A Technique for Implanting Dopant Distributions in Solids

Abstract

In many material studies, a specific distribution in depth of a dopant is required. In this paper, a method of obtaining a wide variety of distributions in depth of implants is described. The depth, measured normal to the surface, of the implanted species can be varied by changing the angle between the surface normal and the incident beam direction. A given dopant distribution can be obtained by implanting for a predetermined time or accumulated charge at each of a large number of incident beam angles. Computer programs are reported which calculate the waiting times, plot the theoretical dopant distribution, and drive a stepping motor in such a manner as to provide the desired concentration of the dopant at each depth.