The introduction of strain In_(x)Ga_(1-x)As channel with high In content increases the confinement of the two-dimensional electron gas(2DEG)and further improves the high-frequency performance of InGaAs/InAlAs/InP HEMT...The introduction of strain In_(x)Ga_(1-x)As channel with high In content increases the confinement of the two-dimensional electron gas(2DEG)and further improves the high-frequency performance of InGaAs/InAlAs/InP HEMTs.The effect of In_(x)Ga_(1-x)As channel with different In contents on electron irradiation tolerance of InP-based HEMT structures in terms of 2DEG mobility and density has been investigated.The experiment results show that,after the same high electron irradiation dose,the 2DEG mobility and density in InP-based HEMT structures with strain In_(x)Ga_(1-x)As(x>0.53)channel decrease more dramatically than that without strain In_(0.53)Ga_(0.47)As channel.Moreover,the degradation of 2DEG mobility and density becomes more severe as the increase of In content and strain in the In_(x)Ga_(1-x)As channel.The research results can provide some suggestions for the design of radiation-resistant InP-based HEMTs.展开更多
The T-gate stem height of In Al As/In Ga As In P-based high electron mobility transistor(HEMT) is increased from165 nm to 250 nm. The influences of increasing the gate stem height on the direct current(DC) and radio f...The T-gate stem height of In Al As/In Ga As In P-based high electron mobility transistor(HEMT) is increased from165 nm to 250 nm. The influences of increasing the gate stem height on the direct current(DC) and radio frequency(RF)performances of device are investigated. A 120-nm-long gate, 250-nm-high gate stem device exhibits a higher threshold voltage(Vth) of 60 m V than a 120-nm-long gate devices with a short gate stem, caused by more Pt distributions on the gate foot edges of the high Ti/Pt/Au gate. The Pt distribution in Schottky contact metal is found to increase with the gate stem height or the gate length increasing, and thus enhancing the Schottky barrier height and expanding the gate length,which can be due to the increased internal tensile stress of Pt. The more Pt distributions for the high gate stem device also lead to more obvious Pt sinking, which reduces the distance between the gate and the In Ga As channel so that the transconductance(gm) of the high gate stem device is 70 m S/mm larger than that of the short stem device. As for the RF performances,the gate extrinsic parasitic capacitance decreases and the intrinsic transconductance increases after the gate stem height has been increased, so the RF performances of device are obviously improved. The high gate stem device yields a maximum ft of 270 GHz and fmax of 460 GHz, while the short gate stem device has a maximum ft of 240 GHz and the fmax of 370 GHz.展开更多
InP-based high electron mobility transistors（HEMTs） will be affected by protons from different directions in space radiation applications. The proton irradiation effects on InAlAs/InGaAs hetero-junction structures o...InP-based high electron mobility transistors（HEMTs） will be affected by protons from different directions in space radiation applications. The proton irradiation effects on InAlAs/InGaAs hetero-junction structures of InP-based HEMTs are studied at incident angles ranging from 0 to 89.9° by SRIM software. With the increase of proton incident angle, the change trend of induced vacancy defects in the InAlAs/InGaAs hetero-junction region is consistent with the vacancy energy loss trend of incident protons. Namely, they both have shown an initial increase, followed by a decrease after incident angle has reached 30°. Besides, the average range and ultimate stopping positions of incident protons shift gradually from buffer layer to hetero-junction region, and then go up to gate metal. Finally, the electrical characteristics of InP-based HEMTs are investigated after proton irradiation at different incident angles by Sentaurus-TCAD. The induced vacancy defects are considered self-consistently through solving Poisson＇s and current continuity equations. Consequently, the extrinsic transconductance, pinch-off voltage and channel current demonstrate the most serious degradation at the incident angle of 30？, which can be accounted for the most severe carrier sheet density reduction under this condition.展开更多
An anti-radiation structure of In P-based high electron mobility transistor(HEMT) has been proposed and optimized with double Si-doped planes. The additional Si-doped plane under channel layer has made a huge promotio...An anti-radiation structure of In P-based high electron mobility transistor(HEMT) has been proposed and optimized with double Si-doped planes. The additional Si-doped plane under channel layer has made a huge promotion in channel current, transconductance, current gain cut-off frequency, and maximum oscillation frequency of In P-based HEMTs. Moreover, direct current(DC) and radio frequency(RF) characteristic properties and their reduction rates have been compared in detail between single Si-doped and double Si-doped structures after 75-keV proton irradiation with dose of 5× 10^(11) cm^(-2),1× 10^(12) cm^(-2), and 5× 10^(12) cm^(-2). DC and RF characteristics for both structures are observed to decrease gradually as irradiation dose rises, which particularly show a drastic drop at dose of 5× 10^(12) cm^(-2). Besides, characteristic degradation degree of the double Si-doped structure is significantly lower than that of the single Si-doped structure, especially at large proton irradiation dose. The enhancement of proton radiation tolerance by the insertion of another Si-doped plane could be accounted for the tremendously increased native carriers, which are bound to weaken substantially the carrier removal effect by irradiation-induced defects.展开更多
