Properties of ZrN films as substrate masks in liquid phase epitaxial lateral overgrowth of compound semiconductors

Abstract

The usefulness of ZrN films as masks for epitaxial lateral overgrowth of GaAs and GaSb by liquid phase epitaxy is studied. It was observed that during the growth process ZrN masks are mechanically stable, they adhere strongly to the substrate and do not show any signs of degradation even at the growth temperature as high as 750°C. Moreover, perfect selectivity of GaAs and GaSb epitaxy was obtained on ZrN masked substrates ensuring the growth wide and thin layers. To study the influence of growth conditions on electrical resistivity of the mask, ZrN films deposited on GaAs substrates were annealed in various atmospheres. It was found that at temperatures higher than about 580°C the ZrN masks become highly resistive when heat-treated in hydrogen flow employed during growth. Usually, LPE growth temperature for GaAs is higher. Thus, ELO growth of GaAs by LPE becomes more difficult, though still possible, if ZrN masks are to be applied as buried electrical contacts. For GaSb ELO layers however, typical LPE growth temperature is about 480°C. This allows us to grow high quality GaSb ELO layers by LPE still preserving high electrical conductivity of ZrN mask.

Nanostructured multilayers of TiN/ZrN obtained by magnetron sputtering

“…We observed a homogenous surface morphology with low porosities as expected for the sputtering bias parameter used for the growth of this sample [13,15]. The bias voltage used was -100 V. It has been observed that these porosities are present on the film surface only when the negative bias voltage is applied.…”

Hard coating performance enhancement by using [Ti/TiN]n, [Zr/ZrN]n and [TiN/ZrN]n multilayer system

“…The 4 bilayers are clearly distinguished from the SIMS spectra due to modulation of nitrogen signal ( 14 N + ), confirming the number of bilayers (4). The increase and the reduction of the nitrogen content in the gas flow is clearly seen [15,19] indicating a partial conversion of metallic ( 83 Zr + signal) in the compound of Zr-N caused by flow of nitrogen, forming thus multilayers films responsible of high mechanical properties [20,21]. SIMS profile for [TiN/ZrN] 4 multilayer is present in Fig.…”

Liquid-Phase Epitaxy

“…Hayashi et al [396] made virtual substrates of lattice-mismatched In 0.8 Ga 0.2 P on oxide-masked (111) GaAs using epitaxial lateral overgrowth LPE. Dobosz et al [400] reported the use of ZrN as a mask for LPE ELO. The aspect ratio is defined as the lateral width of the selectively grown crystal to the thickness of the crystal.…”