A versatile target chamber in an ion implanter for metallurgical research

In an ion implanter for metallurgical research the target chamber must be easily adaptable for use with various samples and must also permit implantation under controlled conditions. The complexity of the samples movements and the length of the implantation process requires the automatic control of the chamber. This paper describes a target chamber designed to match these requirements. The sample holder is driven by three step-motors operated by a microprocessor control system. Depending on the sample and the desired implantation geometry, interchangeable supports may be used. The rotations are transmitted to them by stepping motors and these can be used independently or combined in order to produce the required movements. The control system is made up of an independent stepping motor driver interface and a microcomputer assembled with standard PCBs for industrial control. The microprocessor is a Z-80 model. The system software is based on FORTH, a high level structured language that permits flexibility and simplicity in the programming and use of the system. (orig.)