PULLING METHOD OF GAAS SINGLE CRYSTAL

摘要

PURPOSE:To dispense with formation of a flanging part of complicated shape, and to grow easily the titled single crystal by specifying the size of the seed crystal to be used in the method for pulling a GaAs single crystal with the liquid-capsule Czochralski method. CONSTITUTION:The material melt 1 is charged into a crucible which is heated with a heater, and the surface is covered with a B2O3 melt 2. A seed crystal 9 fixed at the lower end of a pulling shaft 7 is immersed into the surface of the melt 1. And a single crystal is pulled up while rotating the seed crystal 9. The size of the cross section of the seed crystal 9 is regulated so that the diameter of the seed crystal may be equal to the outer diameter of the single crystal or close to the outer diameter (>50% of the outer diameter). The shape of the cross section of the seed crystal 9 is not limited to circular form, and other shapes such as a square of a polygon can also be used. Namely, any shape having cross- sectional area close to that of the single crystal can be used.