A method of fabricating a large number of cube-shaped monocrystal pieces with sides on the order of 1 to 3 mm is known in the prior art as a method of fabricating pieces of a semiconductor crystal, such as a monocrystal or multicrystal semiconductor of a bismuth/tellurium compound; which involves slicing an ingot of monocrystal or multicrystal grown in an a-axial direction by a downward-drawing method to form circular plates, then dicing these circular plates.
Other methods, such as Edge-defined Film-fed Growth (EFG) and crosscut methods, are also known in the prior art as methods of fabricating sheets of semiconductor crystal such as silicon ribbon crystals.
However, the above method of fabricating monocrystal or multicrystal semiconductor pieces of a bismuth/tellurium compound necessitates a cutting process of one slicing step and two dicing steps, so it is expensive.
Furthermore, the silicon melt solidifies at a speed of ten to several hundred mm/minute with the above EFG and crosscut methods, so the grain size of the completed crystals is small and thermal stresses still remain therein, and thus quality is poor.
The present invention was devised in the light of the above problems and has as an objective thereof the provision of an inexpensive method of fabricating shaped crystals of a needle shape (diameter: approximately 0.5 mm to 3 mm) or sheet shape (thickness: approximately 0.5 mm) from a high-quality bismuth/tellurium compound or other semiconductor.
USPTO Backgrounds
USPTO Backgrounds