采用反应沉积外延法在723K的Si(111)衬底上共沉积了的Ba/Si混合膜,通过时间控制得到不同厚度的混合膜,然后真空退火处理。X射线衍射表明在真空中1073K退火12小时后出现了单一的Ba5Si3薄膜。采用第一性原理对Ba5Si3的能带结构进行了计算...采用反应沉积外延法在723K的Si(111)衬底上共沉积了的Ba/Si混合膜,通过时间控制得到不同厚度的混合膜,然后真空退火处理。X射线衍射表明在真空中1073K退火12小时后出现了单一的Ba5Si3薄膜。采用第一性原理对Ba5Si3的能带结构进行了计算,带隙宽度为0 e V,表现为金属性质。展开更多
Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements a...Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements are used to investigate the crystallinity of the grown films.Electrical properties of the epitaxial 3C-SiC layers with thickness of 1～3μm are measured by Van der Pauw method.The improved Hall mobility reaches the highest value of 470cm 2/(V·s) at the carrier concentration of 7.7×10 17 cm -3 .展开更多
High quality GaN is grown on GaN substrate with stripe pattern by metalorganic chemical vapor deposition by means of epitaxial lateral overgrowth. AFM,wet chemical etching, and TEM experiments show that with a two-ste...High quality GaN is grown on GaN substrate with stripe pattern by metalorganic chemical vapor deposition by means of epitaxial lateral overgrowth. AFM,wet chemical etching, and TEM experiments show that with a two-step ELOG procedure, the propagation of defects under the mask is blocked, and the coherently grown GaN above the window also experiences a drastic reduction in defect density. In addition, a grain boundary is formed at the coalescence boundary of neighboring growth fronts. The extremely low density of threading dislocations within wing regions makes ELOG GaN a potential template for the fabrication of nitride-based lasers with improved performance.展开更多
Reducing the module prices by increasing the efficiency of solar cells is one of the major challenges in today＇s photovoltaic research. The emitter formation by epitaxial growth offers a cost-efficient and faster alt...Reducing the module prices by increasing the efficiency of solar cells is one of the major challenges in today＇s photovoltaic research. The emitter formation by epitaxial growth offers a cost-efficient and faster alternative to the standard furnace diffusion process. The efficiency potential of epitaxial emitters 〉 22% has already been proven using a single wafer, low pressure, chemical vapour deposition tool. The purpose of this work is to show the potential of epitaxially grown emitters by APCVD （atmospheric pressure chemical vapour deposition） compared to diffused emitters. The APCVD formation of epitaxial emitters at 1,050 ~C can be realised as high throughput inline process and only takes 1-2 min, whereas the diffusion process using POCI3 takes up to 60 min. Simulations show an increase in voltage of AVoc = ＋10 mV and a reduction in saturation current ,1o of 30% for the epitaxial emitter. The lifetime experiments of solar cells with epitaxial emitter exhibit a diffusion length Leff〉 750μm and an emitter saturation current of Joe 〈 50 fA/cm2 on a planar 10 Ω2cm p-type FZ wafer. Another important aim of this work is to evaluate the limitations of epitaxial emitters due to high thermal budget, interface recombination and the change of reflective properties on textured wafers due to the deposition process. Solar cell efficiencies up to 18.4% on p-type and 20.0% on n-type wafers presented in this paper underline that the emitter epitaxy by APCVD is a competitive process for the emitter formation.展开更多
新的NMOS(N型金属氧化物半导体)外延沉积工艺对下一代移动处理器芯片内更快的晶体管至关重要应用材料公司在Applied Centura RP Epi系统设备上新开发了一套NMOS晶体管应用技术,继续保持其在外延技术方面十年来的领先地位。该应用技术的...新的NMOS(N型金属氧化物半导体)外延沉积工艺对下一代移动处理器芯片内更快的晶体管至关重要应用材料公司在Applied Centura RP Epi系统设备上新开发了一套NMOS晶体管应用技术,继续保持其在外延技术方面十年来的领先地位。该应用技术的开发符合行业在20纳米节点时将外延沉积从PMOS(P型金属氧化物半导体)向NMOS(N型金属氧化物半导体)晶体管延伸的趋势,推动芯片制造商打造出更快的终端,提供下一代移动计算能力。NMOS外延可将晶体管速度提高半个器件节点,同时不增加关闭状态下的功耗"外延是高性能晶体管的基本组成部分。展开更多
