We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) dem... more We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating a simultaneous f t /f max of 465/660 GHz and operating at power densities in excess of 50 mW/m 2 . To our knowledge this is the smallest junction width reported for a III-V DHBT. The narrow 110 nm emitter junction permits the devices to be biased simultaneously at high voltages and high current densities (J e ) with peak RF performance at 41 mW/m 2 (J e = 23.6 mA/m 2 , V ce = 1.75 V). Devices incorporate low contact resistance, refractory, in-situ Mo emitter contact to a highly doped, regrown InGaAs cap. A low stress, sputter deposited, refractory, dry-etched W/Ti 0.1 W 0.9 emitter metal process was developed demonstrating both high emitter yield and scalability to sub-100 nm junctions. Previously reported dry etch processes involving Ti/Ti 0.1 W 0.9 metals could not be scaled below 180 nm junction widths due to high metal stress resulting in very low emitter yield [1, 2]. The emitter metal contacts reported here are 100 nm wide and the emitter-base junction width is 110 nm. On-wafer Through-Reflect-Line (TRL) calibration structures were used to measure the RF performance of devices from 140 -180 GHz.
We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstra... more We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating simultaneous 430-GHz f τ and 800-GHz f max . The devices were fabricated using a triple mesa process with dry-etched refractory metals for emitter contact formation. The devices incorporate a 30-nm-thick InP emitter semiconductor which enables a wet-etch emitter process demonstrating 270-nm-wide emitter-base junctions. At peak RF performance, the device is operating at 30 mW/μm 2 with J c = 18.4 mA/μm 2 and V ce = 1.64 V. The devices show a peak DC common-emitter current gain (β) ∼ 20 and V BR,CEO = 2.5 V. Index Terms-Heterojunction bipolar transistor (HBT), indium phosphide (InP).
ABSTRACT Given adequately low source/drain (S/D) access resistivity and dielectric interface trap... more ABSTRACT Given adequately low source/drain (S/D) access resistivity and dielectric interface trap density (Raccess
2009 IEEE International Conference on Indium Phosphide & Related Materials, 2009
Type I InP/InGaAs/InP double heterojunction bipolar transistors were fabricated using a simple me... more Type I InP/InGaAs/InP double heterojunction bipolar transistors were fabricated using a simple mesa struc-ture, where emitter junction widths have been scaled from 250 nm to 200 nm. These devices exhibit fmax in ex-cess of 800 GHz, and fτ = 360 GHz. Greater than fifty percent ...
ABSTRACT We report 220 nm InP double heterojunction bipolar transistors (DHBTs) demonstrating ft ... more ABSTRACT We report 220 nm InP double heterojunction bipolar transistors (DHBTs) demonstrating ft = 480 GHz and fmax = 1.0 THz. Improvements in the emitter and base processes have made it possible to achieve a 1.0 THz fmax even at 220 nm wide emitter-base junction with a 1.1 μm wide base-collector mesa. A vertical emitter metal etch profile, wet-etched thin InP emitter semiconductor with less than 10 nm undercut and self-aligned base contact deposition reduces the emitter semiconductor-base metal gap (Wgap) to ~ 10 nm, thereby significantly reducing the gap resistance term (Rgap) in the total base access resistance (Rbb), enabling a high fmax device. Reduction in the total collector base capacitance (Ccb) through undercut in the base mesa below base post further improved fmax. These devices employ a Mo/W/TiW refractory emitter metal contact which allows biasing the transistors at high emitter current densities (Je) without problems of electromigration or contact diffusion under electrical stress.
We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) dem... more We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating a simultaneous f t /f max of 465/660 GHz and operating at power densities in excess of 50 mW/m 2 . To our knowledge this is the smallest junction width reported for a III-V DHBT. The narrow 110 nm emitter junction permits the devices to be biased simultaneously at high voltages and high current densities (J e ) with peak RF performance at 41 mW/m 2 (J e = 23.6 mA/m 2 , V ce = 1.75 V). Devices incorporate low contact resistance, refractory, in-situ Mo emitter contact to a highly doped, regrown InGaAs cap. A low stress, sputter deposited, refractory, dry-etched W/Ti 0.1 W 0.9 emitter metal process was developed demonstrating both high emitter yield and scalability to sub-100 nm junctions. Previously reported dry etch processes involving Ti/Ti 0.1 W 0.9 metals could not be scaled below 180 nm junction widths due to high metal stress resulting in very low emitter yield [1, 2]. The emitter metal contacts reported here are 100 nm wide and the emitter-base junction width is 110 nm. On-wafer Through-Reflect-Line (TRL) calibration structures were used to measure the RF performance of devices from 140 -180 GHz.
2009 IEEE International Conference on Indium Phosphide & Related Materials, 2009
... RA Hamm, R. Ryan; Electron Device Letters, IEEE , vol.17, no.2, pp.62-64, Feb 1996 (5) Adam M... more ... RA Hamm, R. Ryan; Electron Device Letters, IEEE , vol.17, no.2, pp.62-64, Feb 1996 (5) Adam M. Crook, Erik Lind, Zach Griffith, Mark JW ... on the Phys and Chem of Surfaces and Interfaces, PCSI-36, Santa Barbara, 11-15 Jan 2009 (13) H. Ueng, DB Janes, KJ Webb; IEEE Trans ...
