What the process engineer really wants is to have 95% of the Boron just below the oxide. However there is an oxide thickness and tolerance of 110nm +- 4nm. Also, there is an implanter voltage reduction of up to 8% from the nominal voltage because the implanter high voltage source gradually reduces voltage until the machine power supply is serviced annually. (This is a low cost factory using a budget implanter).So what is the minimal implanter energy that you need to implant the Boron under these conditions to guarantee that 95% of the Boron is below the oxide (SiO2). What is the straggle?