Voltage responsivity of bolometer will benefit from high temperature coefficient of resistance (TCR) of the material. The Nb5N6 thin solid films we proposed in this paper have high TCR, compared with the commonly-used...Voltage responsivity of bolometer will benefit from high temperature coefficient of resistance (TCR) of the material. The Nb5N6 thin solid films we proposed in this paper have high TCR, compared with the commonly-used materials such as Nb and Bi. The films were sputtered on Si(100), SiO2/Si(100), SiO2 substrates by using radio frequency (rf) magnetron sputtering. The deposition conditions have been optimized to get high TCR. The highest TCR is over 0.91% K-1 at 300 K and up to 4.5% K -1―7% K-1 at 78 K, which is good enough to be used in terahertz detection and thermometer fabrication in the range from 78 K to 300 K.展开更多
The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive positi...The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.展开更多
Square ZnO nano-columns have been manufactured by molecular beam epitaxy on p-type Si (100) substrate. The morphology and the evolution sequences after thermal annealing were investigated by in-situ scanning tunneling...Square ZnO nano-columns have been manufactured by molecular beam epitaxy on p-type Si (100) substrate. The morphology and the evolution sequences after thermal annealing were investigated by in-situ scanning tunneling microscopy. We associated the morphology and microstructure evolution with the cubic Si (100) substrate, large lattice mismatching, the coexistence of wurtzite and zincblende phases of ZnO, and the thermal effect.展开更多
Fe-doped amorphous FexCl~ granular films were prepared on n-Si (100) substrates by d.c. magnetron sputtering. The structur- al properties of FexC1-x films were investigated by X-ray diffraction (XRD), atomic force...Fe-doped amorphous FexCl~ granular films were prepared on n-Si (100) substrates by d.c. magnetron sputtering. The structur- al properties of FexC1-x films were investigated by X-ray diffraction (XRD), atomic force microscope (AFM) and Raman spec- troscopy. The results show that the iron and carbon of as-deposited films are in amorphous state, and the FexC1-x films are di- amond-like carbon (DLC) films. After doping iron into the DLC films, a smooth surface morphology of the FexC1-x films has been obtained with the surface roughness Ra of about 0.231 nm for x=18at%. The FexC1-x films have good soft magnetic prop- erties with the coercivity of approximately 20 Oe. A high positive magnetoresistance (MR) up to 93% with x=lat% was ob- served in a FexCl-x granular film at 300 K. The resistance characteristic of Fe-C films is changed at about 230 K and the positive MR effect can be understood by the p-n heterojunction theory.展开更多
Er2O3 thin films are grown on oxidized Si (111) substrates by molecular beam epitaxy. The sample grown under optimized condition is characterized in its microstructure, surface morphology and thickness using grazing...Er2O3 thin films are grown on oxidized Si (111) substrates by molecular beam epitaxy. The sample grown under optimized condition is characterized in its microstructure, surface morphology and thickness using grazing incidence x-ray diffraction (GIXRD), atomic force morphology and x-ray reflectivity. GIXRD measurements reveal that the Er2O3 thin film is a mosaic of single-crystal domains. The interplanar spacing d in-plane residual strain tensor ell and the strain relaxation degree ε are calculated. The Poisson ratio μ obtained by conventional x-ray diffraction is in good agreement with that of the bulk Er2O3. In-plane strains in three sets of planes, i.e. (440), (404), and (044), are isotropic.展开更多
We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide (WS2) films. The WS2 films were deposited on a Si (100) substrate and a zinc sulfide (ZnS) film coated the Si (100) subs...We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide (WS2) films. The WS2 films were deposited on a Si (100) substrate and a zinc sulfide (ZnS) film coated the Si (100) substrate using tungsten hexacarbonyl and hydrogen sulfide as precursors. The ZnS film served as an intermediate layer to facilitate the nucleation and growth of the WS2 films. The thickness of the WS2 films was measured via scanning electron microscope, the microstructure was probed with an X-ray diffractometer and a transmission electron microscope. The friction coefficient was measured with a ball-on-disk tester under dry nitrogen. The results reveal that the WS2 films deposited on both substrates are N175 nm and have (002) and (101) crystal orientations. The WS2 film deposited on the ZnS coated Si substrate exhibits a stronger (002) orientation and a denser crystal structure than that deposited on the Si substrate. The WS2 films on both substrates have low friction coefficients. How- ever, due to the stronger (002) orientation and denser crystal structure, the friction coefficient of the WS2 film deposited on ZnS coated Si substrate is smaller with longer wear life.展开更多
We have studied the interracial reactions between amorphous LaAlO3 thin films and Si substrates, using high- resolution transmission electron microscopy and x-ray photoelectron spectroscopy. It has been shown that the...We have studied the interracial reactions between amorphous LaAlO3 thin films and Si substrates, using high- resolution transmission electron microscopy and x-ray photoelectron spectroscopy. It has been shown that the interracial layer between LaAlO3 film and Si substrate chemical states show that the ratio of La 4d3/2 to Al 2p is SiLaxAlyOz. The depth distributions of La, Si and Al of the interfacial layer remains unchanged with the depth compared to that of the LaAlO3 film. Moreover, the Si content, in the interracial layer gradually decreases with increasing thickness of the interracial layer. These results strongly suggest that the Al element is not deficient in the interracial layer, as previously believed, and the formation of a SiLaxAlyOz interracial layer is mainly due to the diffusion of Si from the substrate during the LaAlO3 film deposition. With the understanding of the interracial layer formation, ones can control the interface characteristics to ensure the desired performances of devices using high-k oxides as gate dielectrics.展开更多
An ion beam analysis system was established on a 1.7 MV tandem accelerator, enabling Rutherford backscattering(RBS), elastic recoil detection(ERD), nuclear reaction analysis(NRA) and channeling measurements. The syste...An ion beam analysis system was established on a 1.7 MV tandem accelerator, enabling Rutherford backscattering(RBS), elastic recoil detection(ERD), nuclear reaction analysis(NRA) and channeling measurements. The system was tested by performing qualitative and quantitative analysis of Si, Ni/Si, Bi Fe O3:La/Si,Mo C/Mo/Si and Ti BN/Si samples. RBS of a Bi Fe O3:La film was used as system calibration. Tested by ion beam channeling, a Si(100) is of good crystallinity(χmin= 3.01%). For thin film samples, the measured thickness agrees well with simulation results by SIMNRA. In particular, composition of a Mo C/Mo/Si and Ti BN film samples were analyzed by RBS and non-Rutherford elastic backscattering.展开更多
CrN coatings were deposited on Si(100) and piston rings by ion source assisted 40 kHz magnetron sputtering.Structure and composition of the coatings were characterized by X-ray diffraction,atomic force microscopy,scan...CrN coatings were deposited on Si(100) and piston rings by ion source assisted 40 kHz magnetron sputtering.Structure and composition of the coatings were characterized by X-ray diffraction,atomic force microscopy,scanning electron microscopy and transmission electron microscopy.Mechanical and tribological properties were assessed by microhardness and pin-on-disc testing.The ion source-assisted system has a deposition rate of 3.88 μm/h,against 2.2 μm/h without ion-source assistance.The CrN coatings prepared with ion source assistance exhibited an increase in microhardness(up to 16.3 GPa) and decrease in friction coefficient(down to 0.48) at the optimized cathode source-to-substrate distance.Under optimized conditions,CrN coatings were deposited on piston rings,with a thickness of 25 μm and hardness of 17.85 GPa.展开更多
基金Supported by the National Basic Research Programme of China (Grant Nos. 2006CB601006 and 2007CB310404)National High-Tech R&D Programme of China (Grant No. 2006AA12Z120)National Natural Science Foundation of China (NSFC) (Grant Nos. 10778602 and 60721063)
文摘Voltage responsivity of bolometer will benefit from high temperature coefficient of resistance (TCR) of the material. The Nb5N6 thin solid films we proposed in this paper have high TCR, compared with the commonly-used materials such as Nb and Bi. The films were sputtered on Si(100), SiO2/Si(100), SiO2 substrates by using radio frequency (rf) magnetron sputtering. The deposition conditions have been optimized to get high TCR. The highest TCR is over 0.91% K-1 at 300 K and up to 4.5% K -1―7% K-1 at 78 K, which is good enough to be used in terahertz detection and thermometer fabrication in the range from 78 K to 300 K.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61574171,61704127,11875229,51872251,and 12027813)。
文摘The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.
基金supported by the Natural Science Foundation of Fujian Province (Grant No. 2009J01267)
文摘Square ZnO nano-columns have been manufactured by molecular beam epitaxy on p-type Si (100) substrate. The morphology and the evolution sequences after thermal annealing were investigated by in-situ scanning tunneling microscopy. We associated the morphology and microstructure evolution with the cubic Si (100) substrate, large lattice mismatching, the coexistence of wurtzite and zincblende phases of ZnO, and the thermal effect.
基金supported by the National Natural Science Foundation of China (Grant No. U0734001)the Fundamental Research Funds for the Central Universities,SCUT (Grant Nos. 2009ZM0247 and 2012ZZ0015)
文摘Fe-doped amorphous FexCl~ granular films were prepared on n-Si (100) substrates by d.c. magnetron sputtering. The structur- al properties of FexC1-x films were investigated by X-ray diffraction (XRD), atomic force microscope (AFM) and Raman spec- troscopy. The results show that the iron and carbon of as-deposited films are in amorphous state, and the FexC1-x films are di- amond-like carbon (DLC) films. After doping iron into the DLC films, a smooth surface morphology of the FexC1-x films has been obtained with the surface roughness Ra of about 0.231 nm for x=18at%. The FexC1-x films have good soft magnetic prop- erties with the coercivity of approximately 20 Oe. A high positive magnetoresistance (MR) up to 93% with x=lat% was ob- served in a FexCl-x granular film at 300 K. The resistance characteristic of Fe-C films is changed at about 230 K and the positive MR effect can be understood by the p-n heterojunction theory.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10174081 and 60425411.
文摘Er2O3 thin films are grown on oxidized Si (111) substrates by molecular beam epitaxy. The sample grown under optimized condition is characterized in its microstructure, surface morphology and thickness using grazing incidence x-ray diffraction (GIXRD), atomic force morphology and x-ray reflectivity. GIXRD measurements reveal that the Er2O3 thin film is a mosaic of single-crystal domains. The interplanar spacing d in-plane residual strain tensor ell and the strain relaxation degree ε are calculated. The Poisson ratio μ obtained by conventional x-ray diffraction is in good agreement with that of the bulk Er2O3. In-plane strains in three sets of planes, i.e. (440), (404), and (044), are isotropic.
基金supported by the National Natural Science Fundation of China(Grant Nos.50825501,51321092&51335005)the National Science and Technology Major Project(Grant No.2008ZX02104-001)
文摘We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide (WS2) films. The WS2 films were deposited on a Si (100) substrate and a zinc sulfide (ZnS) film coated the Si (100) substrate using tungsten hexacarbonyl and hydrogen sulfide as precursors. The ZnS film served as an intermediate layer to facilitate the nucleation and growth of the WS2 films. The thickness of the WS2 films was measured via scanning electron microscope, the microstructure was probed with an X-ray diffractometer and a transmission electron microscope. The friction coefficient was measured with a ball-on-disk tester under dry nitrogen. The results reveal that the WS2 films deposited on both substrates are N175 nm and have (002) and (101) crystal orientations. The WS2 film deposited on the ZnS coated Si substrate exhibits a stronger (002) orientation and a denser crystal structure than that deposited on the Si substrate. The WS2 films on both substrates have low friction coefficients. How- ever, due to the stronger (002) orientation and denser crystal structure, the friction coefficient of the WS2 film deposited on ZnS coated Si substrate is smaller with longer wear life.
文摘We have studied the interracial reactions between amorphous LaAlO3 thin films and Si substrates, using high- resolution transmission electron microscopy and x-ray photoelectron spectroscopy. It has been shown that the interracial layer between LaAlO3 film and Si substrate chemical states show that the ratio of La 4d3/2 to Al 2p is SiLaxAlyOz. The depth distributions of La, Si and Al of the interfacial layer remains unchanged with the depth compared to that of the LaAlO3 film. Moreover, the Si content, in the interracial layer gradually decreases with increasing thickness of the interracial layer. These results strongly suggest that the Al element is not deficient in the interracial layer, as previously believed, and the formation of a SiLaxAlyOz interracial layer is mainly due to the diffusion of Si from the substrate during the LaAlO3 film deposition. With the understanding of the interracial layer formation, ones can control the interface characteristics to ensure the desired performances of devices using high-k oxides as gate dielectrics.
基金Supported by the National Natural Science Foundation of China(No.11405117)the State Key Lab of Advanced Welding and Joining of Harbin Institute of Technology(No.AWJ-M13-03)
文摘An ion beam analysis system was established on a 1.7 MV tandem accelerator, enabling Rutherford backscattering(RBS), elastic recoil detection(ERD), nuclear reaction analysis(NRA) and channeling measurements. The system was tested by performing qualitative and quantitative analysis of Si, Ni/Si, Bi Fe O3:La/Si,Mo C/Mo/Si and Ti BN/Si samples. RBS of a Bi Fe O3:La film was used as system calibration. Tested by ion beam channeling, a Si(100) is of good crystallinity(χmin= 3.01%). For thin film samples, the measured thickness agrees well with simulation results by SIMNRA. In particular, composition of a Mo C/Mo/Si and Ti BN film samples were analyzed by RBS and non-Rutherford elastic backscattering.
基金Supported by the Ministry of Industry and Information Technology (No. 2009ZX04012-032)
文摘CrN coatings were deposited on Si(100) and piston rings by ion source assisted 40 kHz magnetron sputtering.Structure and composition of the coatings were characterized by X-ray diffraction,atomic force microscopy,scanning electron microscopy and transmission electron microscopy.Mechanical and tribological properties were assessed by microhardness and pin-on-disc testing.The ion source-assisted system has a deposition rate of 3.88 μm/h,against 2.2 μm/h without ion-source assistance.The CrN coatings prepared with ion source assistance exhibited an increase in microhardness(up to 16.3 GPa) and decrease in friction coefficient(down to 0.48) at the optimized cathode source-to-substrate distance.Under optimized conditions,CrN coatings were deposited on piston rings,with a thickness of 25 μm and hardness of 17.85 GPa.