Investigation of the influence of graded-gap layer formed by annealing on the electrical properties of the near-surface of LPE HgCdTe using MIS structure
Open Access
- 1 January 2021
- journal article
- research article
- Published by IOP Publishing in Materials Research Express
- Vol. 8 (1), 015903
- https://doi.org/10.1088/2053-1591/abda6b
Abstract
The influence of the near-surface graded-gap layer formed by annealing of HgCdTe grown by liquid phase epitaxy on the capacitance-voltage characteristics of its MIS structure was studied. We found that HgCdTe grown by LPE can form a near-surface graded-gap layer by annealing under specific conditions after CdTe passivation. After the near-surface graded-layer is generated, the performance of the HgCdTe surface layer has been changed significantly, showing as an increase of slow states, a decrease of fixed charge and the generation of single-level trap in the band gap. Furthermore, a Fermi level pinning phenomenon have been observed on the HgCdTe with graded-gap layer, highlighting the huge density of interface traps at the edge of the band. This effect may be attributed to the electric field generated by the graded-gap layer in HgCdTe driving minority carriers away from the interface. As a result, the surface recombination velocity of minority carriers is reduced. At the same time, it inhibits the oxidation reaction on the surface and consequently reduces the accumulation of fixed charges. During the annealing process to form the graded-layer, the defect system on the surface is reorganized, and the defect aggregation produces single-level defects and higher electron traps.Keywords
This publication has 24 references indexed in Scilit:
- Capacitance–voltage characteristics of metal–insulator–semiconductor structures based on graded-gap HgCdTe with various insulatorsThin Solid Films, 2012
- Effect of Cycle Annealing Parameters on Dislocation Density Reduction for HgCdTe on SiJournal of Electronic Materials, 2011
- Studies on surface processing and passivation of p-Hg1−xCdxTeSemiconductor Science and Technology, 2007
- A CdTe passivation process for long wavelength infrared HgCdTe photo-detectorsJournal of Electronic Materials, 2005
- HgCdTe infrared detector material: history, status and outlookReports on Progress in Physics, 2005
- The Influence of Resistance of the Epitaxial-Film Volume on the Capacity-Voltage Characteristics of the HgCdTe/AOF and HgCdTe/SiO2/Si3N4 MIS StructuresRussian Physics Journal, 2005
- Dark currents in long wavelength infrared HgCdTe gated photodiodesJournal of Electronic Materials, 2004
- Passivation of HgCdTe p-n diode junction by compositionally graded HgCdTe formed by annealing in a Cd/Hg atmosphereJournal of Electronic Materials, 2002
- Effect of fixed charges due to a passivant on the performance of the HgCdTe overlap structureSemiconductor Science and Technology, 2002
- Molecular-beam epitaxy of mercury-cadmium-telluride solid solutions on alternative substratesSemiconductors, 2001