摘要
文章基于蓝宝石衬底采用脉冲金属有机物化学气相淀积(MOCVD)法生长的高迁移率InAlN/GaN材料,其霍尔迁移率在室温和77K下分别达到949和2032cm2/Vs,材料中形成了二维电子气(2DEG).进一步引入1.2nm的AlN界面插入层形成InAlN/AlN/GaN结构,则霍尔迁移率在室温和77K下分别上升到1437和5308cm2/Vs.分析样品的X射线衍射、原子力显微镜测试结果以及脉冲MOCVD生长方法的特点,发现InAlN/GaN材料的结晶质量较高,与GaN晶格匹配的InAlN材料具有平滑的表面和界面.InAlN/GaN和InAlN/AlN/GaN材料形成高迁移率特性的主要原因归结为形成了密度相对较低(1.6×1013—1.8×1013cm-2)的2DEG,高质量的InAlN晶体降低了组分不均匀分布引起的合金无序散射,以及2DEG所在界面的粗糙度较小,削弱了界面粗糙度散射.
InAlN can be in-plane lattice matched (LM) to GaN,and the formed InAlN/GaN heterostructure is one kind of materials with high conductivity to be used in GaN-based high electron mobility transistors (HEMTs).It is reported that the high-mobility InAlN/GaN material is grown by using pulsed metal organic chemical vapor deposition (PMOCVD) on sapphire,and the Hall electron mobility reaches 949 and 2032 cm2/Vs at room temperature and 77 K,respectively.The two-dimensional electron gas (2DEG) is formed in the sample.When 1.2 nm thick AlN space layer is inserted to form InAlN/AlN/GaN structure,the Hall electron mobility increases to 1437 and 5308 cm2/Vs at room temperature and 77 K,respectively.It is shown by analyzing the results of X-ray diffraction and atomic force microscopy and the features of PMOCVD that the crystal quality of InAlN/GaN material is quite high,and the InAlN layer LM to GaN has smooth surface and interface.The high mobility characteristics of InAlN/GaN and InAlN/AlN/GaN materials are ascribed to the fact that the 2DEG has a comparatively low sheet density (1.6×1013—1.8×1013 cm-2),the alloy disorder scattering is weakened in the high-quality InAlN crystal since its compositions are evenly distributed,and the interface roughness scattering is alleviated at the smooth interface where the 2DEG is located.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第11期603-608,共6页
Acta Physica Sinica
基金
国家重大科学研究计划(批准号:2008ZX01002-002)
国家自然科学基金重大项目(批准号:60890191)、国家自然科学基金重点项目(批准号:60736033)
高等学校博士学科点新教师基金项目(批准号:200807011012)资助的课题~~