Zilog, Inc.

Jack Berg

Gregory Hindman

Peter N Manos, Ii

John Rule

The present invention concerns a method of preventing the staining and voiding in an aluminum layer. This staining and voiding was found to be caused by cross-contamination of nitrogen from other processing steps in a multi-chambered wafer processing device. The present invention avoids the staining and voiding by introducing a pumping-out step of an aluminum layer sputtering chamber to remove some of the nitrogen from the aluminum layer deposition chamber before sputtering the aluminum layer onto the silicon wafer. Alternately, the temperature of the aluminum layer deposition step can be reduced to 310.degree. C. or less to prevent the staining or voiding.

Method of eliminating metal voiding in a titanium nitride/aluminum

The present invention concerns a method for contact metallization on a semiconductor where a contact hole is formed in an interlevel dielectric layer down to a doped silicon region on the silicon substrate, and then the wafer is placed into a sputtering chamber where titanium is sputtered onto the wafer. A titanium nitride layer is sputtered on top of the titanium layer in the contact hole. This invention saves time and money, because the titanium nitride layer depositing and titanium layer forming steps can occur in the same chamber without forming the boro-phosphorous silicate glass layer in between. The titanium layer reacts with the silicon to form a silicide layer at the time of the sputtering in a hot deposition or in later steps that supply heat to the wafer for a period of time. Optionally, an additional titanium layer can be formed on top of the titanium nitride layer to clean off the titanium target used to sputter the titanium and titanium nitride layers on the wafer. A metal layer including aluminum is then formed on top of the titanium layer or the titanium nitride layer to form the contact metallization with the doped silicon region in the semiconductor.

Ti/TiN/Ti contact metallization

The present invention concerns a method for doping a polysilicon layer with phosphorous in which phosphorous oxychloride is supplied to the silicon wafer near the beginning of the oven temperature ramping of the silicon wafer. By introducing the phosphorous oxychloride earlier than in prior art methods, the present invention can reduce the poly rho and poly rho sigma of the doped polysilicon layer. Alternatively, the root DT of the diffusion of the doped material in the doped silicon region on the silicon wafer can be reduced, which helps to maintain the junction depth of the doped silicon region.

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Boise, ID, United States of America

Jack Berg