Large-scale GaN free-standing substrate was obtained by hydride vapor phase epitaxy directly on sapphire with porous network interlayer. The bottom surface N-face and top surface Ga-face showed great difference in anti-etching and optical properties. The variation of optical and structure characteristics were also microscopically identified using spatially resolved cathodoluminescence and micro-Raman spectroscopy in cross-section of the GaN substrate. Three different regions were separated according to luminescent intensity along the film growth orientation. Some tapered inversion domains with high free carrier concentration of 5 × 1019 cm−3 protruded up to the surface forming the hexagonal pits. The dark region of upper layer showed good crystalline quality with narrow donor bound exciton peak and low free carrier concentration. Unlike the exponential dependence of the strain distribution, the free-standing GaN substrate revealed a gradual increase of the strain mainly within the near N-polar side region with a thickness of about 50 μm, then almost kept constant to the top surface.
Source: Applied Surface Science
If you need more information about Characterization of free-standing GaN substrate grown through hydride vapor phase epitaxy with a TiN interlayer, please visit:http://www.qualitymaterial.net or send us email at email@example.com.
This is excellent information which is shared by you. This information is meaningful and magnificent for us to increase our knowledge about it. Keep sharing this kind of information. Thank you. Vapor Intrusion solutionsReplyDelete