MOCVD生长高Al组分AlGaN材料研究

报道了用MOCVD在蓝宝石衬底上生长日盲型AlGaN基紫外探测器用的高质量AlN、AlGaN材料。通过优化AlN、AlGaN生长的工艺条件,如生长温度、生长压力及Ⅴ/Ⅲ比等,得到了器件级高质量的AlN、AlGaN外延材料。AlN外延膜X射线双晶衍射ω(002)面扫描曲线半高宽为97",ω(102)面扫描曲线半高宽为870",Al0.6Ga0.4N外延膜双晶衍射ω(002)面扫描曲线半高宽为240";使用原子力显微镜(AFM)对两种样品5μm×5μm区域的表面平整度进行了表征,AlN外延膜的粗糙度(Rms)为8.484nm,Al0.6Ga0.4N外延膜的粗糙度为1.104nm;透射光谱测试显示AlN和Al0.6Ga0.4N吸收带边分别为205nm和266nm,且都非常陡峭。

Study of AlGaN Materials with High Al Fraction Grown By MOCVD

The high performance AlN and AlGaN materials for solar-blind AlGaN-based photo-detectors grown by metal-organic chemical vapor deposition(MOCVD)on c-plane sapphire substrates were reported.By optimizing the process parameters such as the temperature,Ⅴ/Ⅲ ratio and pressure,the high quality AlN and AlGaN materials were obtained.The results show that the full width at half maximum(FWHM)of AlN(002)ω-rocking curve in the double-crystal X-ray diffraction is 97",the FWHM of AlN(102)ω-rocking curve is 870",and the FWHM of Al0.6Ga0.4N(002)ω-rocking curve is 240".The surface roughness of 5 μm×5 μm area of each sample was characterized by atomic force microscopy(AFM).The Rms of AlN surface is 8.484 nm,and the Rms of Al0.6Ga0.4N surface is 1.104 nm。The transmission spectra of the samples were measured.The absorption bandedges of AlN and Al0.6Ga0.4N are very sharp,and are 205 nm and 266 nm,respectively.