EPITAXIAL GROWTH METHOD OF COMPOUND CRYSTAL

摘要

PURPOSE:To improve intra-surface uniformity by irradiating a crystal grown film with light and measuring the intensity of the reflected light thereof at the time of crystal growth, then adjusting the amt. of the gaseous raw materials to be introduced according to the change of the reflected light intensity and controlling the growth of the grown film. CONSTITUTION:Gas control valves 8a, 8b are controlled by a control system to alternately introduce several kinds of raw materials and gaseous raw materials onto a compd. single crystal substrate 10 heated by a lamp 7 to epitaxially grow the compd. crystal. An He-Ne laser beam or the like of a light source 1 is chopped by a chopper 2 and the compd. single crystal is irradiated with the chopped beams through a incident window 6a. The reflected light is taken out and is detected through a window 6 by a photodetector 4, such as Si photodiode. The detected output is subjected to signal processing by a lock-in amplifier 3 and is outputted to a display 15 and a decoder 16 of a control system. A change in the intensity of the reflected light is measured from the correlative relation between the thickness of the grown film and the intensity of the reflected light and the amt. of the gaseous raw materials to be introduced is adjusted. The desired grown film is thus obtd. with the accuracy of a monomolecular layer or below.