Schottky contacts
Schottky contacts are one of the most widely studied aspects of GaAs technology. In part, this is due to the fact that no single Schottky contact satisfies all of the requirements for an ideal Schottky contact to GaAs. Another factor driving more research has been the desire for higher Schottky barrier heights. Yet another factor has been the poorly understood nature and reproducibility of the metal/GaAs interface. In spite of the existence of contacts with greater interface stability, TiPtAu exhibits more than sufficient reliability against gate sinking in GaAs-based FETs. However, TiPtAu should be used with hydrogen getters for hermetic packages or be replaced with non-Ti and non-Pt materials. Many choices of refractory contacts can be used for high-temperature self-aligned FETs. Some of the best are WSi0.45 and WSiN because these remain amorphous to sufficiently high temperatures. A wide variety of processing choices are available to tailor the gate structure to the desired application using available equipment.
Schottky contacts, Page 1 of 2
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