采用金属Ni作为掩膜,Cl2/BCl3作为刻蚀气体,利用感应耦合等离子体刻蚀(ICP)技术对Ga As HEMT背孔工艺进行研究。本文详细研究了ICP功率、反应室压强、Cl2/BCl3流量比以及RF功率对刻蚀速率、刻蚀形貌以及"长草"效应的影响。实...采用金属Ni作为掩膜,Cl2/BCl3作为刻蚀气体,利用感应耦合等离子体刻蚀(ICP)技术对Ga As HEMT背孔工艺进行研究。本文详细研究了ICP功率、反应室压强、Cl2/BCl3流量比以及RF功率对刻蚀速率、刻蚀形貌以及"长草"效应的影响。实验结果表明:刻蚀速率随ICP功率、Cl2/BCl3流量、RF功率的增加而增加,但随反应室压强的增加,刻蚀速率先增加后降低;相同RF功率条件下,背孔陡直性受ICP功率、反应室压强以及刻蚀气体流量比的影响十分明显;而RF功率则对背孔"长草"效应有较大影响。通过优化刻蚀条件,在ICP功率为500 W,反应室压强为0.4 Pa,Cl2/BCl3流量为20/5 m L/min,RF功率为120 W的刻蚀条件下,刻蚀背孔陡直性好,侧壁平滑,底部平整,刻蚀速率达到3μm/min。展开更多
In0.4Ga0.6As channel metal-oxide-semiconductor field-effect transistors （MOSFETs） with and without an Si-doped In0.49Ga0.51P barrier layer grown on semi-insulating GaAs substrates have been investigated for the firs...In0.4Ga0.6As channel metal-oxide-semiconductor field-effect transistors （MOSFETs） with and without an Si-doped In0.49Ga0.51P barrier layer grown on semi-insulating GaAs substrates have been investigated for the first time. Compared with the In0.4Ga0.6As MOSFETs without an In0.49Ga0.51P barrier layer, In0.4Ga0.6As MOSFETs with an In0.49Ga0.51P barrier layer show higher drive current, higher transconductance, lower gate leakage current, lower subthreshold swing, and higher effective channel mobility. These In0.4Ga0.6As MOSFETs （gate length 2 μm） with an In0.49Ga0.51P barrier layer exhibit a high drive current of 117 mA/mm, a high transconductance of 71.9 mS/mm, and a maximum effective channel mobility of 1266 cm2/（V·s）.展开更多
Positive bias temperature instability stress induced interface trap density in a buried InGaAs channel metaloxide-semiconductor field-effect transistor with a InCaP barrier layer and Al2O3 dielectric is investigated. ...Positive bias temperature instability stress induced interface trap density in a buried InGaAs channel metaloxide-semiconductor field-effect transistor with a InCaP barrier layer and Al2O3 dielectric is investigated. Well behaved split C-V characteristics with small capacitance frequency dispersion are confirmed after the insertion of the InCaP barrier layer. The direct-current Id-Vg measurements show both degradations of positive gate voltage shift and sub-threshold swing in the sub-threshold region, and degradation of positive △Vg in the oncurrent region. The Id-Vg degradation during the positive bias temperature instability tests is mainly contributed by the generation of near interface acceptor traps under stress. Specifically, the stress induced aeceptor traps contain both permanent and recoverable traps. Compared with surface channel InCaAs devices, stress induced recoverable donor traps are negligible in the buried channel ones.展开更多
To achieve a high-quality high-κ/Ge interfaces for high hole mobility Ge p-MOSFET applications, a simple chemical cleaning and surface passivation scheme is introduced, and Ge p-MOSFETs with effective channel hole mo...To achieve a high-quality high-κ/Ge interfaces for high hole mobility Ge p-MOSFET applications, a simple chemical cleaning and surface passivation scheme is introduced, and Ge p-MOSFETs with effective channel hole mobility up to 665 cm2/V.s are demonstrated on a Ge （111） substrate. Moreover, a physical model is proposed to explain the dipole layer formation at the metal-oxide-semiconductor （MOS） interface by analyzing the electrical characteristics of HCl- and （NH4）2S-passivated samples.展开更多