Epitaxial growth of SmFeO3/SrRuO3 was achieved on SrTiO3 substrates by the pulsed laser deposition(PLD)method at 973 K under oxygen partial pressure of 12.5 Pa.No Fe2+leakage was detected in our SmFeO3 film.The remane...Epitaxial growth of SmFeO3/SrRuO3 was achieved on SrTiO3 substrates by the pulsed laser deposition(PLD)method at 973 K under oxygen partial pressure of 12.5 Pa.No Fe2+leakage was detected in our SmFeO3 film.The remanent polarization and coercive electric field of the thin film with a higher degree of orientation along(110)were 1.97μC/cm2 and 0.89×104 V/cm at room temperature,respectively.This film showed enhanced canted antiferromagnetism spin ordering compared with its corresponding powder materials.展开更多
Field plate(FP)-terminated 4H-SiC trench gate MOSFETs are demonstrated in this work.N+/P?/N?/N+multiple epitaxial layers were grown on 3-inch N+type 4H-SiC substrate by chemical vapor deposition(CVD),and then the 4H-S...Field plate(FP)-terminated 4H-SiC trench gate MOSFETs are demonstrated in this work.N+/P?/N?/N+multiple epitaxial layers were grown on 3-inch N+type 4H-SiC substrate by chemical vapor deposition(CVD),and then the 4H-SiC trench gate MOSFETs were fabricated based on the standard trench transistor fabrication.Current-voltage measurements in forward and reverse bias have been performed on different devices with and without FP protections.It is found that more than 60%of the devices protected with FP termination are able to block 850 V.The measurements also show that the devices have the small leakage currents 0.15 nA at 600 V and 2.5 nA at 800 V,respectively.The experimental results also were compared with the simulated results,which show good agreement with each other in the trend.The limited performance of the devices is mainly because of the damage induced on the trench sidewalls from the etching process and the quality of the SiO2 films.Therefore,the 4H-SiC trench gate MOSFETs are expected to be optimized by reducing the etching damage and growing high-quality SiO2 dielectric films.展开更多
Orthorhombic HoMnO3(HMO) thin films were grown epitaxially on LaAlO3(001) substrates by using pulsed laser deposition technique. The films showed perfect orthorhombic crystallization and were well-aligned with the sub...Orthorhombic HoMnO3(HMO) thin films were grown epitaxially on LaAlO3(001) substrates by using pulsed laser deposition technique. The films showed perfect orthorhombic crystallization and were well-aligned with the substrates. The in-plane dielectric constant and loss of HMO films were measured as functions of temperature(80–300 K) and frequency(120 Hz–100 kHz) by using coplanar interdigital electrodes. Two thermally activated dielectric relaxations were found, and the respective peaks shifted to higher temperatures as the measuring frequency increased. The in-plane dielectric properties of epitaxial orthorhombic HMO films were considered as universal dielectric response behavior, and the dipolar effects and the hopping conductivity induced by the charge carriers were used to explain the results.展开更多
文摘Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements are used to investigate the crystallinity of the grown films.Electrical properties of the epitaxial 3C-SiC layers with thickness of 1～3μm are measured by Van der Pauw method.The improved Hall mobility reaches the highest value of 470cm 2/(V·s) at the carrier concentration of 7.7×10 17 cm -3 .
文摘High quality GaN is grown on GaN substrate with stripe pattern by metalorganic chemical vapor deposition by means of epitaxial lateral overgrowth. AFM,wet chemical etching, and TEM experiments show that with a two-step ELOG procedure, the propagation of defects under the mask is blocked, and the coherently grown GaN above the window also experiences a drastic reduction in defect density. In addition, a grain boundary is formed at the coalescence boundary of neighboring growth fronts. The extremely low density of threading dislocations within wing regions makes ELOG GaN a potential template for the fabrication of nitride-based lasers with improved performance.
