8英寸Si衬底上高质量AlGaN/GaN HEMT结构的生长

Growth of High Quality AlGaN/GaN HEMT Structures on 8-inch Si Substrates

在8英寸（1英寸=2.54 cm）的Si衬底上采用金属有机化学气相沉积（MOCVD）生长了高质量、无龟裂的GaN薄膜和Al GaN/GaN高电子迁移率晶体管（HEMT）结构。通过调节应力调控层的结构,厚度为5μm的GaN膜层翘曲度低于50μm。采用X射线衍射（XRD）对GaN薄膜的（002）和（102）衍射峰进行扫描,其半峰全宽（FWHM）分别为182和291 arcsec。透射电子显微镜（TEM）截面图显示GaN外延层的位错密度达到了3.5×107/cm^2,证实了在大尺寸Si衬底上可以制作高质量的GaN薄膜。Al GaN/GaN HEMT结构的二维电子气浓度和载流子迁移率分别为9.29×10^12/cm^2和2 230 cm^2/（V·s）。基于这些半绝缘Al GaN/GaN HEMT结构所制作的功率电子器件的输出电流可达20 A,横向击穿电压可达1 200 V。

High quality,crack-free GaN films and Al GaN/GaN high electron mobility transistor（ HEMT） structures were grown on 8-inch（ 1 inch = 2. 54 cm） Si substrates by metal organic chemical vapor deposition（ MOCVD）. The warpage of the GaN film with a thickness of 5 μm was lower than50 μm by adjusting the structure of the stress control layer. The（ 002） and（ 102） diffraction peaks of the GaN film were scanned by X-ray diffraction（ XRD）,showing that the full widths at half maximum（ FWHM） are 182 and 291 arcsec,respectively. Cross-sectional images of the transmission electron microscope（ TEM） show that the dislocation density of the GaN epitaxial layer is 3. 5×107/cm^2,confirming that the high quality GaN film can be produced on large size Si substrates. The two-dimensional electron gas concentration and carrier mobility of the Al GaN/GaN HEMT structure are 9. 29 × 1012/cm^2 and 2 230 cm^2/（ V·s）,respectively. The power electronics device produced based on the Al GaN/GaN HEMT structure shows a maximum output current of 20 A and lateral breakdown voltage of 1 200 V.