The kink effect in current-voltage (IV) characteristic s seriously deteriorates the performance of a GaN-based HEMT. Based on a series of direct current (DC) IV measurements in a GaN-based HEMT with an AlGaN back ...The kink effect in current-voltage (IV) characteristic s seriously deteriorates the performance of a GaN-based HEMT. Based on a series of direct current (DC) IV measurements in a GaN-based HEMT with an AlGaN back barrier, a possible mechanism with electron-trapping and detrapping processes is proposed. Kink-related deep levels are activated by a high drain source voltage (Vds) and located in a GaN channel layer. Both electron trapping and detrapping processes are accomplished with the help of hot electrons from the channel by impact ionization. Moreover, the mechanism is verified by two other DC IV measurements and a model with an expression of the kink current.展开更多
In this paper, the effect of alumina thickness on Al2O3/InP interface with post deposition annealing (PDA) in the oxygen ambient is studied. Atomic layer deposited (ALD) Al2O3 films with four different thickness v...In this paper, the effect of alumina thickness on Al2O3/InP interface with post deposition annealing (PDA) in the oxygen ambient is studied. Atomic layer deposited (ALD) Al2O3 films with four different thickness values (5 nm, 7 nm, 9 nm, 11 rim) are deposited on InP substrates. The capacitance-voltage (C-V) measurement shows a negative correlation between the alumina thickness and the frequency dispersion. The X-ray photoelectronspectroscopy (XPS) data present significant growth of indium-phosphorus oxide near the Al2O3/InP interface, which indicates serious oxidation of InP during the oxygen annealing. The hysteresis curve shows an optimum thickness of 7 nm after PDA in an oxygen ambient at 500 ℃ for 10 min. It is demonstrated that both sides of the interface are impacted by oxygen during post deposition annealing. It is suggested that the final state of the interface is of reduced positively charged defects on Al2O3 side and oxidized InP, which degrades the interface.展开更多
A novel radio frequency (RF) switch device has been successfully fabricated using InGaAs metal- oxide-semiconductor field-effect transistor (MOSFET) technology. The device showed drain saturation currents of 250 m...A novel radio frequency (RF) switch device has been successfully fabricated using InGaAs metal- oxide-semiconductor field-effect transistor (MOSFET) technology. The device showed drain saturation currents of 250 mA/mm, a maximum transconductance of 370 mS/ram, a turn-on resistance of 0.72 mx2.mm2 and a drain current on-off (Ionloll) ratio of 1 x 106. The maximum handling power of on-state of 533 mW/mm and off-state of 3667 mW/mm is obtained. The proposed In0.4Ga0.6As MOSFET RF switch showed an insertion loss of less than 1.8 dB and an isolation of better than 20 dB in the frequency range from 0.1 to 7.5 GHz. The lowest insertion loss and the highest isolation can reach 0.27 dB and more than 68 dB respectively. This study demonstrates that the InGaAs MOSFET technology has a great potential for RF switch application.展开更多
基金Project supported by the Program for New Century Excellent Talents in University,China (Grant No.NCET-12-0915)
文摘The kink effect in current-voltage (IV) characteristic s seriously deteriorates the performance of a GaN-based HEMT. Based on a series of direct current (DC) IV measurements in a GaN-based HEMT with an AlGaN back barrier, a possible mechanism with electron-trapping and detrapping processes is proposed. Kink-related deep levels are activated by a high drain source voltage (Vds) and located in a GaN channel layer. Both electron trapping and detrapping processes are accomplished with the help of hot electrons from the channel by impact ionization. Moreover, the mechanism is verified by two other DC IV measurements and a model with an expression of the kink current.
基金supported by the National Natural Science Foundation of China(Grant No.61204006)the Fundamental Research Funds for the Central Universities,China(Grant No.K50511250002)the National Key Science and Technology Special Project,China(Grant No.2008ZX01002-002)
文摘In this paper, the effect of alumina thickness on Al2O3/InP interface with post deposition annealing (PDA) in the oxygen ambient is studied. Atomic layer deposited (ALD) Al2O3 films with four different thickness values (5 nm, 7 nm, 9 nm, 11 rim) are deposited on InP substrates. The capacitance-voltage (C-V) measurement shows a negative correlation between the alumina thickness and the frequency dispersion. The X-ray photoelectronspectroscopy (XPS) data present significant growth of indium-phosphorus oxide near the Al2O3/InP interface, which indicates serious oxidation of InP during the oxygen annealing. The hysteresis curve shows an optimum thickness of 7 nm after PDA in an oxygen ambient at 500 ℃ for 10 min. It is demonstrated that both sides of the interface are impacted by oxygen during post deposition annealing. It is suggested that the final state of the interface is of reduced positively charged defects on Al2O3 side and oxidized InP, which degrades the interface.
基金supported by the National Natural Science Foundation of China(Nos.61274077,61474031)the Guangxi Natural Science Foundation(No.2013GXNSFGA019003)+6 种基金the Guangxi Department of Education Project(No.201202ZD041)the Guilin City Technology Bureau(Nos.20120104-8,20130107-4)the China Postdoctoral Science Foundation Funded Project(Nos.2012M521127,2013T60566)the National Basic Research Program of China(Nos.2011CBA00605,2010CB327501)the Innovation Project of GUET Graduate Education(Nos.GDYCSZ201448,GDYCSZ201449)the State key Laboratory of Electronic Thin Films and Integrated Devices,UESTC(No.KFJJ201205)the Guilin City Science and Technology Development Project(Nos.20130107-4,20120104-8)
文摘A novel radio frequency (RF) switch device has been successfully fabricated using InGaAs metal- oxide-semiconductor field-effect transistor (MOSFET) technology. The device showed drain saturation currents of 250 mA/mm, a maximum transconductance of 370 mS/ram, a turn-on resistance of 0.72 mx2.mm2 and a drain current on-off (Ionloll) ratio of 1 x 106. The maximum handling power of on-state of 533 mW/mm and off-state of 3667 mW/mm is obtained. The proposed In0.4Ga0.6As MOSFET RF switch showed an insertion loss of less than 1.8 dB and an isolation of better than 20 dB in the frequency range from 0.1 to 7.5 GHz. The lowest insertion loss and the highest isolation can reach 0.27 dB and more than 68 dB respectively. This study demonstrates that the InGaAs MOSFET technology has a great potential for RF switch application.