SILICON HALIDES ARE FORMED IN A CONTINUOUS PROCESS BY REACTING SILICON OR A SILICON-CONTAINING COMPOUND WITH HYDROGEN HALIDE AT A TEMPERATURE BETWEEN 350 AND 1200*C. THE SILICON HALIDE IS THEN RECOVERED AND THE HYDROGEN FORMED IN THE REACTION IS RECYCLED IN AN AMOUNT TO PROVIDE A RATIO OF PARTIAL PRESSURES IN THE RE-

ACTION MIXTURE BETWEEN HYDROGEN HALIDE AND HYDROGEN IN THE RANGE BETWEEN 1:1 AND 1:50 AT A PREDETERMINED REACTION TEMPERATURE WITHIN THE STATED RANGE.