Analysis of PdGe-based contact on n-GaSb

摘要

Pd-Ge based ohmic contacts on III-V semiconductor e.g. Pd-Ge on n-GaAs are viewed as a viable alternative to low contact resistance metallization. As it was remarked [1], together with the device dimensions decrease, the AuGeNi metallization system becomes inadequate for shallow-junction devices. This characteristic is related to the formation of a low melting point β-AuGa phase that leads to a poor contact thermal stability. Gallium Antimonide is anIII-V semiconductor compound that can be used in a photovoltaic convertor of GaAs/GaSb tandem stack with a predicted efficiency of 30%. Reduced series resistance on GaSb cells can be achieved by the improving of contact metallization properties. The present study is dedicated to the preparation conditions and structural analyzing of PdGe based contacts on n-GaSb, namely: Pd/Au/Ge. There are presented the depth profiling for PdGe metallization obtained from XPS measurements, and morphologic studies arisen from SEM technique and AFM technique.