非极性GaN用r面蓝宝石衬底

R-plane Sapphire Substrate for Non-polar GaN Film

采用温梯法生长了非极性GaN外延衬底r(012)面蓝宝石,使用化学机械抛光加工衬底表面,对衬底的结晶质量、光学性能和加工质量进行了研究.结果显示r面蓝宝石衬底基本性能参数如下:平均半峰宽值为19.4arcsec;位错密度为5.6×103cm-2,波长大于300nm时的平均透过率大于80%;光学均匀性Δn=6.6×10-5;平均表面粗糙度为0.49nm.结果表明,温梯法生长的r(012)面蓝宝石衬底结晶质量好、位错密度低、光学性能优良、加工的表面质量高,达到了GaN外延衬底的标准.

R-plane sapphire used for epitaxial growth of non-polar GaN film was grown by the temperature gradient technique （TGT） method and chemical mechanical method was used to polish the r-plane sapphire substrate.The crystallization quality,optical property and surface roughness of as-obtained r-plane sapphire substrate were investigated.The average full width at half maximum （FWHM） of the substrate is 19.4arcsec and the dislocation density is 5.6×10^3cm^-2.The transmission of the substrate is higher than 80% when the wavelength is longer than 300nm and the optical homogeneity is 6.6×10^-5.The average surface roughness of the r-plane sapphire substrate is 0.49nm.The results indicate that as-obtained r-plane sapphire substrate meets the basic standard of GaN substrate.