A 7 mask CMOS-technology utilizing liquid phase selective oxide deposition

The authors describe a fully symmetric 7 mask CMOS technology, utilizing a room-temperature liquid phase oxide deposition technique which has selectivity against photo resist. They have developed process modules for self-aligned well and one mask LDD (lightly doped drain) formation which achieve excellent device performance. The main features of this CMOS technology are (1) very short processing time: (7 masks to first metallization); (2) self-aligned twin retrograde wells with 40% reduction of p/sup +/-n/sup +/ spacing; and (3) optimal LDD design using different-width side-wall spacers for n- and p-channel MOSFETs with a 10% larger on current for p-channel MOSFETs.<>