Type-II GaAsSb/InP DHBTs with selectively-etched InGaAsP ledge structures are fabricated and characterized for the first time. The novel InGaAsP/GaAsSb/InP DHBTs with a 20nm lattice-matched GaAsSb base and a 75 nm InP...Type-II GaAsSb/InP DHBTs with selectively-etched InGaAsP ledge structures are fabricated and characterized for the first time. The novel InGaAsP/GaAsSb/InP DHBTs with a 20nm lattice-matched GaAsSb base and a 75 nm InP collector have a dc current gain improvement by a factor of 2 and a cutoff frequency fT of 190 GHz. The InGaAsP ledge design provides a simple but effective approach to suppress the extrinsic base surface recombination and enable GaAsSb/InP DHBTs to further increase the operating frequencies and integration levels for millimeter wave applications.展开更多
A high microwave performance enhancement-mode(E-mode)In_(0.4)Ga_(0.6)As channel metal-oxide-semiconductor field-effect transistor(MOSFET)with a Si-doped In_(0.49)Ga0.51P interfacial layer is fabricated.A 0.8-μm-gate-...A high microwave performance enhancement-mode(E-mode)In_(0.4)Ga_(0.6)As channel metal-oxide-semiconductor field-effect transistor(MOSFET)with a Si-doped In_(0.49)Ga0.51P interfacial layer is fabricated.A 0.8-μm-gate-length In_(0.4)Ga_(0.6)As MOSFET with a 5-nm Al_(2)O_(3) dielectric layer provides a current gain cutoff frequency of 16.7 GHz and a maximum oscillation frequency of 52 GHz.A semi-empirical small-signal-parameter extraction technique accounting for the low frequency anomaly of this MOSFET device is described,which is based on on-wafer S-parameter measurements.Excellent agreement between measured and simulated scattering parameters as well as the physically realistic circuit elements demonstrates the validity of this approach.展开更多
We demonstrate a high performance implant-free n-type In_(0.7)Ga_(0.3)As channel MOSFET with a 4-nm InP barrier layer fabricated on a semi-insulating substrate employing a 10-nm Al_(2)O_(3) as gate dielectric.The maxi...We demonstrate a high performance implant-free n-type In_(0.7)Ga_(0.3)As channel MOSFET with a 4-nm InP barrier layer fabricated on a semi-insulating substrate employing a 10-nm Al_(2)O_(3) as gate dielectric.The maximum effective channel mobility is 1862 cm^(2)/V·s extracted by the split C–V method.Devices with 0.8μm gate length exhibit a peak extrinsic transconductance of 85 mS/mm and a drive current of more than 200 mA/mm.A short-circuit current gain cutoff frequency f_(T) of 24.5 GHz and a maximum oscillation frequency f_(max) of 54 GHz are achieved for the 0.8μm gate-length device.The research is helpful to obtain higher performance In_(0.7)Ga_(0.3)As MOSFETs for radio-frequency applications.展开更多
GaSb is an attractive candidate for future high-performance Ⅲ-Ⅴ p-channel metal-oxide-semiconductor-field-effect-transistors(pMOSFETs)because of its high hole mobility.The effect of HCl based-chemical cleaning on re...GaSb is an attractive candidate for future high-performance Ⅲ-Ⅴ p-channel metal-oxide-semiconductor-field-effect-transistors(pMOSFETs)because of its high hole mobility.The effect of HCl based-chemical cleaning on removing the non-self limiting and instable native oxide layer of GaSb to obtain a clean and smooth surface has been studied.It is observed that the rms roughness of a GaSb surface is significantly reduced from 2.731 nm to 0.693 nm by using HCl:H_(2)O(1:3)solution.The Ni/Pt/Au ohmic contact exhibits an optimal specific contact resistivity of about 6.89×10^(-7)Ω·cm^(2) with a 60 s rapid thermal anneal(RTA)at 250℃.Based on the chemical cleaning and ohmic contact experimental results,inversion-channel enhancement GaSb pMOSFETs are demonstrated.For a 6μm gate length GaSb pMOSFET,a maximum drain current of about 4.0 mA/mm,a drain current on-off(ION/IOFF)ratio of>10^(3),and a subthreshold swing of~250 mV/decade are achieved.Combined with the split C-V method,a peak hole mobility of about 160 cm^(2)/V·s is obtained for a 24μm gate length GaSb pMOSFET.展开更多
