Microhardness of 6H-SiC Epitaxial Layers Grown by Sublimation

Knoop microhardness of 6H-SiC layers grown by sublimation epitaxy was investigated. The microhardness-load curves for all of the samples were measured and then used to extract the load-independent microhardness values. The relationships of these values to the growth time and growth rate were studied. The microhardness-depth profiles indicated that the layer/substrate interface region had a microhardness value that differed significantly from that of both the epi-layer and the substrate.     

On the scandium distribution in indium arsenide crystals grown by the Czochralski method

In this paper the behaviour of scandium in n-type monocrystalline indium arsenide grown by Czochralski method in sealed ampoule is studied. The crystals have been grown in [111] direction under different conditions: crystallization rate, As-partial pressure and scandium initial concentration in the melt. The effect of the above factors on the scandium distribution along the crystals have been investigated. Using these results and by means of the equation of normal freezing the effective Sc distribution coefficient (k) in InAs under different technological conditions has been determined. It has been found that k < 1 in all experiments. In order to find the equilibrium coefficient (k₀) at fixed growth conditions the Burton-Prim-Slichter model has been used. On the basis of Hall measurements and atomic absorption analysis of Sc-doped InAs it is concluded that connected with Sc electrically active centers behave as shallow donors, most probably monovalent ones.