Coating processes – Coating by vapor – gas – or smoke – Mixture of vapors or gases utilized
Reexamination Certificate
2000-06-27
2004-04-27
Chen, Bret (Department: 1762)
Coating processes
Coating by vapor, gas, or smoke
Mixture of vapors or gases utilized
C427S099300, C427S255700, C427S255392
Reexamination Certificate
active
06726955
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of a semiconductor processing and more specifically to a method and apparatus for controlling the crystal structure of a silicon film.
2. Discussion of Related Art
In order to fabricate more complex and higher density integrated circuits such as microprocessors and memories, device features must be continually reduced. An important feature which must be reduced in order to increase device density is the polysilicon gate lengths and correspondingly the polysilicon thickness of MOS transistors. Present polysilicon deposition processes form polysilicon films
602
having large and columnar grains
604
as shown in FIG.
6
. As transistor gate lengths are shrunk to less than 0.18 microns the large and columnar grains
604
are beginning to play a critical role in the performance of the transistor. Dopants
606
which are subsequently added to the polysilicon film in order to reduce the resistance of the film utilize the grain boundaries
608
to diffuse throughout the polysilicon film
602
. Because in prior art processes the grains
604
are large and columnar dopant diffusion is restricted causing areas
610
of undoped polysilicon, especially at the polysilicon
602
/gate dielectric
612
interface. The lack of uniform distribution of dopants, known as poly depletion effects, detrimentally affects the performance of the fabricated transistor especially as a gate lengths decrease to below 0.18 microns.
Thus, what it desired a method of forming a polysilicon film with small and random grains so that narrow width gate length electrodes can be fabricated without suffering from poly depletion effects.
SUMMARY OF THE INVENTION
A method and apparatus for forming a polycrystalline silicon film. According to the present invention a process gas mix comprising a silicon source gas and a dilution gas mix is fed into a chamber wherein the dilution gas mix comprises H
2
and an inert gas. A polycrystalline silicon film is then formed from the process gas mix.
REFERENCES:
patent: 4374163 (1983-02-01), Isenberg
patent: 5064779 (1991-11-01), Hasegawa
patent: 5094885 (1992-03-01), Selbrede
patent: 5272096 (1993-12-01), De Fresart et al.
patent: 5324684 (1994-06-01), Kermani et al.
patent: 5389580 (1995-02-01), Miyasaka
patent: 5470619 (1995-11-01), Ahn et al.
patent: 5498904 (1996-03-01), Harata et al.
patent: 5786027 (1998-07-01), Rolfson
patent: 5798137 (1998-08-01), Lord et al.
patent: 6190961 (2001-02-01), Lam et al.
patent: 6227140 (2001-05-01), Kennedy et al.
patent: 3809101 (1989-09-01), None
patent: 61148815 (1986-07-01), None
patent: 61154025 (1986-07-01), None
patent: 61224312 (1986-10-01), None
patent: 0628644 (1994-12-01), None
patent: 2111630 (1972-06-01), None
patent: WO 0004574 (2000-01-01), None
International Search Report PCT/US 01/20102.
Chen Steven A.
Luo Lee
Sanchez Errol
Wang Shulin
Applied Materials Inc.
Blakely & Sokoloff, Taylor & Zafman
Chen Bret
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