Heterogeneous integration of crystalline Ge layers on cleaned and H-terminated Si(111)substrates are demonstrated by employing a combination of e-beam evaporation and solid phase epitaxy techniques.High-quality single...Heterogeneous integration of crystalline Ge layers on cleaned and H-terminated Si(111)substrates are demonstrated by employing a combination of e-beam evaporation and solid phase epitaxy techniques.High-quality single crystalline Ge(111)layers on Si(111)substrates with a smooth Ge surface and an abrupt interface between Ge and Si are obtained.An XRD rocking curve scan of the Ge(111)diffraction peak shovs a FWHM of only 260 arcsec for a 50-nm-thick Ge layer annealed at 600℃with a ramp-up rate of 20℃/s and a holding time of 1 min.The AFM images exhibit that the rms surface roughness of all the crystalline Ge layers are less than 2.1 nm.展开更多
Surface treatment for Ge substrates using hydrogen chlorine cleaning and chemical passivation are investigated on AuTi/Al2O3/Ge metal-oxide-semiconductor capacitors.After hydrogen chlorine cleaning,a smooth Ge surface...Surface treatment for Ge substrates using hydrogen chlorine cleaning and chemical passivation are investigated on AuTi/Al2O3/Ge metal-oxide-semiconductor capacitors.After hydrogen chlorine cleaning,a smooth Ge surface almost free from native oxide is demonstrated by atomic force microscopy and x-ray photoelectron spectroscopy observations.Passivation using a hydrogen chlorine solution is found to form a chlorine-terminated surface,while aqueous ammonium sulfide pretreatment results in a surface terminated by Ge-S bonding.Compared with chlorine-passivated samples,the sulfur-passivated ones show less frequency dispersion and better thermal stability based on capacitance-voltage characterizations.The samples with HCl pre-cleaning and (NH4 )2S passivation show less frequency dispersion than the HF pre-cleaning and (NH4)2S passivated ones.The surface treatment process using hydrogen chlorine cleaning followed by aqueous ammonium sulfide passivation demonstrates a promising way to improve gate dielectric/Ge interface quality.展开更多
The solid phase reactions of Ni with GaAs substrates are investigated.The experimental results reveal that the Ni-GaAs solid phase reaction forms a ternary phase of Ni2GaAs when annealing temperatures are in the range...The solid phase reactions of Ni with GaAs substrates are investigated.The experimental results reveal that the Ni-GaAs solid phase reaction forms a ternary phase of Ni2GaAs when annealing temperatures are in the range 250 300℃.As the annealing temperature increases to 400℃,the Ni2GaAs phase starts to decompose due to NiAs phase precipitation.Ni-GaAs alloys processed at 400℃ with a 3min annealing time demonstrate a sheet resistance of 30Ω/square after unreacted Ni removal in hot diluted-HCl solutions.Therefore,Ni-GaAs alloys formed by solid phase reaction could be promising metallic source/drain structures with significant low series resistance for high mobility Ⅲ-Ⅴ metal-oxide-semiconductor field effect transistor (MOSFET) applications.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
We investigate a passivation scheme using hydrogenated amorphous silicon suboxide （a-SiOx ：H） film for industrial solar cell application. The a-SiOx ：H films were deposited using plasma-enhanced chemical vapor dep...We investigate a passivation scheme using hydrogenated amorphous silicon suboxide （a-SiOx ：H） film for industrial solar cell application. The a-SiOx ：H films were deposited using plasma-enhanced chemical vapor deposition （PECVD） by decomposing nitrous oxide, helium and silane at a substrate temperature of around 250 ℃. An extensive study has been carried