Schottky barriers on phosphorus-doped hydrogenated amorphous silicon: The effects of tunneling
- 15 May 1986
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 33 (10), 6936-6945
- https://doi.org/10.1103/physrevb.33.6936
Abstract
A systematic investigation of the transport properties of PtSi on phosphorus-doped hydrogenated amorphous silicon (a-Si:H) interfaces is presented. The transition from rectifying Schottky barriers to Ohmic contacts is observed as the doping level is increased. The barrier heights of PtSi on a-Si:H versus doping concentration and applied bias are measured with use of internal photoemission. In addition, the activation energy, ideality factor, flat-band voltage, and reverse-bias current-voltage characteristics are also determined. The results are analyzed in terms of the theory for thermionic-field-emission tunneling through the barrier. The agreement indicates that tunneling is extremely important for barriers on all but the lowest-doped a-Si:H at room temperature. While a change ∼0.6 eV of the effective barrier height is observed, the analysis indicates that the actual barrier height is independent of doping despite a change in the Fermi level of ∼0.4 eV. No evidence for the lowering of the barrier due to phosphorus-induced donor levels is found. The origin of the barrier formation and evolution of the electrical characteristics of the contact as a function of doping are discussed.Keywords
This publication has 17 references indexed in Scilit:
- Donor States in Hydrogenated Amorphous Silicon and GermaniumPhysical Review Letters, 1985
- Interface kinetics at metal contacts on a-Si:HJournal of Non-Crystalline Solids, 1983
- Measurements of depletion layers in hydrogenated amorphous siliconPhysical Review B, 1983
- Doping and the Fermi Energy in Amorphous SiliconPhysical Review Letters, 1982
- Direct measurement of gap-state absorption in hydrogenated amorphous silicon by photothermal deflection spectroscopyPhysical Review B, 1982
- Capacitance studies on amorphous silicon Schottky barrier diodesJournal of Non-Crystalline Solids, 1980
- The interpretation of capacitance and conductance measurements on metal-amorphous silicon barriersPhilosophical Magazine Part B, 1979
- Surface states and barrier heights of metal-amorphous silicon schottky barriersSolid State Communications, 1977
- Normalized thermionic-field (T-F) emission in metal-semiconductor (Schottky) barriersSolid-State Electronics, 1969
- Field and thermionic-field emission in Schottky barriersSolid-State Electronics, 1966