Transmission Line Model (TLM) Method Study of Nanostructural AuGeNi/n-GaAs Ohmic Contact Layer for Different Substrate Deposition Temperature

Because of the importance of ohmic contact in semiconductor devices, in this study, AuGeNi thin films were depositedby thermal evaporation technique at substratedeposition temperaturefrom 80 °C to 230 °C andannealed at the same conditions. Thencontact resistivity and surface morphology was investigated. Surface morphology wasinvestigatedby Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The compositions of differentzones have been determined by use of x- ray Energy-Dispersive Spectrum (EDS) analysis. Contact resistivity of the samples ismeasured using a conventional Transmission Line model (TLM) method.So from the I-V curves and the other mentioned analysis results, it is concluded that the sample which was deposited at180°C indicates the best electrical and morphological properties.

Keywords:

Ohmic contact , substrate temperature , AuGeNi/n-GaAs , Transmission Line model (TLM