out on the effect of thermal annealing on carrier lifetime and surface recombination velocity, which affect the final output of the solar cell. Minority carrier lifetimes for the deposited a-SiOx ：H films without and with the thermal annealing on 4 Ω-cm p-type float-zone silicon wafers are 270 μs and 670μs, respectively, correlating to surface recombination velocities of 70 cm/s and 30 cm/s. Optical analysis has revealed a distinct decrease of blue light absorption in the a-SiOx ：H films compared to the commonly used intrinsic amorphous silicon passivation used in solar cells. This paper also reports that the low cost and high quality passivation fabrication sequences employed in this study are suitable for industrial processes.展开更多
The impact of various thicknesses of Al2O3 metal-insulator-metal （MIM） capacitors on direct current and radio frequency （RF） characteristics is investigated. For 20 nm Al2O3, the fabricated capacitor exhibits a hi...The impact of various thicknesses of Al2O3 metal-insulator-metal （MIM） capacitors on direct current and radio frequency （RF） characteristics is investigated. For 20 nm Al2O3, the fabricated capacitor exhibits a high capacitance density of 3850 pF/mm2 and acceptable voltage coefficients of capacitance of 681 ppm/V2 at 1 MHz. An outstanding VCC-a of 74 ppm/V2 at 1 MHz, resonance frequency of 8.2 GHz and Q factor of 41 at 2 GHz are obtained by 100 nm Al2O3 MIM capacitors. High-performance MIM capacitors using GaAs process and atomic layer deposition Al2O3 could be very promising candidates for GaAs RFIC applications.展开更多
An InP/InGaAs single heterojunction bipolar transistor（SHBT） with high maximum oscillation frequency （fmax） and high cutoff frequency（ft） is reported.Efforts have been made to maximize f（max） and ft simultaneo...An InP/InGaAs single heterojunction bipolar transistor（SHBT） with high maximum oscillation frequency （fmax） and high cutoff frequency（ft） is reported.Efforts have been made to maximize f（max） and ft simultaneously including optimizing the epitaxial structure,base-collector mesa over-etching and base surface preparation.The measured ft and fmax both reached 185 GHz with an emitter size of 1×20μm^2,which is the highest f_（max） for SHBTs in China's Mainland.The device is suitable for ultra-high speed digital circuits and low power analog applications.展开更多
文摘采用金属Ni作为掩膜,Cl2/BCl3作为刻蚀气体,利用感应耦合等离子体刻蚀(ICP)技术对Ga As HEMT背孔工艺进行研究。本文详细研究了ICP功率、反应室压强、Cl2/BCl3流量比以及RF功率对刻蚀速率、刻蚀形貌以及"长草"效应的影响。实验结果表明:刻蚀速率随ICP功率、Cl2/BCl3流量、RF功率的增加而增加,但随反应室压强的增加,刻蚀速率先增加后降低;相同RF功率条件下,背孔陡直性受ICP功率、反应室压强以及刻蚀气体流量比的影响十分明显;而RF功率则对背孔"长草"效应有较大影响。通过优化刻蚀条件,在ICP功率为500 W,反应室压强为0.4 Pa,Cl2/BCl3流量为20/5 m L/min,RF功率为120 W的刻蚀条件下,刻蚀背孔陡直性好,侧壁平滑,底部平整,刻蚀速率达到3μm/min。
基金the National Basic Research Program of China(Grant Nos.2011CBA00605 and 2010CB327501)the National Natural Science Foundation of China(Grant No.61106095)the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2011ZX02708-003)
文摘In0.4Ga0.6As channel metal-oxide-semiconductor field-effect transistors （MOSFETs） with and without an Si-doped In0.49Ga0.51P barrier layer grown on semi-insulating GaAs substrates have been investigated for the first time. Compared with the In0.4Ga0.6As MOSFETs without an In0.49Ga0.51P barrier layer, In0.4Ga0.6As MOSFETs with an In0.49Ga0.51P barrier layer show higher drive current, higher transconductance, lower gate leakage current, lower subthreshold swing, and higher effective channel mobility. These In0.4Ga0.6As MOSFETs （gate length 2 μm） with an In0.49Ga0.51P barrier layer exhibit a high drive current of 117 mA/mm, a high transconductance of 71.9 mS/mm, and a maximum effective channel mobility of 1266 cm2/（V·s）.
