TECHNIQUES FOR REDUCING THE REVERSE SHORT-CHANNEL EFFECT IN SUB-0.5 MU-M CMOS

Experimental evidence is presented demonstrating that the reverse shor t channel effect (RSCE) is initiated by damage from the source-drain i mplants which, in turn, causes defect-enhanced diffusion of the channe l dopants toward the gate oxide interface. Several process options tha t attempt to modify the diffusion of the channel implants, such as cha nnel doping profile engineering, vacancy injection into the silicon su bstrate through sputter-etch damage, and TEOS depositions on silicon f ollowed by rapid thermal annealing, are described which reduce the mag nitude of the reverse short channel effect. This often results in an i ncrease in device short channel margin of as much as 50 nm and a conco mitant increase in the n-channel drive current of as much as 10%.