NOVEL SUBMICRON LDD TRANSISTOR WITH INVERSE-T GATE STRUCTURE.

A novel submicrometer lightly doped drain (LDD) transistor with an inverse-T (IT) gate structure has been demonstrated. The structure provides self-alignments of n- LDD and n** plus source-drain implants to IT gate structure. The self-aligned n** plus -to-gate feature allows for a lower n- LDD dose and minimum postimplant drive-in on the optimized transistor. Improved transconductance and extrapolated lifetime of more than 10 years have been achieved for 0. 6- mu m ITLDD NMOS transistors. The ITLDD offers an excellent possible device structure for future CMOS processes in which minimum thermal processing is necessary for p-channel transistors.