A double-recessed offset gate process technology for In P-based high electron mobility transistors(HEMTs)has been developed in this paper.Single-recessed and double-recessed HEMTs with different gate offsets have been...A double-recessed offset gate process technology for In P-based high electron mobility transistors(HEMTs)has been developed in this paper.Single-recessed and double-recessed HEMTs with different gate offsets have been fabricated and characterized.Compared with single-recessed devices,the maximum drain-source current(I_(D,max))and maximum extrinsic transconductance(g_(m,max))of double-recessed devices decreased due to the increase in series resistances.However,in terms of RF performance,double-recessed HEMTs achieved higher maximum oscillation frequency(f_(MAX))by reducing drain output conductance(g_(m,max))and drain to gate capacitance(C_gd).In addition,further improvement of fMAXwas observed by adjusting the gate offset of double-recessed devices.This can be explained by suppressing the ratio of C_(gd)to source to gate capacitance(C_gd)by extending drain-side recess length(Lrd).Compared with the single-recessed HEMTs,the f;of double-recessed offset gate HEMTs was increased by about 20%.展开更多
A set of 100-nm gate-length In P-based high electron mobility transistors(HEMTs)were designed and fabricated with different gate offsets in gate recess.A novel technology was proposed for independent definition of gat...A set of 100-nm gate-length In P-based high electron mobility transistors(HEMTs)were designed and fabricated with different gate offsets in gate recess.A novel technology was proposed for independent definition of gate recess and T-shaped gate by electron beam lithography.DC and RF measurement was conducted.With the gate offset varying from drain side to source side,the maximum drain current(I_(ds,max))and transconductance(g_(m,max))increased.In the meantime,fTdecreased while f;increased,and the highest fmax of 1096 GHz was obtained.It can be explained by the increase of gate-source capacitance and the decrease of gate-drain capacitance and source resistance.Output conductance was also suppressed by gate offset toward source side.This provides simple and flexible device parameter selection for HEMTs of different usages.展开更多
120 nm gate-length In_（0.7）Ga_（0.3）As/In_（0.52）Al_（0.48） As InP-based high electron mobility transitions（HEMTs） are fabricated by a new T-shaped gate electron beam lithograph（EBL） technology,which is achie...120 nm gate-length In_（0.7）Ga_（0.3）As/In_（0.52）Al_（0.48） As InP-based high electron mobility transitions（HEMTs） are fabricated by a new T-shaped gate electron beam lithograph（EBL） technology,which is achieved by the use of a PMMA/PMGI/ZEP520/PMGI four-layer photoresistor stack.These devices also demonstrate excellent DC and RF characteristics：the transconductance,maximum saturation drain-to-source current,threshold voltage,maximum current gain frequency,and maximum power-gain cutoff frequency of InGaAs/InAlAs HEMTs is 520 mS/mm,446 mA/mm, -1.0 V,141 GHz and 120 GHz,respectively.The material structure and all the device fabrication technology in this work were developed by our group.展开更多
A new PMMA/PMGI/ZEP520/PMGI four-layer resistor electron beam lithography technology is successfully developed and used to fabricate a 120 nm gate-length lattice-matched In_（0.53）Ga_（0.47）As/In_（0.52）Al_（0.48）...A new PMMA/PMGI/ZEP520/PMGI four-layer resistor electron beam lithography technology is successfully developed and used to fabricate a 120 nm gate-length lattice-matched In_（0.53）Ga_（0.47）As/In_（0.52）Al_（0.48） As InP-based HEMT,of which the material structure is successfully designed and optimized by our group.A 980 nm ultra-wide T-gate head,which is nearly as wide as 8 times the gatefoot（120 nm）,is successfully obtained,and the excellent T-gate profile greatly reduces the parasitic resistance and capacitance effect and effectively enhances the RF performances. These fabricated devices demonstrate excellent DC and RF performances such as a maximum current gain frequency of 190 GHz and a unilateral power-gain gain frequency of 146 GHz.展开更多
基金National Natural Science Foundation of China(11705277)Science and Technology Research Project of Hubei Provincial Department of Education(Q20222607)Graduate Quality Engineering Support Project of Hubei University of Arts and Science(YZ3202405)。
文摘The introduction of strain In_(x)Ga_(1-x)As channel with high In content increases the confinement of the two-dimensional electron gas(2DEG)and further improves the high-frequency performance of InGaAs/InAlAs/InP HEMTs.The effect of In_(x)Ga_(1-x)As channel with different In contents on electron irradiation tolerance of InP-based HEMT structures in terms of 2DEG mobility and density has been investigated.The experiment results show that,after the same high electron irradiation dose,the 2DEG mobility and density in InP-based HEMT structures with strain In_(x)Ga_(1-x)As(x>0.53)channel decrease more dramatically than that without strain In_(0.53)Ga_(0.47)As channel.Moreover,the degradation of 2DEG mobility and density becomes more severe as the increase of In content and strain in the In_(x)Ga_(1-x)As channel.The research results can provide some suggestions for the design of radiation-resistant InP-based HEMTs.
