HGCDTE-MISFET FABRICATION WITH MULTISTEP SURFACE PASSIVATION AND QUANTUM EFFECTS

We have used multi-step surface passivation process integrating electr ochemical reduction and W exposure with native sulfidization by H2S ga s to obtain high quality ZnS/p-HgCdTe interface. It shows very low par asitic interface charge density of the order of 10(10)cm(-2). The insu lating ZnS layer also exhibits very high resistivity of similar to 10( 12) Ohm cm. The resulting fabricated HgCdTe-MISFETs show 2D quantum ef fects. magnetoresistance measured at 1.5K displays oscillations which begin to appear above the gate voltage of 10V. They are identified as the Shubnikov-de Haas oscillations involving three electronic subbands .The magnetotransport data are quantitatively analyzed with the calcul ated Landau level-fan diagram and confirm the 2D subband quantization of the inversion layer at the ZnS/p-HgCdTe interface. This result demo nstrates successful role of the multi-step surface passivation for rea lizing 2D ZnS/HgCdTe interface which will provide high quality 2DEG re sevoir basis in future Hg-based narrow-gap nanostructure device applic ations.