Reactive sputter cleaning of semiconductor wafer

DETAILED DESCRIPTION Accordingly, it is an object of the present invention to provide a method for improving the yield in the manufacturing of semiconductor wafers.
Another object of this invention is to decrease or eliminate rejected devices related to the overetching of sidewall oxide by a metal preclean.
It is an additional object to provide a new or improved cleaning procedure by eliminating hydrofluoric acid, or a similar wet etch, from the cleaning procedure of a metal preclean.
A further object of this invention is to decrease or eliminate rejected devices related to native oxide or residual oxide left prior to metal deposition.
A further object is to permit use of thin oxide sidewalls which improve device performance.
A still further object is to perform a metal preclean and a metal deposition in the same sputtering system.
The foregoing and other objects and advantages are achieved in the present invention which, as part thereof, makes use of a reactive sputter clean in which a mixture of freon (CF.
sub.
4) and argon are added to a typical sputter deposition system, activating the sputter system and etching residual oxide from select regions on a semiconductor wafer, stopping the flow of the freon to the sputter system after a predetermined time, and sputter depositing a metal on the semiconductor wafer.
The features and advantages of the invention will be apparent from the following, more detailed description of the preferred embodiment of the invention taken in conjunction with the accompanying drawings.