GB1348528A - Methods of and apparatus for growing crystals from solutions - Google Patents

Abstract

1348528 Crystallizing from a liquid WESTERN ELECTRIC CO Inc 25 May 1971 [27 May 1970] 16989/71 Headings BIG and B1S A solution is impelled by centrifuged force into contact with a substrate to grow a crystalline layer thereon epitaxially or otherwise. As shown, a solution 30, for example, of GaP or Ga As in Ga, which may be doped with oxygen and zinc, is heated by RF heaters 45 or 46. At the appropriate temperature, vessel 40 is spun about its axes 43, so that the liquid rises to immerse substrates 22, leaving the impurities behind. The position of the liquid surface during crystal growth is shown at 55. Impurities which either float 56A or sink 56B may be further separated by using an inner container 70, Fig. 6F, from which the melt escapes through holes 73 to immerse the substrates 22. The substrates may be free to move in the radial direction 62 (Fig. 4). Thus, a substrate which is denser than the solution will seat against surface 52 and be heated by heater 46 so that the growth face faces the direction in which the temperature gradient increases. A substrate which is less dense than the solution will seat against surface 60 and be heated by a heater 45. When crystal growth has been completed, the rotation is halted, and the solution falls and may drain into a well (67) or to a cup (90, Fig. 6C) surrounding vessel 40. Instead of spinning vessel 40, the solution may be rotated by an impeller immersed therein.