| AVS 54th International Symposium | |
| Plasma Science and Technology | Monday Sessions |
| Session PS-MoA |
| Session: | Plasma Processing for High k, III-V and Smart Materials |
| Presenter: | S.J. Pearton, University of Florida |
| Authors: | S.J. Pearton, University of Florida L.F. Voss, University of Florida W.T. Lim, University of Florida R.J. Shul, Sandia National Laboratories |
| Correspondent: | Click to Email |
A review will be given of dry etching of three technologically important wide bandgap semiconductors, namely GaN,SiC and ZnO. Dry etching of GaN is needed for mesa formation on electronic and photonic devices and for through-wafer vias on power devices. Generally chlorine-based plasma chemistries are used, with etch rates in the range of a few thousand angstroms per minute to almost one micron per minute. A typical issue is the preferential loss of nitrogen from the near-surface region, leading to the presence of an n-type surface layer after etching. This can be used to advantage in improving contact resistance of n-type Ohmic contacts. For SiC, the main chemistries are based on fluorine and changes to the surface electrical properties are less of an issue. For ZnO, the low volatility of all Zn etch products leads to low etch rates at room temperature and changing to iodine or bromine chemistries does not improve the removal rates. Examples will be given of device etching processes for all three materials systems.