利用交流磁控溅射法，在H2中采用Fe3O4靶材，成功制备了（111）取向的Fe3O4薄膜．对薄膜样品进行XRD测试，研究不同衬底温度对成相的影响．对薄膜表面的XPS测试结果表明所制备薄膜为单相Fe3O4，沉积过程中随H2量增大，薄膜表面粗糙度有...利用交流磁控溅射法，在H2中采用Fe3O4靶材，成功制备了（111）取向的Fe3O4薄膜．对薄膜样品进行XRD测试，研究不同衬底温度对成相的影响．对薄膜表面的XPS测试结果表明所制备薄膜为单相Fe3O4，沉积过程中随H2量增大，薄膜表面粗糙度有显著增加．对薄膜进行磁学性能的测试，饱和磁化强度高达50000e，反映了反相晶粒边界（APBs）的存在，Tv以下较低的晶格对称度导致了矫顽场的增大，薄膜的电阻随温度变化曲线（R—n显示115K附近出现Verwey相变，对R—T曲线的拟和结果显示，Fe3O4；薄膜在40～300K温度区间为电子的变程跳跃VRH（Variable range hopping）导电机制。展开更多
The transport mechanism of reverse surface leakage current in the AlGaN/GaN high-electron mobility transistor（HEMT） becomes one of the most important reliability issues with the downscaling of feature size.In this p...The transport mechanism of reverse surface leakage current in the AlGaN/GaN high-electron mobility transistor（HEMT） becomes one of the most important reliability issues with the downscaling of feature size.In this paper,the research results show that the reverse surface leakage current in AlGaN/GaN HEMT with SiN passivation increases with the enhancement of temperature in the range from 298 K to 423 K.Three possible transport mechanisms are proposed and examined to explain the generation of reverse surface leakage current.By comparing the experimental data with the numerical transport models,it is found that neither Fowler-Nordheim tunneling nor Frenkel-Poole emission can describe the transport of reverse surface leakage current.However,good agreement is found between the experimental data and the two-dimensional variable range hopping（2D-VRH） model.Therefore,it is concluded that the reverse surface leakage current is dominated by the electron hopping through the surface states at the barrier layer.Moreover,the activation energy of surface leakage current is extracted,which is around 0.083 eV.Finally,the SiN passivated HEMT with a high Al composition and a thin AlGaN barrier layer is also studied.It is observed that 2D-VRH still dominates the reverse surface leakage current and the activation energy is around 0.10 eV,which demonstrates that the alteration of the AlGaN barrier layer does not affect the transport mechanism of reverse surface leakage current in this paper.展开更多
文摘利用交流磁控溅射法，在H2中采用Fe3O4靶材，成功制备了（111）取向的Fe3O4薄膜．对薄膜样品进行XRD测试，研究不同衬底温度对成相的影响．对薄膜表面的XPS测试结果表明所制备薄膜为单相Fe3O4，沉积过程中随H2量增大，薄膜表面粗糙度有显著增加．对薄膜进行磁学性能的测试，饱和磁化强度高达50000e，反映了反相晶粒边界（APBs）的存在，Tv以下较低的晶格对称度导致了矫顽场的增大，薄膜的电阻随温度变化曲线（R—n显示115K附近出现Verwey相变，对R—T曲线的拟和结果显示，Fe3O4；薄膜在40～300K温度区间为电子的变程跳跃VRH（Variable range hopping）导电机制。
基金supported by the National Natural Science Foundation of China(Grant Nos.61334002,61106106,and 61474091)the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory,China(Grant No.ZHD201206)+3 种基金the New Experiment Development Funds for Xidian University,China(Grant No.SY1213)the 111 Project,China(Grant No.B12026)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,Chinathe Fundamental Research Funds for the Central Universities,China(Grant No.K5051325002)
文摘The transport mechanism of reverse surface leakage current in the AlGaN/GaN high-electron mobility transistor（HEMT） becomes one of the most important reliability issues with the downscaling of feature size.In this paper,the research results show that the reverse surface leakage current in AlGaN/GaN HEMT with SiN passivation increases with the enhancement of temperature in the range from 298 K to 423 K.Three possible transport mechanisms are proposed and examined to explain the generation of reverse surface leakage current.By comparing the experimental data with the numerical transport models,it is found that neither Fowler-Nordheim tunneling nor Frenkel-Poole emission can describe the transport of reverse surface leakage current.However,good agreement is found between the experimental data and the two-dimensional variable range hopping（2D-VRH） model.Therefore,it is concluded that the reverse surface leakage current is dominated by the electron hopping through the surface states at the barrier layer.Moreover,the activation energy of surface leakage current is extracted,which is around 0.083 eV.Finally,the SiN passivated HEMT with a high Al composition and a thin AlGaN barrier layer is also studied.It is observed that 2D-VRH still dominates the reverse surface leakage current and the activation energy is around 0.10 eV,which demonstrates that the alteration of the AlGaN barrier layer does not affect the transport mechanism of reverse surface leakage current in this paper.
