Using transfer matrix to analyze the dosimetry of ion implanters

Parallelism and uniformity are the two basic requirements of the modern medium current ion implanters. These two are usually called dosimetry. We have developed, for the first time, an analytical tool for the dosimetry study. Borrowed from a concept in accelerator physics, the transfer matrix has been used for these studies. Because of the large non-linearity in the fields of the devices, the standard method of the transfer matrix has been modified for our purpose. Some simplifications are also necessary. This paper applies this new method to the Eaton NV-8250 ion implanter. The analytical results show that it not only helps us to understand the correlation between dosimetry and hardware, but also provides a scaling law to guide the future performance improvement. We believe that this analytical tool can be applied to other implanters