基金Project supported by the National Natural Science Foundation of China(Grant No.61434006)。
文摘The T-gate stem height of In Al As/In Ga As In P-based high electron mobility transistor(HEMT) is increased from165 nm to 250 nm. The influences of increasing the gate stem height on the direct current(DC) and radio frequency(RF)performances of device are investigated. A 120-nm-long gate, 250-nm-high gate stem device exhibits a higher threshold voltage(Vth) of 60 m V than a 120-nm-long gate devices with a short gate stem, caused by more Pt distributions on the gate foot edges of the high Ti/Pt/Au gate. The Pt distribution in Schottky contact metal is found to increase with the gate stem height or the gate length increasing, and thus enhancing the Schottky barrier height and expanding the gate length,which can be due to the increased internal tensile stress of Pt. The more Pt distributions for the high gate stem device also lead to more obvious Pt sinking, which reduces the distance between the gate and the In Ga As channel so that the transconductance(gm) of the high gate stem device is 70 m S/mm larger than that of the short stem device. As for the RF performances,the gate extrinsic parasitic capacitance decreases and the intrinsic transconductance increases after the gate stem height has been increased, so the RF performances of device are obviously improved. The high gate stem device yields a maximum ft of 270 GHz and fmax of 460 GHz, while the short gate stem device has a maximum ft of 240 GHz and the fmax of 370 GHz.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775191,61404115,61434006,and 11475256)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province,China(Grant No.18IRTSTHN016)the Development Fund for Outstanding Young Teachers in Zhengzhou University of China(Grant No.1521317004)
文摘InP-based high electron mobility transistors（HEMTs） will be affected by protons from different directions in space radiation applications. The proton irradiation effects on InAlAs/InGaAs hetero-junction structures of InP-based HEMTs are studied at incident angles ranging from 0 to 89.9° by SRIM software. With the increase of proton incident angle, the change trend of induced vacancy defects in the InAlAs/InGaAs hetero-junction region is consistent with the vacancy energy loss trend of incident protons. Namely, they both have shown an initial increase, followed by a decrease after incident angle has reached 30°. Besides, the average range and ultimate stopping positions of incident protons shift gradually from buffer layer to hetero-junction region, and then go up to gate metal. Finally, the electrical characteristics of InP-based HEMTs are investigated after proton irradiation at different incident angles by Sentaurus-TCAD. The induced vacancy defects are considered self-consistently through solving Poisson＇s and current continuity equations. Consequently, the extrinsic transconductance, pinch-off voltage and channel current demonstrate the most serious degradation at the incident angle of 30？, which can be accounted for the most severe carrier sheet density reduction under this condition.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775191,61404115,61434006,and 11475256)the Promotion Funding for Excellent Young Backbone Teacher of Henan Province,China(Grant No.2019GGJS017)。
文摘An anti-radiation structure of In P-based high electron mobility transistor(HEMT) has been proposed and optimized with double Si-doped planes. The additional Si-doped plane under channel layer has made a huge promotion in channel current, transconductance, current gain cut-off frequency, and maximum oscillation frequency of In P-based HEMTs. Moreover, direct current(DC) and radio frequency(RF) characteristic properties and their reduction rates have been compared in detail between single Si-doped and double Si-doped structures after 75-keV proton irradiation with dose of 5× 10^(11) cm^(-2),1× 10^(12) cm^(-2), and 5× 10^(12) cm^(-2). DC and RF characteristics for both structures are observed to decrease gradually as irradiation dose rises, which particularly show a drastic drop at dose of 5× 10^(12) cm^(-2). Besides, characteristic degradation degree of the double Si-doped structure is significantly lower than that of the single Si-doped structure, especially at large proton irradiation dose. The enhancement of proton radiation tolerance by the insertion of another Si-doped plane could be accounted for the tremendously increased native carriers, which are bound to weaken substantially the carrier removal effect by irradiation-induced defects.
