Si2H6/WF6 should be less than 2.  The process
e is workable for cold wall reactors having selective tungsten
deposition capability.  Disilane is more effective than silane
because of its reactivity and it contains two atoms of silicon which
generate SiF4, such that the HF is minimized.  Also, the
decomposition temperature of disilane is much lower than the silane
decomposition temperature.  As a result, the process works below
400~C at high...