Development of Epitaxial GaN Films for RF Communications, Phase I

The primary objective of this SBIR is to develop epitaxial GaN films with threading dislocation density less than 10^6 cm^-2. We propose an innovative approach combining two Pulsed Energy technologies: plasma-energy-controlled Pulsed Laser Deposition (PLD) to deposit high quality epitaxial GaN films, and in situ Pulsed Energy Annealing to decrease the dislocation density ( to < 10^6 cm-2). Unlike low energetic techniques (such as MBE or CVD), PLD's energetic range of pulsed plasma can be controlled with process parameters, resulting in a wide range of plasma energetic for film deposition. Recently, Neocera fabricated high quality epitaxial GaN films using the plasma-energy-controlled PLD process, resulting in strong photoluminescent emission at room temperature. This approach is further extended in this Phase I, with an in-situ "Pulsed" Energy Annealing, to greatly improve the film crystallinity. The pulsed laser or pulsed electron beam, with 20-50 ns pulse width and high power density (~10^8W/cm^2), induces melting and a rapid epitaxial formation in ~100 nanoseconds, anneling out dislocations. This unique combination of two pulsed energy technologies is expected to provide the most advanced deposition process for epitaxial GaN films with low dislocation density. More »