Lawrence Livermore National Laboratory (LLNL)

Livermore National Laboratory (LLNL) will advance GaN device processing knowledge to enable production of GaN devices with higher speed and power at a lower cost. Using a selective area p-type doping process to move the device architecture from a lateral to a vertical configuration makes the lower cost possible. LLNL has previously demonstrated solid-state diffusion of magnesium (Mg) into GaN at temperatures under 1000ºC through a Gallidation Assisted Impurity Diffusion (GAID) process. In the GAID process, an Mg source layer is deposited in contact with the GaN followed by a capping layer of a metal that reacts with GaN at moderate temperatures to form gallides. The closeness of this capping layer with the GaN allows reaction with the underlying GaN, removing gallium from the lattice where it is replaced with Mg. This results in Mg incorporation within the GaN lattice and p-type doping. LLNL will evaluate various Mg sources, capping layers, and diffusion conditions for the GAID process and determine the relationship among source type, thickness, and capping layer on the resulting p-type doping concentration.

If successful, PNDIODES projects will enable further development of a new class of power converters suitable in a broad range of application areas including automotive, industrial, residential, transportation (rail & ship), aerospace, and utilities.