USINQ FIELD OXIDATION HEAT CYCLE TO DRIVE IN PUNCH THRU IMPLANT
Original Publication Date: 1984-Apr-01
Included in the Prior Art Database: 2001-Oct-12
In conventional MOS device processing, threshold adjustment doping is selectively implanted into the active.device region using thick field oxide as a masking layer. In order to improve punch thru voltage on short channel devices, deep implants were performed either by high voltage or doubly ionized species techniques. If a higher voltage implant is used, more expensive equipment is required. If doubly ionized species is used, the current supplied by the implanier is reduced, slowing processing time. The vertical structure for this kind of conventional processing can be illustrated in Figure 1.