Method for forming semiconductor device structure with metal-semiconductor compound layer

A method for forming a semiconductor device structure, comprising:

• forming an isolation structure in a semiconductor substrate;
• forming a semiconductor strip structure over the semiconductor substrate, wherein the semiconductor strip structure extends across a first active region in the semiconductor substrate and extends over the isolation structure, the semiconductor strip structure has a first doped region and a spacing region connected to the first doped region, the first doped region extends across the first active region, and the spacing region is over the isolation structure;
• converting an upper portion of the spacing region into a disorder region;
• and
• forming a metal silicide layer over the semiconductor strip structure to cover the first doped region and the spacing region.

A method for forming a semiconductor device structure, comprising:

• forming an isolation structure in a semiconductor substrate to surround a first active region of the semiconductor substrate;
• forming a gate structure over the semiconductor substrate, wherein the gate structure extends across the first active region and the isolation structure;
• forming a first doped region and a spacing region in the gate structure, wherein the spacing region is adjacent to the first doped region, the first doped region extends across the first active region, and the spacing region is over the isolation structure;
• performing an implantation process over the spacing region and the first doped region to convert upper portions of the spacing region and the first doped region into a continuous disorder region;
• and
• forming a metal silicide layer over the gate structure to continuously cover the first doped region and the spacing region, wherein the metal silicide layer is formed from the continuous disorder region.