Eliminating buried contact trench in mosfet devices having self-aligned silicide

Abstract

A MOSFET device with buried contact structure on a semiconductor substrate has the following major elements with their relative locations. A gate insulator is on a portion of the substrate and a gate electrode is on the gate insulator. A gate sidewall structure is located on sidewalls of the gate electrode. Inside the substrate, a lightly doped source/drain region is under the gate sidewall structure, and a doped source/drain region is abutting the lightly doped source/drain region and located aside from a region under the gate sidewall structure. In addition, a doped buried contact region is also in the substrate next to the doped source/drain region. On the substrate, a silicon connection is located on a portion of the doped buried contact region, and a shielding block is on the doped buried contact region covering only a region uncovered by the silicon connection. Specifically, the shielding block includes dielectric sidewalls and silicon sidewalls and the shielding block is formed right next to the edge of the silicon connection.