基金Supported by the National Science and Technology Major Project of China under Grant No 2011ZX02708-003the National Natural Science Foundation of China under Grant No 61504165the Opening Project of Key Laboratory of Microelectronics Devices and Integrated Technology of Institute of Microelectronics of Chinese Academy of Sciences
文摘Positive bias temperature instability stress induced interface trap density in a buried InGaAs channel metaloxide-semiconductor field-effect transistor with a InCaP barrier layer and Al2O3 dielectric is investigated. Well behaved split C-V characteristics with small capacitance frequency dispersion are confirmed after the insertion of the InCaP barrier layer. The direct-current Id-Vg measurements show both degradations of positive gate voltage shift and sub-threshold swing in the sub-threshold region, and degradation of positive △Vg in the oncurrent region. The Id-Vg degradation during the positive bias temperature instability tests is mainly contributed by the generation of near interface acceptor traps under stress. Specifically, the stress induced aeceptor traps contain both permanent and recoverable traps. Compared with surface channel InCaAs devices, stress induced recoverable donor traps are negligible in the buried channel ones.
基金Project supported by the National Basic Research Program of China (Grant Nos.2011CBA00605 and 2010CB327501)the National Natural Science Foundation of China (Grant No.61106095)the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No.2011ZX02708-003)
文摘To achieve a high-quality high-κ/Ge interfaces for high hole mobility Ge p-MOSFET applications, a simple chemical cleaning and surface passivation scheme is introduced, and Ge p-MOSFETs with effective channel hole mobility up to 665 cm2/V.s are demonstrated on a Ge （111） substrate. Moreover, a physical model is proposed to explain the dipole layer formation at the metal-oxide-semiconductor （MOS） interface by analyzing the electrical characteristics of HCl- and （NH4）2S-passivated samples.
文摘Type-II GaAsSb/InP DHBTs with selectively-etched InGaAsP ledge structures are fabricated and characterized for the first time. The novel InGaAsP/GaAsSb/InP DHBTs with a 20nm lattice-matched GaAsSb base and a 75 nm InP collector have a dc current gain improvement by a factor of 2 and a cutoff frequency fT of 190 GHz. The InGaAsP ledge design provides a simple but effective approach to suppress the extrinsic base surface recombination and enable GaAsSb/InP DHBTs to further increase the operating frequencies and integration levels for millimeter wave applications.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00605 and 2010CB327501the National Science&Technology Major Project under Grant No 2011ZX02708-003One Hundred Talents Program of Chinese Academy of Sciences,and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the Ministry of Education of China.
文摘A high microwave performance enhancement-mode(E-mode)In_(0.4)Ga_(0.6)As channel metal-oxide-semiconductor field-effect transistor(MOSFET)with a Si-doped In_(0.49)Ga0.51P interfacial layer is fabricated.A 0.8-μm-gate-length In_(0.4)Ga_(0.6)As MOSFET with a 5-nm Al_(2)O_(3) dielectric layer provides a current gain cutoff frequency of 16.7 GHz and a maximum oscillation frequency of 52 GHz.A semi-empirical small-signal-parameter extraction technique accounting for the low frequency anomaly of this MOSFET device is described,which is based on on-wafer S-parameter measurements.Excellent agreement between measured and simulated scattering parameters as well as the physically realistic circuit elements demonstrates the validity of this approach.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00605,2010CB327501the National Science&Technology Major Project under Grant No 2011ZX02708-003One Hundred Talents Program of Chinese Academy of Sciences,and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the Ministry of Education of China.
