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AssigneeBell Telephone Laboratories, Incorporated
InventorsHyman J. Levinstein, Shyam P. Murarka, Ashok K. Sinha
Estimating the term…
In order to form MOSFET structures, a cobalt layer (16) is deposited and sintered, at about 400.degree. C. to 500.degree. C., on a patterned semiconductor wafer having exposed polycrystalline (14) or monocrystalline (11) silicon portions, as well as exposed oxide (15 or 25) portions. The cobalt reacts with exposed surfaces of the silicon portions and forms thereat such compounds as cobalt monosilicide (CoSi) or di-cobalt silicide (C0.sub.2 Si), or a mixture of both. The unreacted cobalt is selectively removed, as by selective etching in a suitable acid bath. A heat treatment at about 700.degree. C. or more, preferably in an oxidizing ambient which contains typically about 2 percent oxygen, converts the cobalt compound(s) into relatively stable cobalt disilicide (CoSi.sub.2). Subsequently, deposition of an in situ doped layer (33) of polycrystalline silicon (polysilicon) on the cobalt disilicide contacting the monocrystalline silicon portions--followed by gettering, deposition of a layer (34) of aluminum, and standard etch-patterning of the aluminum and polysilicon layers--completes the metallization of the desired MOSFET structures on the silicon wafer.
A method for fabricating cobalt disilicide electrode metallization contacts for a semiconductor integrated circuit including heating a cobalt silicide layer overlying in contact with exposed silicon portions of a patterned silicon wafer to a temperature of at least 700.degree. C., whereby said layer is converted into a layer essentially of cobalt disilicide, and forming a layer of silicon dioxide on said layer of cobalt disilicide.
In a method for fabricating a silicon device:
In a method for fabricating an insulated gate field effect transistor, the steps for fabricating gate electrode metallization comprising:
Dependencies are inferred from the claim text.