A new MOSFET structure with self-aligned polysilicon source and drain electrodes

A new MOSFET structure whose source and drain electrodes are self-aligned to the gate electrode is proposed. The new structure utilizes a second layer of polysilicon which is defined by a preferrential etching to form the source and drain regions. Due to the self-alignment property of the source and drain regions, the total device size is decreased by about 50 percent over the conventional MOS transistors when the same design rule is used. Experimental results of the new structure are presented.