Field emission from GaAs pyramids fabricated using selected area vapor phase epitaxy

We report the fabrication of GaAs pyramids using selected area organometallic vapor phase epitaxy (SA-OMVPE) and field emission characteristics obtained from these structures. The use of crystal planes to define structure surfaces offers an attractive way of fabricating atomically sharp tip apexes in field emitter arrays (FEAs). For example, diamond crystals typically form such sharp apex structures. To use crystal structures as field emitters in a FEA, the orientation and size of the crystal surfaces must be controllable and consistent over the array, and the crystal should have electronic properties compatible with field emission. When high transconductance or high emission currents are required, these electronic properties should include a low resistance electron injecting contact, high bulk conductivity, and a modest surface potential barrier for electron field emission. In addition, formation of the tip structure must be compatible with formation of an adequate gate aperture. III-V semiconductor crystals grown by SA-OMVPE may provide a material and fabrication system capable of satisfying all these requirements.