Low pressure anisotropic etch process for tantalum silicide or t

Details Low pressure anisotropic etch process for tantalum silicide or t Low pressure anisotropic etch process for tantalum silicide or t

1991-01-02

1992-11-03

Hearn, Brian E.

Adhesive bonding and miscellaneous chemical manufacture

Delaminating processes adapted for specified product

Delaminating in preparation for post processing recycling step

156643, 156646, 156662, 156664, H01L 2100

Patent

active

051604078

ABSTRACT:
A low pressure process is described for the anisotropic etching of a titanium or tantalum silicide layer formed over a polysilicon layer on a gate oxide layer, and then masked. The etch process is carried out at a low pressure of about 10 milliTorr to about 30 milliTorr using Cl.sub.2 and HBr etching gases, preferably only Cl.sub.2 at the etching gas, to etch the silicide without undercutting the mask layer. In a preferred embodiment, etch residues are also eliminated by the use of only Cl.sub.2 as the etching gas in the low pressure etch step. In the most prefferred embodiment, any bulges which might otherwise remain in the sidewalls of the underlying polysilicon layer, are also eliminated by using only HBr as the etching gas in the over-etch step, which is highly selective to oxide to protect the underlying gate oxide layer; resulting in an anisotropic etch of both the titanium/tantalum silicide and polysilicon layers, without leaving etch residues on the wafer surface.

REFERENCES:
patent: 4473436 (1984-09-01), Beinvogl
patent: 4668338 (1987-05-01), Maydan et al.
patent: 4778563 (1988-10-01), Stone
patent: 4784720 (1988-11-01), Douglas
patent: 4785962 (1988-11-01), Toshima
patent: 4842683 (1989-06-01), Cheng et al.
patent: 4844767 (1989-07-01), Okudaira et al.
patent: 4951601 (1990-08-01), Maydan et al.
patent: 5007982 (1991-04-01), Tsou
patent: 5021121 (1991-06-01), Groechel et al.
patent: 5035768 (1991-07-01), Mu et al.
patent: 5036590 (1991-07-01), Amini et al.
"Precision 5000 Etch: Tungsten Silicide Process Capability"; Etch News Bulletin; Applied Materials, Inc.; vol. VII; No. 1, Spring 1990.
L. Y. Tsou; "Highly Selective Reactive Ion Etching of Polysilicon with Hydrogen Bromide"; J.E.S. Oct. 1989; vol. 136; No. 10; abstract (only).

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