文摘We demonstrate a high performance implant-free n-type In_(0.7)Ga_(0.3)As channel MOSFET with a 4-nm InP barrier layer fabricated on a semi-insulating substrate employing a 10-nm Al_(2)O_(3) as gate dielectric.The maximum effective channel mobility is 1862 cm^(2)/V·s extracted by the split C–V method.Devices with 0.8μm gate length exhibit a peak extrinsic transconductance of 85 mS/mm and a drive current of more than 200 mA/mm.A short-circuit current gain cutoff frequency f_(T) of 24.5 GHz and a maximum oscillation frequency f_(max) of 54 GHz are achieved for the 0.8μm gate-length device.The research is helpful to obtain higher performance In_(0.7)Ga_(0.3)As MOSFETs for radio-frequency applications.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00605,2010CB327501the National Natural Science Foundation of China under Grant No 61106095+1 种基金the National Science&Technology Major Project of China under Grant No 2011ZX02708-003One Hundred Talents Program of Chinese Academy of Sciences,and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the Ministry of Education of China.
文摘GaSb is an attractive candidate for future high-performance Ⅲ-Ⅴ p-channel metal-oxide-semiconductor-field-effect-transistors(pMOSFETs)because of its high hole mobility.The effect of HCl based-chemical cleaning on removing the non-self limiting and instable native oxide layer of GaSb to obtain a clean and smooth surface has been studied.It is observed that the rms roughness of a GaSb surface is significantly reduced from 2.731 nm to 0.693 nm by using HCl:H_(2)O(1:3)solution.The Ni/Pt/Au ohmic contact exhibits an optimal specific contact resistivity of about 6.89×10^(-7)Ω·cm^(2) with a 60 s rapid thermal anneal(RTA)at 250℃.Based on the chemical cleaning and ohmic contact experimental results,inversion-channel enhancement GaSb pMOSFETs are demonstrated.For a 6μm gate length GaSb pMOSFET,a maximum drain current of about 4.0 mA/mm,a drain current on-off(ION/IOFF)ratio of>10^(3),and a subthreshold swing of~250 mV/decade are achieved.Combined with the split C-V method,a peak hole mobility of about 160 cm^(2)/V·s is obtained for a 24μm gate length GaSb pMOSFET.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CB309605 and 2010CB327501the National Science&Technology Major Project of China under Grant No 2011ZX02708-003.
文摘Heterogeneous integration of crystalline Ge layers on cleaned and H-terminated Si(111)substrates are demonstrated by employing a combination of e-beam evaporation and solid phase epitaxy techniques.High-quality single crystalline Ge(111)layers on Si(111)substrates with a smooth Ge surface and an abrupt interface between Ge and Si are obtained.An XRD rocking curve scan of the Ge(111)diffraction peak shovs a FWHM of only 260 arcsec for a 50-nm-thick Ge layer annealed at 600℃with a ramp-up rate of 20℃/s and a holding time of 1 min.The AFM images exhibit that the rms surface roughness of all the crystalline Ge layers are less than 2.1 nm.
基金Supported by the National Basic Research Program of China under Grant NoS 2011CBA00605 and 2010CB327501the National Science&Technology Major Project of China under Grant No 2011ZX02708-003,One Hundred Talents Program of Chinese Academy of Sciencesthe Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry.
