Investigation of crystallographic properties of thin germanium crystals grown on silicon substrates by chemical vapor deposition

The quality of germanium crystals deposited from the gas phase by chemical vapor deposition using pyrolytic decomposition of GeH₄ in a helium atmosphere at various growth temperatures on silicon substrates was determined. X-ray diffraction and rocking curve measurements proved to be very useful in determining the degree of preferred orientation of the germanium deposit, since they distinguish clearly between the reflections of the thin germanium deposited layer and those of the thick silicon substrate. Therefore they permit fairly accurate calculations. Laue measurements, in this case, proved to be unsatisfactory because of inadequately low resolution. The results show that a preferred orientation of germanium crystallites in the layer of up to 99.9% was reached.