AN APPARATUS FOR PRECISION LOW TEMPERATURE VAPOUR DEPOSITION OF THIN FILM COATINGS ON WAFER SUBSTRATES

摘要

An apparatus for precision low temperature vapour deposition of thin film (1) coatings on water (2) substrates comprising a hot plate (14) the centre portion of which is raised and having means for holding the water in position and provided with a constant temperature heater and means for temperature measurement, a hollow cylinder open at both ends placed over the hot plate, the cylinder having outlet for the gases to escape and having a protruding outer ring at its top, a double walled reactor chamber (3) the bottom of which is open and closed at the top and having an inlet (8) for passing the gas mixture (17) the outer wall of the chamber provided with inlet (5) and outlet (6) means for passing water for cooling the chamber, the chamber also provided with a protruding ring (10) near about its middle and the chamber is removably placed over the cylinder in such a way that the protruding ring rests on the protruding rim (13) of the cylinder (11) and that the bottom ends of the chamber extends beyond the level of the raised portion (15) of the hot plate and forming a gap (19) between the upper surface of the hot plate and the bottom ends of the chamber for escape of the spent gases.