Anti-halo compensation

An apparatus and method for controlling the net doping in the active region of a semiconductor device in accordance with a gate length is provided. A compensating dopant is chosen to be a type of dopant which will electrically neutralize dopant of the opposite type in the substrate. By implanting the compensating dopant at relatively high angle and high energy, the compensating dopant will pass into and through the gate region for short channels and have little or no impact on the total dopant concentration within the gate region. Where the channel is of a longer length, the high implant angle and the high implant energy cause the compensating dopant to lodge within the channel thereby neutralizing a portion of the dopant of the opposite type.