Chartered Semiconductor Manufacturing Ltd (corporation)

Globalfoundries Singapore Pte. Ltd.

Kian Meng Tee

Yisuo Li

Francis Benistant

King Jien Chui

Kheng Chok Tee

Ganesh S Samudra

Kum Woh Vincent Leong

A structure and method of reducing junction capacitance of a source/drain region in a transistor. A gate structure is formed over on a first conductive type substrate. We perform a doped depletion region implantation by implanting ions being the second conductive type to the substrate using the gate structure as a mask, to form a doped depletion region beneath and separated from the source/drain regions. The doped depletion regions have an impurity concentration and thickness so that the doped depletion regions are depleted due to a built-in potential creatable between the doped depletion regions and the substrate. The doped depletion region and substrate form depletion regions between the source/drain regions and the doped depletion region. We perform a S/D implant by implanting ions having a second conductivity type into the substrate to form S/D regions. The doped depletion region and depletion regions reduce the capacitance between the source/drain regions and the substrate.

Structure and method to form source and drain regions over doped depletion regions

A method for forming elevated source/drain regions. A gate structure is formed over a substrate. The substrate comprised of silicon. We form a polysilicon layer preferably using PVD or CVD over the gate structure and the substrate. A poly/Si interface is formed between the polysilicon layer and the substrate. We perform a poly/Si interface amorphization implant to amorphize at least the poly/Si interface in the S/D areas and to from an amorphous region. We anneal the substrate to crystallize the amorphous region and the polysilicon layer over the amorphous region to form an elevated silicon region in the source/drain area. Next, source/drain regions in are formed in the elevated silicon regions and the substrate.

Low cost source drain elevation through poly amorphizing implant technology

Growing community of inventors

Singapore, Singapore

Kian Meng Tee