文摘Reducing the module prices by increasing the efficiency of solar cells is one of the major challenges in today＇s photovoltaic research. The emitter formation by epitaxial growth offers a cost-efficient and faster alternative to the standard furnace diffusion process. The efficiency potential of epitaxial emitters 〉 22% has already been proven using a single wafer, low pressure, chemical vapour deposition tool. The purpose of this work is to show the potential of epitaxially grown emitters by APCVD （atmospheric pressure chemical vapour deposition） compared to diffused emitters. The APCVD formation of epitaxial emitters at 1,050 ~C can be realised as high throughput inline process and only takes 1-2 min, whereas the diffusion process using POCI3 takes up to 60 min. Simulations show an increase in voltage of AVoc = ＋10 mV and a reduction in saturation current ,1o of 30% for the epitaxial emitter. The lifetime experiments of solar cells with epitaxial emitter exhibit a diffusion length Leff〉 750μm and an emitter saturation current of Joe 〈 50 fA/cm2 on a planar 10 Ω2cm p-type FZ wafer. Another important aim of this work is to evaluate the limitations of epitaxial emitters due to high thermal budget, interface recombination and the change of reflective properties on textured wafers due to the deposition process. Solar cell efficiencies up to 18.4% on p-type and 20.0% on n-type wafers presented in this paper underline that the emitter epitaxy by APCVD is a competitive process for the emitter formation.
文摘新的NMOS(N型金属氧化物半导体)外延沉积工艺对下一代移动处理器芯片内更快的晶体管至关重要应用材料公司在Applied Centura RP Epi系统设备上新开发了一套NMOS晶体管应用技术,继续保持其在外延技术方面十年来的领先地位。该应用技术的开发符合行业在20纳米节点时将外延沉积从PMOS(P型金属氧化物半导体)向NMOS(N型金属氧化物半导体)晶体管延伸的趋势,推动芯片制造商打造出更快的终端,提供下一代移动计算能力。NMOS外延可将晶体管速度提高半个器件节点,同时不增加关闭状态下的功耗"外延是高性能晶体管的基本组成部分。
基金supported by the National Natural Science Foundation of China(90922034,21131002,and 21201075)the Specialized Research Fund for the Doctoral Program of Higher Education(20110061130005)
文摘Epitaxial growth of SmFeO3/SrRuO3 was achieved on SrTiO3 substrates by the pulsed laser deposition(PLD)method at 973 K under oxygen partial pressure of 12.5 Pa.No Fe2+leakage was detected in our SmFeO3 film.The remanent polarization and coercive electric field of the thin film with a higher degree of orientation along(110)were 1.97μC/cm2 and 0.89×104 V/cm at room temperature,respectively.This film showed enhanced canted antiferromagnetism spin ordering compared with its corresponding powder materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.61176070,61274079)the Natural Science Foundation of Shaanxi Province(Grant No.2013JQ8012)+1 种基金the Doctoral Fund of Ministry of Education of China(Grant Nos.20110203110010,201302031-0017)the Key Specific Projects of Ministry of Education of China(Grant No.625010101)
文摘Field plate(FP)-terminated 4H-SiC trench gate MOSFETs are demonstrated in this work.N+/P?/N?/N+multiple epitaxial layers were grown on 3-inch N+type 4H-SiC substrate by chemical vapor deposition(CVD),and then the 4H-SiC trench gate MOSFETs were fabricated based on the standard trench transistor fabrication.Current-voltage measurements in forward and reverse bias have been performed on different devices with and without FP protections.It is found that more than 60%of the devices protected with FP termination are able to block 850 V.The measurements also show that the devices have the small leakage currents 0.15 nA at 600 V and 2.5 nA at 800 V,respectively.The experimental results also were compared with the simulated results,which show good agreement with each other in the trend.The limited performance of the devices is mainly because of the damage induced on the trench sidewalls from the etching process and the quality of the SiO2 films.Therefore,the 4H-SiC trench gate MOSFETs are expected to be optimized by reducing the etching damage and growing high-quality SiO2 dielectric films.
基金supported by Shandong Province Natural Science Foundation of China(Grant No.ZR2011AM014)
文摘Orthorhombic HoMnO3(HMO) thin films were grown epitaxially on LaAlO3(001) substrates by using pulsed laser deposition technique. The films showed perfect orthorhombic crystallization and were well-aligned with the substrates. The in-plane dielectric constant and loss of HMO films were measured as functions of temperature(80–300 K) and frequency(120 Hz–100 kHz) by using coplanar interdigital electrodes. Two thermally activated dielectric relaxations were found, and the respective peaks shifted to higher temperatures as the measuring frequency increased. The in-plane dielectric properties of epitaxial orthorhombic HMO films were considered as universal dielectric response behavior, and the dipolar effects and the hopping conductivity induced by the charge carriers were used to explain the results.
