Laser-assisted deposition technique for thin semiconductor layers and low-dimensional structures growth

Laser-assisted deposition technique (LAD) is analyzed as a method of obtaining high quality IV-VI and II-VI (HgCdTe) narrow-gap semiconductor thin layers and low-dimensional structures with abrupt metallurgical boundary and homogeneous impurity distribution in the layers. The basic structural, electrical, and electron paramagnetic resonance (EPR) of Mn2+ and Eu2+ in films and structures grown by LAD technique on different substrates at relatively low temperatures are analyzed. Using LAD technique with quasi-continuous regime of target evaporation by CO2 laser (101 <EQ f <EQ 103 Hz), where f is the modulation frequency of the laser beam in the transparency region of semiconductors used (hv < Eg) it was shown that the substrate temperature can be lowered to T approximately equals 300 K in the process of thin monocrystalline films and heterostructures growth. Several types of single crystal dielectric substrates with different lattice parameters ao were for LAD technique of Pb1-xSnxTe, PbSe and Hg1-xCdxTe layers and structures growth. It was shown that even in the case of large lattice mismatch (Delta) ao/ao approximately equals 30 percent there exist technological conditions for growth of monocrystalline semiconductor layers. In dependence of substrate temperatures and laser power densities used for semiconductor targets evaporation the growth rate of layers in a vacuum chamber with residual vapor pressure of 10-6 Torr was in the range of 102-103 angstrom/s.