基金supported by the National Natural Science Foundation of China(Grant Nos.61874036,62174041,and61434006)the Open Project of State Key Laboratory of ASIC and System(Grant No.KVH1233021)+3 种基金the Opening Foundation of the State Key Laboratory of Advanced Materials and Electronic Components(Grant No.FHR-JS-201909007)the Guangxi Innovation Research Team Project(Grant Nos.2018GXNSFGA281004 and 2018GXNSFBA281152)the Guangxi Innovation Driven Development Special Fund Project(Grant No.AA19254015)the Guangxi Key Laboratory of Precision Navigation Technology and Application Project(Grant Nos.DH201906,DH202020,and DH202001)。
文摘A double-recessed offset gate process technology for In P-based high electron mobility transistors(HEMTs)has been developed in this paper.Single-recessed and double-recessed HEMTs with different gate offsets have been fabricated and characterized.Compared with single-recessed devices,the maximum drain-source current(I_(D,max))and maximum extrinsic transconductance(g_(m,max))of double-recessed devices decreased due to the increase in series resistances.However,in terms of RF performance,double-recessed HEMTs achieved higher maximum oscillation frequency(f_(MAX))by reducing drain output conductance(g_(m,max))and drain to gate capacitance(C_gd).In addition,further improvement of fMAXwas observed by adjusting the gate offset of double-recessed devices.This can be explained by suppressing the ratio of C_(gd)to source to gate capacitance(C_gd)by extending drain-side recess length(Lrd).Compared with the single-recessed HEMTs,the f;of double-recessed offset gate HEMTs was increased by about 20%.
基金Project supported by the National Nature Science Foundation of China(Grant No.61434006)。
文摘A set of 100-nm gate-length In P-based high electron mobility transistors(HEMTs)were designed and fabricated with different gate offsets in gate recess.A novel technology was proposed for independent definition of gate recess and T-shaped gate by electron beam lithography.DC and RF measurement was conducted.With the gate offset varying from drain side to source side,the maximum drain current(I_(ds,max))and transconductance(g_(m,max))increased.In the meantime,fTdecreased while f;increased,and the highest fmax of 1096 GHz was obtained.It can be explained by the increase of gate-source capacitance and the decrease of gate-drain capacitance and source resistance.Output conductance was also suppressed by gate offset toward source side.This provides simple and flexible device parameter selection for HEMTs of different usages.
基金the National Natural Science Foundation of China(62304252)the Youth Innovation Promotion Association of Chinese Academy Sciences(CAS)and IMECAS-HKUST-Joint Laboratory of Microelectronics。
基金Project supported by the National Natural Science Foundation of China （Nos. 61404115 and 61434006）, the Program for Innovative Research Team （in Science and Technology） in University of Henan Province, China （No. 18IRTSTHN016）, and the Development Fund for Outstanding Young Teachers in Zhengzhou University, China （No. 1521317004）
基金Project supported by the National Natural Science Foundation of China(No.60806024)the Fundamental Research Funds for the Central Universities,China(No.XDJK2009C020).
文摘120 nm gate-length In_（0.7）Ga_（0.3）As/In_（0.52）Al_（0.48） As InP-based high electron mobility transitions（HEMTs） are fabricated by a new T-shaped gate electron beam lithograph（EBL） technology,which is achieved by the use of a PMMA/PMGI/ZEP520/PMGI four-layer photoresistor stack.These devices also demonstrate excellent DC and RF characteristics：the transconductance,maximum saturation drain-to-source current,threshold voltage,maximum current gain frequency,and maximum power-gain cutoff frequency of InGaAs/InAlAs HEMTs is 520 mS/mm,446 mA/mm, -1.0 V,141 GHz and 120 GHz,respectively.The material structure and all the device fabrication technology in this work were developed by our group.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.60806024)the Fundamental Research Funds for Central University,China(No.XDJK2009C020)
文摘A new PMMA/PMGI/ZEP520/PMGI four-layer resistor electron beam lithography technology is successfully developed and used to fabricate a 120 nm gate-length lattice-matched In_（0.53）Ga_（0.47）As/In_（0.52）Al_（0.48） As InP-based HEMT,of which the material structure is successfully designed and optimized by our group.A 980 nm ultra-wide T-gate head,which is nearly as wide as 8 times the gatefoot（120 nm）,is successfully obtained,and the excellent T-gate profile greatly reduces the parasitic resistance and capacitance effect and effectively enhances the RF performances. These fabricated devices demonstrate excellent DC and RF performances such as a maximum current gain frequency of 190 GHz and a unilateral power-gain gain frequency of 146 GHz.
