Identification and elimination of inductively coupled plasma-induced defects in AlxGa1 - xN/GaN heterostructures

By using temperature-dependent Hall,variable-frequency capacitance-voltage and cathodoluminescence (CL) measurements,the identification of inductively coupled plasma (ICP)-induced defect states around the Al x Ga 1-x N/GaN heterointerface and their elimination by subsequent annealing in Al x Ga 1-x N/GaN heterostructures are systematically investigated.The energy levels of interface states with activation energies in a range from 0.211 to 0.253 eV below the conduction band of GaN are observed.The interface state density after the ICP-etching process is as high as 2.75×10 12 cm 2 ·eV 1.The ICP-induced interface states could be reduced by two orders of magnitude by subsequent annealing in N 2 ambient.The CL studies indicate that the ICP-induced defects should be Ga-vacancy related.     

分子束外延生长ZnSe自组织量子点光、电行为研究

分别应用光致发光、电容-电压和深能级瞬态傅里叶谱技术详细研究ZnSe自组织量子点样品的光学和电学行为.光致发光温度关系表明ZnSe量子点的光致发光热猝火过程机理.两步猝火过程的理论较好模拟和解释了相关的实验数据.电容-电压测量表明样品表观载流子积累峰出现的深度(样品表面下约100nm处)大约是ZnSe量子点层的位置.深能级瞬态傅里叶谱获得的ZnSe量子点电子基态能级位置为ZnSe导带下的0.11eV,这与ZnSe量子点光致发光热猝火模型得到的结果一致.     

分子束外延生长赝配高电子迁移率超高速微结构功能材料里深中心识别

应用深能级瞬态谱(DLTS)技术研究分子束外延(MBE)生长的highelectronmobilitytransistors(HEMT)和Pseudomorphichighelectronmobilitytransistors(PHEMT)结构深中心行为.样品的DLTS谱表明,在HEMT和PHEMT结构的nAlGaAs层里存在着较大浓度(1015-1017cm-3)和俘获截面(10-16cm2)的近禁带中部电子陷阱.它们可能与AlGaAs层的氧含量有关.同时还观察到PHEMT结构晶格不匹配的AlGaAsInGaAsGaAs系统在AlGaAs里产生的应力引起DX中心(与硅有关)能级位置的有序移动.其移动量可作为应力大小的一个判据,表明DLTS技术是定性识别此应力的可靠和简便的工具. 关键词： 分子束外延生长 高电子迁移率超高速微结构功能材料 深中心     

分子束外延生长AlGaAs/GaAs GRIN-SCH SQW激光器中高温陷阱的研究

应用深能级瞬态谱(DLTS)技术研究分子束外延(MBE)生长的AlGaAs/GaAs graded index separate confinement heterostructure single well(GRIN-SCH SQW)激光器的高温陷阱。样品的DLTS表明,在激光器的n-AlGaAs层里存在着高温(空穴、电子)陷阱,它直接影响着激光器的性能。高温空穴陷阱可能分布在x_Al =0.2→0.43和x_Al=0.43的n-AlGaAs层界面附近,而高温电子陷阱则可能分布在x_Al=0.43的n-AlGaAs层里x_Al值不连续的界面附近。高温电子陷阱的产生可能与AlGaAs层里的O有关。 关键词：     

分子束外延生长的赝配高电子迁移率晶体管结构中深能级的研究

应用深能级瞬态谱(DLTS)技术详细研究分子束外延生长的Pseudomorphic—high electron mobility transistor(P-HEMT)结构中深能级行为。样品的DLTS表明,在P-HEMT结构的n-AlGaAs层里存在着较大浓度(10¹⁵-10¹⁷cm^-3和俘获截面(10^-16cm²)的高温电子陷阱。它们直接影响着器件性能。高温电子陷阱的产生可能与AlGaAs层里的氧     

