The carrier transport mechanism of Mg/Au ohmic contact for lightly doped β-Ga_2O_3 is investigated. An excellent ohmic contact has been achieved when the sample was annealed at 400 °C and the specific contact re...The carrier transport mechanism of Mg/Au ohmic contact for lightly doped β-Ga_2O_3 is investigated. An excellent ohmic contact has been achieved when the sample was annealed at 400 °C and the specific contact resistance is 4.3 × 10-4 Ω·cm2. For the annealed sample, the temperature dependence of specific contact resistance is studied in the range from 300 to 375 K. The specific contact resistance is decreased from 4.3 × 10-4 to 1.59 × 10-4 Ω·cm2 with an increase of test temperature. As combination with the judge of E00, the basic mechanism of current transport is dominant by thermionic emission theory. The effective barrier height between Mg/Au and β-Ga_2O_3 is evaluated to be 0.1 eV for annealed sample by fitting experimental data with thermionic emission model.展开更多
以Ti/Al/Ni/Au作为欧姆接触金属体系,通过电感耦合等离子体(ICP)刻蚀的预处理,在氢化物气相外延法生长的单晶氮化镓(GaN)材料的N面实现了良好的欧姆接触,其比接触电阻率为3.7×10-4Ω·cm^2。通过扫描电子显微镜、原子力显微镜...以Ti/Al/Ni/Au作为欧姆接触金属体系,通过电感耦合等离子体(ICP)刻蚀的预处理,在氢化物气相外延法生长的单晶氮化镓(GaN)材料的N面实现了良好的欧姆接触,其比接触电阻率为3.7×10-4Ω·cm^2。通过扫描电子显微镜、原子力显微镜、阴极荧光和光致发光谱对GaN N面的表面、光学特性进行了对比表征。结果表明:未刻蚀GaN衬底的N面表面存在一定的损伤层,导致近表面处含有大量缺陷,不利于欧姆接触的形成;而ICP刻蚀处理有效地去除了损伤层。X射线光电子能谱(XPS)分析显示刻蚀后样品的Ga 3d结合能比未刻蚀样品向高能方向移动了约0.3 e V,其肖特基势垒则相应降低,有利于欧姆接触的形成。同时对Fe掺杂半绝缘GaN的N面也进行了刻蚀处理,同样实现了良好的Ti/Al/Ni/Au欧姆接触,其比接触电阻率为0.12Ω·cm^2。展开更多
基金supported by the National Key R&D Plan(Nos.2016YFB0400600,2016YFB0400601)the National Science Foundation of China(Nos.11675198,61376046,11405017,61574026)+3 种基金the Fundamental Research Funds for t he Central Universities(Nos.DUT15LK15,DUT15RC(3)016,NoDUT16LK29)the Liaoning Provincial Natural Science Foundation of China(Nos.2014020004,201602453,201602176)the China Postdoctoral Science Foundation Funded Project(No.2016M591434)the Open Fund of the State Key Laboratory on Integrated Optoelectronics(Nos.IOSKL2015KF18,IOSKL2015KF22)
文摘The carrier transport mechanism of Mg/Au ohmic contact for lightly doped β-Ga_2O_3 is investigated. An excellent ohmic contact has been achieved when the sample was annealed at 400 °C and the specific contact resistance is 4.3 × 10-4 Ω·cm2. For the annealed sample, the temperature dependence of specific contact resistance is studied in the range from 300 to 375 K. The specific contact resistance is decreased from 4.3 × 10-4 to 1.59 × 10-4 Ω·cm2 with an increase of test temperature. As combination with the judge of E00, the basic mechanism of current transport is dominant by thermionic emission theory. The effective barrier height between Mg/Au and β-Ga_2O_3 is evaluated to be 0.1 eV for annealed sample by fitting experimental data with thermionic emission model.
文摘以Ti/Al/Ni/Au作为欧姆接触金属体系,通过电感耦合等离子体(ICP)刻蚀的预处理,在氢化物气相外延法生长的单晶氮化镓(GaN)材料的N面实现了良好的欧姆接触,其比接触电阻率为3.7×10-4Ω·cm^2。通过扫描电子显微镜、原子力显微镜、阴极荧光和光致发光谱对GaN N面的表面、光学特性进行了对比表征。结果表明:未刻蚀GaN衬底的N面表面存在一定的损伤层,导致近表面处含有大量缺陷,不利于欧姆接触的形成;而ICP刻蚀处理有效地去除了损伤层。X射线光电子能谱(XPS)分析显示刻蚀后样品的Ga 3d结合能比未刻蚀样品向高能方向移动了约0.3 e V,其肖特基势垒则相应降低,有利于欧姆接触的形成。同时对Fe掺杂半绝缘GaN的N面也进行了刻蚀处理,同样实现了良好的Ti/Al/Ni/Au欧姆接触,其比接触电阻率为0.12Ω·cm^2。
