Investigation into the Characteristics of DC Nitrogen Plasma Used for Group III-N Semiconductor Thin-Film Growths

The active atomic nitrogen (N) species required for group III-N semiconductor material growth may be provided by a pure N-2 gas ignited through a hollow cathode DC plasma system. An advantage of using nitrogen plasma over other common nitrogen-containing compounds, such as ammonia, is the ability to efficiently produce N species at significantly lower temperatures. Through the analysis of collected spectroscopic and Langmuir probe data, the characteristics of a DC nitrogen plasma source were investigated at room temperature and at a N-2 flow rate of 500 sccm. The effects of varying plasma parameters on GaN thin-film growths on sapphire substrates were also investigated.