We have used multi-step surface passivation process integrating electrochemical reduction and UV exposure with native sulfidization by H2S gas to obtain high quality ZnS/p-HgCdTe interface. It shows very low parasitic interface charge density of the order of 1010cm-2. The insulating ZnS layer also exhibits very high resistivity of ∼1012 Ωcm. The resulting fabricated HgCdTe-MISFETs show 2D quantum effects. 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 calculated Landau level-fan diagram and confirm the 2D subband quantization of the inversion layer at the ZnS/p-HgCdTe interface. This result demonstrates successful role of the multi-step surface passivation for realizing 2D ZnS/HgCdTe interface which will provide high quality 2DEG resevoir basis in future Hg-based narrow-gap nanostructure device applications.
Bibliographical noteFunding Information:
This work was supported by BSRI-97-2435 and Korea Agency for Defense Development.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry