In this report, the effect of temperature on the In As/Al Sb heterojunction and high-electron-mobility transistors（HEMTs） with a gate length of 2 μm are discussed comprehensively. The results indicate that device p...In this report, the effect of temperature on the In As/Al Sb heterojunction and high-electron-mobility transistors（HEMTs） with a gate length of 2 μm are discussed comprehensively. The results indicate that device performance is greatly improved at cryogenic temperatures. It is also observed that the device performance at 90 K is significantly improved with 27% lower gate leakage current, 12% higher maximum drain current, and 22.5% higher peak transconductance compared to 300 K. The temperature dependence of mobility and the two-dimensional electron gas concentration in the In As/Al Sb heterojunction for the temperature range 90 K-300 K is also investigated. The electron mobility at 90 K（42560 cm2/V·s）is 2.5 times higher than its value at 300 K（16911 cm^2/V·s） because of the weaker lattice vibration and the impurity ionization at cryogenic temperatures, which corresponds to a reduced scattering rate and higher mobility. We also noted that the two-dimensional electron gas concentration decreases slightly from 1.99 × 10^（12） cm^（-2） at 300 K to 1.7 × 10^（12） cm^（-2） at 90 K with a decrease in temperature due to the lower ionization at cryogenic temperature and the nearly constant ？Ec.展开更多
One-band effective mass model is used to simulation of electron gas properties in quantum well. We calculate of dispersion curves for first three subbands. Calculation results of Fermi energy, effective mass at Fermi ...One-band effective mass model is used to simulation of electron gas properties in quantum well. We calculate of dispersion curves for first three subbands. Calculation results of Fermi energy, effective mass at Fermi level as function of electron concentration are presented. The obtained results are good agreement with the experimental dates.展开更多
lnA1N/GaN high-electron-mobility transistors （HEMTs） on SiC substrate were fabricated and character- ized. Several techniques, consisting of high electron density, 70 nm T-shaped gate, low ohmic contacts and a short...lnA1N/GaN high-electron-mobility transistors （HEMTs） on SiC substrate were fabricated and character- ized. Several techniques, consisting of high electron density, 70 nm T-shaped gate, low ohmic contacts and a short drain-source distance, are integrated to gain high device performance. The fabricated InA1N/GaN HEMTs exhibit a maximum drain saturation current density of 1.65 A/ram at Vgs = 1 V and a maximum peak transconductance of 382 mS/rnm. In addition, a unity current gain cut-off frequency （fT） of 162 GHz and a maximum oscillation frequency （fmax） of 176 GHz are achieved on the devices with the 70 nm gate length.展开更多
InAs-based interband cascade lasers（ICLs） with InAs plasmon waveguides or InAs/AlSb superlattice（SL） waveguides were demonstrated at emission wavelengths below 4.1 μm. The threshold current densities of the laser...InAs-based interband cascade lasers（ICLs） with InAs plasmon waveguides or InAs/AlSb superlattice（SL） waveguides were demonstrated at emission wavelengths below 4.1 μm. The threshold current densities of the lasers with SL waveguides were 37 A/cm;at 77 K in continuous wave mode. The operation temperature of these lasers reached room temperature in pulsed mode. Compared with the thick InAs n++ plasmon cladding layer, the InAs/AlSb superlattice cladding layers have greater advantages for ICLs with wavelengths less than 4 μm even in InAs based ICLs because in the short-wavelength region they have a higher confinement factor than InAs plasmon waveguides.展开更多
We report an enhancement-mode InA1N/GaN HEMT using a fluorine plasma treatment. The threshold voltage was measured to be ＋0.86 V by linear extrapolation from the transfer characteristics. The transconductance is 0 mS...We report an enhancement-mode InA1N/GaN HEMT using a fluorine plasma treatment. The threshold voltage was measured to be ＋0.86 V by linear extrapolation from the transfer characteristics. The transconductance is 0 mS/mm at Vc, s = 0 V and VDS = 5 V, which shows a truly normal-offstate. The gate leakage current density of the enhancement-mode device shows two orders of magnitude lower than that of the depletion-mode device. The transfer characteristics of the E-mode InA1N/GaN HEMT at room temperature and high temperature are reported. The current gain cut-off frequency （fT） and the maximum oscillation frequency （fmax） of the enhancement-mode device with a gate length of 0.3 #m were 29.4 GHz and 37.6 GHz respectively, which is comparable with the depletion-mode device. A classical 16 elements small-signal model was deduced to describe the parasitic and the intrinsic parameters of the device.展开更多
We report high performance InA1N/GaN HEMTs grown on sapphire substrates. The lattice-matched InA1N/GaN HEMT sample showed a high 2DEG mobility of 1210 cmZ/（V.s） under a sheet density of 2.6 × 10^13 cm^-2. Large...We report high performance InA1N/GaN HEMTs grown on sapphire substrates. The lattice-matched InA1N/GaN HEMT sample showed a high 2DEG mobility of 1210 cmZ/（V.s） under a sheet density of 2.6 × 10^13 cm^-2. Large signal load-pull measurements for a （2 × 100 μm） x 0.25 μm device have been conducted with a drain voltage of 24 V at 10 GHz. The presented results confirm the high performances reachable by InAIN- based technology with an output power density of 4.69 W/ram, a linear gain of 11.8 dB and a peak power-added efficiency of 48%. This is the first report of high performance InA1N/GaN HEMTs in China's Mainland.展开更多
InA1N/GaN high-electron mobility transistors （HEMTs） with a gate length of 100 nm and oxygen plasma treatment were fabricated. A Si/Ti/A1/Ni/Au ohmic contact was also used to reduce the contact resistance. DC and RF...InA1N/GaN high-electron mobility transistors （HEMTs） with a gate length of 100 nm and oxygen plasma treatment were fabricated. A Si/Ti/A1/Ni/Au ohmic contact was also used to reduce the contact resistance. DC and RF characteristics of the devices were measured. The fabricated devices show a maximum drain current density of 2.18 A/mm at VGs = 2 V, a low on-resistance （Ron） of 1.49 x2.mm and low gate leakage current. An excellent frequency response was also obtained. The current cut-off frequency （fT） is 81 GHz and the maximum oscillation frequency is 138 GHz, respectively.展开更多
The etching and passivation processes of very long wavelength infrared(VLWIR)detector based on the InAs/GaSb/AlSb type-II superlattice have been studied.By studying the effect of each component in the citric acid solu...The etching and passivation processes of very long wavelength infrared(VLWIR)detector based on the InAs/GaSb/AlSb type-II superlattice have been studied.By studying the effect of each component in the citric acid solution(citric acid,phosphoric acid,hydrogen peroxide,deionized water),the best solution ratio is obtained.After comparing different passivation materials such as sulfide+SiO_(2),Al_(2)O_(3),Si_(3)N_(4) and SU8,it is found that SU8 passivation can reduce the dark current of the device to a greater degree.Combining this wet etching and SU8 passivation,the of VLWIR detector with a mesa diameter of 500μm is about 3.6Ω·cm^(2) at 77 K.展开更多
An 88 nm gate-length In0.53Ga0.47As/In0.52Alo.48As InP-based high electron mobility transistor （HEMT） was successfully fabricated with a gate width of 2× 50 μm and source-drain space of 2.4μm. The T-gate was ...An 88 nm gate-length In0.53Ga0.47As/In0.52Alo.48As InP-based high electron mobility transistor （HEMT） was successfully fabricated with a gate width of 2× 50 μm and source-drain space of 2.4μm. The T-gate was defined by electron beam lithography in a trilayer of PMMA/A1/UVIII. The exposure dose and the development time were optimized, and followed by an appropriate residual resist removal process. These devices also demonstrated excellent DC and RF characteristics： the extrinsic maximum transconductance, the full channel cur- rent, the threshold voltage, the current gain cutoff frequency and the maximum oscillation frequency of the HEMTs were 765 mS/mm, 591 mA/mm, -0.5 V, 150 GHz and 201 GHz, respectively. The HEMTs are promising for use in millimeter-wave integrated circuits.展开更多
基金Advanced Research Foundation of China(914xxx803-051xxx111)National Defense Advanced Research project(315xxxxx301)National Defense Innovation Program(48xx4).
基金Project supported by the Advanced Research Foundation of China(Grant No.914xxx803-051xxx111)the National Defense Advanced Research Project of China(Grant No.315xxxxx301)the National Defense Innovation Program of China(Grant No.48xx4)
文摘In this report, the effect of temperature on the In As/Al Sb heterojunction and high-electron-mobility transistors（HEMTs） with a gate length of 2 μm are discussed comprehensively. The results indicate that device performance is greatly improved at cryogenic temperatures. It is also observed that the device performance at 90 K is significantly improved with 27% lower gate leakage current, 12% higher maximum drain current, and 22.5% higher peak transconductance compared to 300 K. The temperature dependence of mobility and the two-dimensional electron gas concentration in the In As/Al Sb heterojunction for the temperature range 90 K-300 K is also investigated. The electron mobility at 90 K（42560 cm2/V·s）is 2.5 times higher than its value at 300 K（16911 cm^2/V·s） because of the weaker lattice vibration and the impurity ionization at cryogenic temperatures, which corresponds to a reduced scattering rate and higher mobility. We also noted that the two-dimensional electron gas concentration decreases slightly from 1.99 × 10^（12） cm^（-2） at 300 K to 1.7 × 10^（12） cm^（-2） at 90 K with a decrease in temperature due to the lower ionization at cryogenic temperature and the nearly constant ？Ec.
文摘One-band effective mass model is used to simulation of electron gas properties in quantum well. We calculate of dispersion curves for first three subbands. Calculation results of Fermi energy, effective mass at Fermi level as function of electron concentration are presented. The obtained results are good agreement with the experimental dates.
基金supported by the National Natural Science Foundation of China(No.61306113)
文摘lnA1N/GaN high-electron-mobility transistors （HEMTs） on SiC substrate were fabricated and character- ized. Several techniques, consisting of high electron density, 70 nm T-shaped gate, low ohmic contacts and a short drain-source distance, are integrated to gain high device performance. The fabricated InA1N/GaN HEMTs exhibit a maximum drain saturation current density of 1.65 A/ram at Vgs = 1 V and a maximum peak transconductance of 382 mS/rnm. In addition, a unity current gain cut-off frequency （fT） of 162 GHz and a maximum oscillation frequency （fmax） of 176 GHz are achieved on the devices with the 70 nm gate length.
基金Project supported by the National Natural Science Foundation of China(Nos.61790583,61774150,61774151)the National Basic Research Program of China(No.2014CB643903)
文摘InAs-based interband cascade lasers（ICLs） with InAs plasmon waveguides or InAs/AlSb superlattice（SL） waveguides were demonstrated at emission wavelengths below 4.1 μm. The threshold current densities of the lasers with SL waveguides were 37 A/cm;at 77 K in continuous wave mode. The operation temperature of these lasers reached room temperature in pulsed mode. Compared with the thick InAs n++ plasmon cladding layer, the InAs/AlSb superlattice cladding layers have greater advantages for ICLs with wavelengths less than 4 μm even in InAs based ICLs because in the short-wavelength region they have a higher confinement factor than InAs plasmon waveguides.
文摘We report an enhancement-mode InA1N/GaN HEMT using a fluorine plasma treatment. The threshold voltage was measured to be ＋0.86 V by linear extrapolation from the transfer characteristics. The transconductance is 0 mS/mm at Vc, s = 0 V and VDS = 5 V, which shows a truly normal-offstate. The gate leakage current density of the enhancement-mode device shows two orders of magnitude lower than that of the depletion-mode device. The transfer characteristics of the E-mode InA1N/GaN HEMT at room temperature and high temperature are reported. The current gain cut-off frequency （fT） and the maximum oscillation frequency （fmax） of the enhancement-mode device with a gate length of 0.3 #m were 29.4 GHz and 37.6 GHz respectively, which is comparable with the depletion-mode device. A classical 16 elements small-signal model was deduced to describe the parasitic and the intrinsic parameters of the device.
基金Project supported by the National Natural Science Foundation of China(Nos.60890192,60876009).
文摘We report high performance InA1N/GaN HEMTs grown on sapphire substrates. The lattice-matched InA1N/GaN HEMT sample showed a high 2DEG mobility of 1210 cmZ/（V.s） under a sheet density of 2.6 × 10^13 cm^-2. Large signal load-pull measurements for a （2 × 100 μm） x 0.25 μm device have been conducted with a drain voltage of 24 V at 10 GHz. The presented results confirm the high performances reachable by InAIN- based technology with an output power density of 4.69 W/ram, a linear gain of 11.8 dB and a peak power-added efficiency of 48%. This is the first report of high performance InA1N/GaN HEMTs in China's Mainland.
基金supported by the National Natural Science Foundation of China(No.61306113)
文摘InA1N/GaN high-electron mobility transistors （HEMTs） with a gate length of 100 nm and oxygen plasma treatment were fabricated. A Si/Ti/A1/Ni/Au ohmic contact was also used to reduce the contact resistance. DC and RF characteristics of the devices were measured. The fabricated devices show a maximum drain current density of 2.18 A/mm at VGs = 2 V, a low on-resistance （Ron） of 1.49 x2.mm and low gate leakage current. An excellent frequency response was also obtained. The current cut-off frequency （fT） is 81 GHz and the maximum oscillation frequency is 138 GHz, respectively.
基金supported by the National Basic Research Program of China(Grant Nos.2018YFA0209102 and 2019YFA070104)the National Natural Science Foundation of China(Grant Nos.61790581 and 61274013)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB22)。
文摘The etching and passivation processes of very long wavelength infrared(VLWIR)detector based on the InAs/GaSb/AlSb type-II superlattice have been studied.By studying the effect of each component in the citric acid solution(citric acid,phosphoric acid,hydrogen peroxide,deionized water),the best solution ratio is obtained.After comparing different passivation materials such as sulfide+SiO_(2),Al_(2)O_(3),Si_(3)N_(4) and SU8,it is found that SU8 passivation can reduce the dark current of the device to a greater degree.Combining this wet etching and SU8 passivation,the of VLWIR detector with a mesa diameter of 500μm is about 3.6Ω·cm^(2) at 77 K.
文摘An 88 nm gate-length In0.53Ga0.47As/In0.52Alo.48As InP-based high electron mobility transistor （HEMT） was successfully fabricated with a gate width of 2× 50 μm and source-drain space of 2.4μm. The T-gate was defined by electron beam lithography in a trilayer of PMMA/A1/UVIII. The exposure dose and the development time were optimized, and followed by an appropriate residual resist removal process. These devices also demonstrated excellent DC and RF characteristics： the extrinsic maximum transconductance, the full channel cur- rent, the threshold voltage, the current gain cutoff frequency and the maximum oscillation frequency of the HEMTs were 765 mS/mm, 591 mA/mm, -0.5 V, 150 GHz and 201 GHz, respectively. The HEMTs are promising for use in millimeter-wave integrated circuits.
