Semiconductor device manufacturing: process – Coating with electrically or thermally conductive material – To form ohmic contact to semiconductive material
Patent
1997-07-29
1999-08-17
Quach, T. N.
Semiconductor device manufacturing: process
Coating with electrically or thermally conductive material
To form ohmic contact to semiconductive material
438657, 438683, 438908, H01L 21283
Patent
active
059407336
ABSTRACT:
Described is an improved polysilicon/tungsten silicide (WSi.sub.x) composite layer formed over an integrated circuit structure on a semiconductor wafer and characterized by improved step coverage and non tungsten-rich tungsten:silicon ratio of the WSi.sub.x layer, and a method of forming same. A doped layer of polysilicon is formed in a first deposition chamber over an integrated circuit structure previously formed on a semiconductor substrate and a capping layer of undoped polysilicon is then deposited in the first deposition chamber over the doped polysilicon layer. The substrate is then transferred from the first deposition chamber into a second deposition chamber without exposing the surface of the polysilicon layer to an oxidizing media. The desired tungsten silicide layer is then formed in the second deposition chamber onto undoped polysilicon capping layer, using a gaseous source of tungsten such as WF6, and dichlorosilane (DCS) as the source of silicon, without the formation of the undesirable tungsten-rich tungsten silicide layer characteristic of the prior art. The undoped polysilicon capping layer may then be doped, after the formation of the tungsten silicide layer, by subsequently heating the structure sufficiently to cause the dopant in the doped polysilicon layer to migrate into the undoped polysilicon layer thereon. Such heating may be carried out in a separate annealing step, but preferably is carried out in situ as a part of the subsequent processing of the integrated circuit structure being formed on the substrate.
REFERENCES:
patent: 4584760 (1986-04-01), Okazawa
patent: 4737474 (1988-04-01), Price et al.
patent: 4966869 (1990-10-01), Hillman et al.
patent: 4977104 (1990-12-01), Swada et al.
patent: 4992391 (1991-02-01), Wang
patent: 5130266 (1992-07-01), Huang et al.
patent: 5141892 (1992-08-01), Beinglass
patent: 5147820 (1992-09-01), Chittipeddi et al.
patent: 5182627 (1993-01-01), Chen et al.
patent: 5223456 (1993-06-01), Malwah
patent: 5256894 (1993-10-01), Shino
patent: 5332692 (1994-07-01), Saitoh
Hara, T., et al., "Tungsten Silicide Films . . . " J.Electrochem.Soc., vol. 136, No. 4, Apr. 1989, pp. 1177-1180.
Wolf, S., et al., Silicon Processing, vol. 1, Lattice Press, 1986, pp. 175-182.
Beinglass, I, et al., "Integrated System for Deposition of Polysilicon and WSix Films", Microelectronic Engineering, vol. 25, Aug. 1994, pp. 201-208.
"Method For Suppressing Diffusion of Dopant From Doped Polysilicon to Silicide", IBM Tech. Disc. Bull., vol. 32, No. 6A, Nov. 1989, pp. 206-207.
"Process for forming Tungsten Silicide with good adhesion to doped polycrystalline silicon", Research Disclosure, May 1988, p. 279.
Beinglass, Israel, "Integrating Polysilicon and Tungsten Silicide Deposition", Electronics Engineer, Mar., 1994, pp. 108-109 & 112-113.
Beinglass Israel
Srinivas Ramanujapuram A.
Applied Materials Inc.
Quach T. N.
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