Low-cost device relevant Indium Gallium Nitride (InGaN) or Alternatives

The project aims to grow device-quality InxGa1-xN, an important semiconductor because the band gap can be shifted widely by varying x, using a new form of plasma sputtering, Biased-Target Deposition (BTD). The major objectives are to grow x > 0.05 material on sapphire at 600-800°C (standard) and 300-500°C (beneficially reduced) temperatures, and to characterize material quality via X-ray diffraction and photoluminescence seeking defined criteria. BTD uses a separate plasma source to provide ions for sputtering, so low bias voltages on the targets produce unprecedented (for sputtering) low and controllable kinetic energies of arriving In, Ga and N atoms at the growing InGaN surface. The hypothesis will be tested that slightly elevated particle energies might replace the atom mobility effects of heating and allow growth at lower temperature, which would solve a well-known phase segregation problem in InxGa1-xN as x is increased. Techniques within BTD give an aggressive nitriding environment, starting from inert N2, so InGaN is grown by co-sputtering from separate In and Ga metal sputter targets, the Ga target being a molten pool.