The fabrication of semiconductor electronics and other micromanufactured devices is steadily evolving to smaller dimensions of the components and thus greater density of the microelements. As the dimensions of the components decrease to the one micrometer level and below, the problems of contamination during manufacturing become of increasing importance.
It has been recognized in the art that the fabrication of the devices must be carried out under rigid control of contaminants and particulates. Of special concern to the semiconductor industry which manufactures large scale integrated circuits is the control of the particulates during the process of implantation of electrically active ions into silicon wafers.
One implantation procedure now used during the processing of silicon wafers used for manufacturing semiconductor devices (including large scale integrated circuits) involves a number of steps, each of which may have a high potential for contaminating the wafer with particulates of the order of one micrometer. Among these steps are the transfer of the wafer into a vacuum chamber, spinning the wafer at high rotational speeds, bombarding the wafer with high currents of energetic ions, and removing the wafers from the chamber to a next processing stage. U.S. Pat. Nos. 4,234,797 to Ryding and 4,419,584 to Benveniste disclose prior art ion beam implantation systems particularly suited for doping semiconductor substrates and are expressly incorporated herein by reference. The present invention offers an automated way of keeping the level of particulates below the maximum allowed by the industry.