GaN Films deposited on ITO coated glass

Abstract

GaN films have been fabricated on tin doped indium oxide (ITO) coated glass substrates by electron cyclotron resonance plasma enhanced metal organic chemical vapour deposition. Trimethyl gallium (TMGa) and N₂ were acted as precursors of Ga and N respectively. A GaN buffer layer was introduced to reduce the internal stress between the substrate and the GaN films. Then, the deposition process was performed in N₂ rich atmosphere at a constant substrate temperature as low as 460°C. The TMGa flowrate was fixed at 1·5 sccm and N₂ flowrate varies from 80 to 110 sccm to investigate the influence of N₂ flux rates on the films’ properties. Reflection high energy electron diffraction and X-ray diffraction results indicate that all deposits are highly c axis oriented, whereas the characteristics of photoluminescence spectra are strongly affected by the N₂ flowrates. GaN films prepared at 100 sccm has a smooth surface and exhibits the optimal illumination performance. This inexpensive GaN/ITO/glass structure has potential application in optoelectronic devices.

Keywords:

• GaN films
• ITO substrates
• N₂ flux
• Low temperature deposition
• ECR-PEMOCVD