Integrated cobalt silicide process for semiconductor devices

A method of forming cobalt silicide on a semiconductor substrate comprising the steps of:

• providing a mainframe having a continuous vacuum, said mainframe having a cleaning chamber and a metal deposition chamber;
• introducing a semiconductor substrate having a surface, a portion of said surface having silicon thereon and a portion of said surface having an insulator thereon, said surface further having an oxide thereover;
• removing said oxide from said semiconductor surface within said cleaning chamber;
• heating said semiconductor substrate;
• depositing a cobalt layer on said heated semiconductor substrate over the silicon and insulator portions within said metal deposition chamber;
• and
• annealing said semiconductor substrate having cobalt disposed thereon to form cobalt silicide on said substrate surface by heating said semiconductor substrate having cobalt thereon at a constant rate to a temperature of about 575° C. and subsequently ramping said temperature down at said constant rate to about 20° C., thereby forming cobalt silicide only over portions of said semiconductor substrate surface having said silicon surface with cobalt thereover, while the cobalt remains unreacted over the insulator portion.

A method of forming cobalt silicide on desired portions of a semiconductor substrate comprising the steps of:

• providing a mainframe having a continuous vacuum, said mainframe having a cleaning chamber and a metal deposition chamber;
• introducing a semiconductor substrate into the continuous vacuum of said mainframe, said semiconductor substrate having a surface, a portion of said surface having silicon thereon and a portion of said surface having an insulator thereon, said surface further having an oxide thereover;
• removing said oxide from said semiconductor surface within said cleaning chamber using nitrogen fluoride;
• depositing a cobalt layer on said semiconductor substrate over the silicon and insulator portions by vapor sputtering within said metal deposition chamber, wherein said semiconductor substrate is heated to a temperature ranging from about 20° C. to 300° C. and depositing said cobalt over said heated semiconductor substrate up to about 300 Å;
• annealing said semiconductor substrate having cobalt disposed thereon to form cobalt silicide said substrate surface by heating said semiconductor substrate having cobalt thereon at a constant rate of 10° C./second to a temperature of about 575° C. and subsequently ramping said temperature down at said constant rate to about 20° C., thereby forming a cobalt silicide over portions of said semiconductor substrate surface having said silicon surface with cobalt thereover, while the cobalt remains unreacted over the insulator portion;
• and
• etching and removing the unreacted cobalt, thereby forming cobalt silicide only over portions of said semiconductor substrate surface having said silicon surface with cobalt thereover.