초록 ▼

A method of forming a retarded double diffused drain structure, and the resultant retarded double diffused drain structure, for a field effect transistor are described. A silicon substrate with field isolation regions and a gate structure is provided. A layer of photoresist is formed on the field is

A method of forming a retarded double diffused drain structure, and the resultant retarded double diffused drain structure, for a field effect transistor are described. A silicon substrate with field isolation regions and a gate structure is provided. A layer of photoresist is formed on the field isolation region, the silicon substrate, and the gate structure. The photoresist is patterned to expose the silicon substrate and the gate structure, but covers an area of the silicon substrate that is offset from the field isolation regions. A first ion implant is performed in a vertical direction in exposed regions of the silicon substrate, with suitable dopant having a high doping concentration. The photoresist is removed. A second ion implant is performed in a vertical direction in the silicon substrate, with suitable dopant with higher doping concentration than the first ion implant, in regions between the field isolation regions and the gate structure. The substrate is heated to drive in both the dopants.

대표청구항 ▼

A method of forming a retarded double diffused drain structure, in a silicon substrate with field isolation regions and a gate structure, comprising the steps of: first forming a layer of photoresist on the field isolation regions, the silicon substrate, and the gate structure; then patterning said

A method of forming a retarded double diffused drain structure, in a silicon substrate with field isolation regions and a gate structure, comprising the steps of: first forming a layer of photoresist on the field isolation regions, the silicon substrate, and the gate structure; then patterning said photoresist to expose the silicon substrate and the gate structure, but covering an area of the silicon substrate that is offset from the field isolation regions; then performing a first ion implant of a conductivity-modifying dopant in a vertical direction in exposed regions of the silicon substrate; then removing said photoresist; then performing a second ion implant of a conductivity-modifying dopant having the same conductivity type as in said first ion implant, in a vertical direction in the silicon substrate, wherein said second ion implant is at a higher Implantation dose than said first ion implant, in regions, between the field isolation regions and the gate structure; and heating the substrate to drive in dopants, whereby the outer edge, with respect to said gate structure, of a doped region formed by said first ion implant is offset from the outer edge of a more heavily doped region formed by said second ion implant.