GaN Ohmic contact resistance vs temperature

The temperature impact on the Ohmic contact to Gallium Nitride (GaN) device properties is investigated in the range of 25°C to 300°C by means of the Transmission Line Method (TLM) technique. This study is centered in two kinds of Ohmic contacts: Implanted N
⁺
GaN and heterojunction AlGaN/GaN contacts. For N
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contact resistance behavior is explained in terms of the field-effect or thermionic field effect current transport mechanism. However, the heterojunction contact resistance behavior is explained by the mobility properties in the two dimensional electron gas.