文摘Surface treatment for Ge substrates using hydrogen chlorine cleaning and chemical passivation are investigated on AuTi/Al2O3/Ge metal-oxide-semiconductor capacitors.After hydrogen chlorine cleaning,a smooth Ge surface almost free from native oxide is demonstrated by atomic force microscopy and x-ray photoelectron spectroscopy observations.Passivation using a hydrogen chlorine solution is found to form a chlorine-terminated surface,while aqueous ammonium sulfide pretreatment results in a surface terminated by Ge-S bonding.Compared with chlorine-passivated samples,the sulfur-passivated ones show less frequency dispersion and better thermal stability based on capacitance-voltage characterizations.The samples with HCl pre-cleaning and (NH4 )2S passivation show less frequency dispersion than the HF pre-cleaning and (NH4)2S passivated ones.The surface treatment process using hydrogen chlorine cleaning followed by aqueous ammonium sulfide passivation demonstrates a promising way to improve gate dielectric/Ge interface quality.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00605 and 2010CB327501the National Science&Technology Major Project of China under Grant No 2011ZX02708-003+1 种基金One-Hundred Talent Program of Chinese Academy of Sciencesthe Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China.
文摘The solid phase reactions of Ni with GaAs substrates are investigated.The experimental results reveal that the Ni-GaAs solid phase reaction forms a ternary phase of Ni2GaAs when annealing temperatures are in the range 250 300℃.As the annealing temperature increases to 400℃,the Ni2GaAs phase starts to decompose due to NiAs phase precipitation.Ni-GaAs alloys processed at 400℃ with a 3min annealing time demonstrate a sheet resistance of 30Ω/square after unreacted Ni removal in hot diluted-HCl solutions.Therefore,Ni-GaAs alloys formed by solid phase reaction could be promising metallic source/drain structures with significant low series resistance for high mobility Ⅲ-Ⅴ metal-oxide-semiconductor field effect transistor (MOSFET) applications.
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.
文摘We investigate a passivation scheme using hydrogenated amorphous silicon suboxide （a-SiOx ：H） film for industrial solar cell application. The a-SiOx ：H films were deposited using plasma-enhanced chemical vapor deposition （PECVD） by decomposing nitrous oxide, helium and silane at a substrate temperature of around 250 ℃. An extensive study has been carried out on the effect of thermal annealing on carrier lifetime and surface recombination velocity, which affect the final output of the solar cell. Minority carrier lifetimes for the deposited a-SiOx ：H films without and with the thermal annealing on 4 Ω-cm p-type float-zone silicon wafers are 270 μs and 670μs, respectively, correlating to surface recombination velocities of 70 cm/s and 30 cm/s. Optical analysis has revealed a distinct decrease of blue light absorption in the a-SiOx ：H films compared to the commonly used intrinsic amorphous silicon passivation used in solar cells. This paper also reports that the low cost and high quality passivation fabrication sequences employed in this study are suitable for industrial processes.
基金Project 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The impact of various thicknesses of Al2O3 metal-insulator-metal （MIM） capacitors on direct current and radio frequency （RF） characteristics is investigated. For 20 nm Al2O3, the fabricated capacitor exhibits a high capacitance density of 3850 pF/mm2 and acceptable voltage coefficients of capacitance of 681 ppm/V2 at 1 MHz. An outstanding VCC-a of 74 ppm/V2 at 1 MHz, resonance frequency of 8.2 GHz and Q factor of 41 at 2 GHz are obtained by 100 nm Al2O3 MIM capacitors. High-performance MIM capacitors using GaAs process and atomic layer deposition Al2O3 could be very promising candidates for GaAs RFIC applications.
基金supported by the State Key Development Program for Basic Research of China(No.2010CB327502)the National Natural Science Foundation of China(No.60976064)
文摘An InP/InGaAs single heterojunction bipolar transistor（SHBT） with high maximum oscillation frequency （fmax） and high cutoff frequency（ft） is reported.Efforts have been made to maximize f（max） and ft simultaneously including optimizing the epitaxial structure,base-collector mesa over-etching and base surface preparation.The measured ft and fmax both reached 185 GHz with an emitter size of 1×20μm^2,which is the highest f_（max） for SHBTs in China's Mainland.The device is suitable for ultra-high speed digital circuits and low power analog applications.
