Improved dose uniformity by utilizing the beam profile in the ion implantation process

The speed of adjusting the spinning disk at high current implanters depends on both the position of the centre of the beam limiting aperture with respect to the centre of the disk and the intensity distribution of the beam. Taking into consideration the intensity distribution of the beam, a proper reference point can be defined. Thus the dose uniformity will be improved by at least 0.1%. Since in many cases the maximum value of the acceptable dose non-uniformity is of the order of 0.5%, the method proposed may lead to a reduction of 10-20% of the dose non-uniformity. (orig.)