Method of fabrication of a semiconductor device having high-and low- voltage MOS transistors

摘要

A semiconductor device (76) is provided with a high-voltage portion including NMOS transistor (78) and PMOS transistor (82b) and a low- voltage portion including NMOS transistor (80) and PMOS transistor 82(a). The high-voltage NMOS transistor (78) includes source/drain regions (90a, 90b) having N- regions (90a.sub.1, 90b.sub.1) that are self- aligned with a gate (78) and N+ regions (90a.sub.2, 90b.sub.2) that are self-aligned with sidewall spacers (91) formed on sidewalls of the gate (78) to improve reliability under continuous high voltage operating conditions. The low voltage NMOS transistor includes source/drain regions (92a, 92b) that are self-aligned with sidewall spacers (92) to permit channel lengths to be scaled to less than 2 microns. The low-voltage PMOS transistor (82a) and high-voltage PMOS transistor (82b) include source/drain regions (116a-16d) that are self-aligned with sidewall spacer extension regions (110a) formed over sidewall spacers (91) permitting low-voltage PMOS transistor channel lengths to be scaled to less than 2 microns.