A process control method is provided for ion implantation methods and apparatuses, to produce a high dosage area on a substrate such as may compensate for noted non-uniformities. The difference between the maximum value of leading-edge skew and the value of leading-edge skew at the fan radius is at least 10 degrees. 80 bar and high temperatures of e. This b value or fitting constant corresponds to the intersection of the y-intercept and the best fit line. Methods for providing the compositions are disclosed.