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Improved Process for Forming Self Aligned Titanium Disilicide (Salicide)

IP.com Disclosure Number: IPCOM000122319D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Mann, RW: AUTHOR [+2]

Abstract

By initially annealing at temperature (T) where 700

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This is the abbreviated version, containing approximately 89% of the total text.

Improved Process for Forming Self Aligned Titanium Disilicide (Salicide)

      By initially annealing at temperature (T) where 700<T<900
degrees Celsius, titanium disilicide (TiSi2) is formed (where Ti and
Si are in contact) which has low and relatively stable resistivity
under subsequent heat treatment.  A treatment at this elevated
temperature for relatively short times, e.g., 15 seconds, does not
inhibit removal of unreacted Ti, as well as providing small
crystallites of a stable TiSi2 crystalline form.

      As in conventional Salicide processing, Ti is deposited by any
of several means onto a substrate comprised of silicon (Si) having
regions of bare Si and the remainder of the surface coated with SiO2
.  This new process uses an anneal in the usual nitrogen atmosphere
for a short time after the Ti deposition to immediately form stable
TiSi2 crystalline phase C54.  Unlike conventional processing, no
further heat treatment is required to obtain this stable structure.
However, the resistivity of the silicide formed in the new process is
relatively stable if exposed to subsequent heat treatment.  Also, the
silicide thus formed is stable and inert in the conventional Ti etch
removal process in which the Ti over an oxide or nitride is readily
removed.

      The new process results in lower resistivity TiSi2 which is
more stable to subsequent heat treatment and less susceptible to
degradation by silicide agglomeration and resultant variability in
electrical...