MBE和MOCVD生长的AlGaAs／GaAsGRIN—SCH SQW激光器深中心的比较

应用深能级瞬态谱（ＤＬＴＳ）技术详细研究分子束外延（ＭＢＥ）和金属有机物化学汽相淀积（ＭＯＣＶＤ）生长的ＡｌＧａＡｓ／ＧａＡｓ ｇｒａｄｅｄ ｉｎｄｅｘ ｓｅｐａｒａｔｅ ｃｏｎｆｉｎｅｍｅｎｔ ｈｅｔｅｒｏｓｔｒｕｃｔｕｒｅ ｓｉｎｇｌｅ ｑｕａｎｔｕｍ ｗｅｌｌ（ＧＲＩＮ－ＳＣＨ ＳＱＷ）激光器的深中心。结果表明，在激光器的ｎ－ＡｌＧａＡｓ层里除众所周知的ＤＸ中心外，还存在着较大浓度和俘获截面     

低压-金属有机物汽相外延生长的Ga1-xInxAs/InP激光器中深能级的研究

应用深能级瞬态谱（ＤＬＴｓ）技术详细研究低压－金属有机物汽相外延（ＬＰ－ＭＯＶＰＥ）生长的Ｇａ_０．４７Ｉｎ_０．５３Ａｓ／Ｉｎｐ量子阱、宽接触和质子轰击条形异质结激光器中的深能级。样品的ＤＬＴＳ表明，在宽接触激光器的ｉ－Ｇａ_０．４７Ｉｎ_０．５３Ａｓ有源层里观察到Ｈ１（Ｅ_ｖ＋０．０９ｅＶ）和Ｅ１（Ｅ_ｃ－０．３５ｅＶ)陷阱，它们可能分别与样品生长过程中扩散到ｉ－Ｇａ_{０．４ 关键词：}     

分子束外延生长AlGaAs/GaAs GRINSCH SQW激光器中高温陷阱的研究

应用深能级瞬态谱(DLTS)技术研究分子束外延(MBE)生长的AlGaAs/GaAs gradedindex separate confinement heterostructure single well(GRIN-SCH SQW)激光器的高温陷阱。样品的DLTS表明,在激光器的n-AlGaAs层里存在着高温(空穴、电子)陷阱,它直接影响着激光器的性能。高温空穴陷阱可能分布在x_(Al)=0.2→0.43和x_(Al)=0.43的n-AlGaAs层界面附近,而高温电子陷阱则可能分布在X_(Al)=0.43的n-AlGaAs层里X_(Al)值不连续的界面附近。高温电子陷阱的产生可能与AlGaAs层里的O有关。     

Leakage current reduction by thermal oxidation in Ni/Au Schottky contacts on lattice-matched Ino.18Al0.82N/GaN heterostructures

By using temperature-dependent current-voltage, variable-frequency capacitance-voltage, and Hall measurements, the effects of the thermal oxidation on the electrical properties of Ni/Au Schottky contacts on lattice-matched Ino.18Alo.82N/GaN heterostructures are investigated. Decrease of the reverse leakage current down to six orders of magni- tude is observed after the thermal oxidation of the Ino.18Alo.82N/GaN heterostructures at 700 ℃. It is confirmed that the reverse leakage current is dominated by the Frenkel-Poole emission, and the main origin of the leakage current is the emis- sion of electrons from a trap state near the metal/semiconductor interface into a continuum of electronic states associated with the conductive dislocations in the InxAll-xN barrier. It is believed that the thermal oxidation results in the formation of a thin oxide layer on the InxAll-xN surface, which increases the electron emission barrier height.     

分子束外延生长的n型Al掺杂ZnS1-xTex深中心研究

应用电容-电压、光致荧光和深能级瞬态谱技术研究了分子束外延生长的n型Al掺杂ZnS_1-xTe_x外延层深中心.Al掺杂ZnS_0.977Te_0.023的光致荧光强度明显低于不掺杂的ZnS_0.977Te_0.023，这表明一部分Al原子形成非辐射深中心.Al掺杂ZnS_1-xTe_x(x=0，0.017，0.04和0.046)的深能级瞬态傅里叶 关键词：