A 0.25m InP DHBT process has been developed for THz frequency integrated circuits. A 0.25x4m 2 HB... more A 0.25m InP DHBT process has been developed for THz frequency integrated circuits. A 0.25x4m 2 HBT exhibits an extrapolated ft/fmax of 430GHz/1.03THz at IC =11mA, VCE= 1.8V. The transistors achieve this performance while maintaining a common-emitter breakdown voltage (BVCEO) >4V. Thin-film interconnects and backside wafer processes have been developed to support selected IC demonstrations. The technology has been used to build fundamental oscillators, amplifiers and dynamic frequency dividers all operating at >300GHz. Additionally, increasingly complex circuits such as a full PLL have been demonstrated.
We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstra... more We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating simultaneous 430-GHz f τ and 800-GHz f max . The devices were fabricated using a triple mesa process with dry-etched refractory metals for emitter contact formation. The devices incorporate a 30-nm-thick InP emitter semiconductor which enables a wet-etch emitter process demonstrating 270-nm-wide emitter-base junctions. At peak RF performance, the device is operating at 30 mW/μm 2 with J c = 18.4 mA/μm 2 and V ce = 1.64 V. The devices show a peak DC common-emitter current gain (β) ∼ 20 and V BR,CEO = 2.5 V. Index Terms-Heterojunction bipolar transistor (HBT), indium phosphide (InP).
We examine the feasibility of developing bipolar transistors with power-gain cutoff frequencies o... more We examine the feasibility of developing bipolar transistors with power-gain cutoff frequencies of 1-3 THz. High bandwidths are obtained by scaling; the critical limits to such scaling are the requirements that the current density increase in proportion to the square of bandwidth and that the metalsemiconductor contact resistivities vary as the inverse square of device bandwidth. Transistors with 755 GHz max f and 324 GHz amplifiers have been demonstrated. Transistors with target max f over 1 THz are in development.
ABSTRACT We report InP/In0.53Ga0.47As/InP double heterojunction bipolar transistors (DHBTs) demon... more ABSTRACT We report InP/In0.53Ga0.47As/InP double heterojunction bipolar transistors (DHBTs) demonstrating simultaneous 460 GHz fτ and 850 GHz fmax. The devices were fabricated using a triple mesa process with dry-etched, refractory metals for emitter contact formation. The devices incorporate a 35 nm thick InP emitter which 52d enables a wet etch emitter process demonstrating 220 nm wide emitter-base junctions with less than 10 nm undercut in the emitter semiconductor below emitter metal. This reduces the gap between base metal contact and emitter semiconductor causing significant reduction in emitter-base gap resistance (Rgap) component of the total base access resistance (Rbb), leading to an increase in observed fmax. At peak RF performance, the device is operating at 32 mW/μm2 with Je = 19.4 mA/μm2 and Vce = 1.66 V. The devices show a DC common emitter current gain (β) ~20 and VBR,CEO = 3.7 V.
We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) dem... more We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating a simultaneous f t /f max of 465/660 GHz and operating at power densities in excess of 50 mW/m 2 . To our knowledge this is the smallest junction width reported for a III-V DHBT. The narrow 110 nm emitter junction permits the devices to be biased simultaneously at high voltages and high current densities (J e ) with peak RF performance at 41 mW/m 2 (J e = 23.6 mA/m 2 , V ce = 1.75 V). Devices incorporate low contact resistance, refractory, in-situ Mo emitter contact to a highly doped, regrown InGaAs cap. A low stress, sputter deposited, refractory, dry-etched W/Ti 0.1 W 0.9 emitter metal process was developed demonstrating both high emitter yield and scalability to sub-100 nm junctions. Previously reported dry etch processes involving Ti/Ti 0.1 W 0.9 metals could not be scaled below 180 nm junction widths due to high metal stress resulting in very low emitter yield [1, 2]. The emitter metal contacts reported here are 100 nm wide and the emitter-base junction width is 110 nm. On-wafer Through-Reflect-Line (TRL) calibration structures were used to measure the RF performance of devices from 140 -180 GHz.
We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstra... more We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating simultaneous 430-GHz f τ and 800-GHz f max . The devices were fabricated using a triple mesa process with dry-etched refractory metals for emitter contact formation. The devices incorporate a 30-nm-thick InP emitter semiconductor which enables a wet-etch emitter process demonstrating 270-nm-wide emitter-base junctions. At peak RF performance, the device is operating at 30 mW/μm 2 with J c = 18.4 mA/μm 2 and V ce = 1.64 V. The devices show a peak DC common-emitter current gain (β) ∼ 20 and V BR,CEO = 2.5 V. Index Terms-Heterojunction bipolar transistor (HBT), indium phosphide (InP).
ABSTRACT Given adequately low source/drain (S/D) access resistivity and dielectric interface trap... more ABSTRACT Given adequately low source/drain (S/D) access resistivity and dielectric interface trap density (Raccess
2009 IEEE International Conference on Indium Phosphide & Related Materials, 2009
Type I InP/InGaAs/InP double heterojunction bipolar transistors were fabricated using a simple me... more Type I InP/InGaAs/InP double heterojunction bipolar transistors were fabricated using a simple mesa struc-ture, where emitter junction widths have been scaled from 250 nm to 200 nm. These devices exhibit fmax in ex-cess of 800 GHz, and fτ = 360 GHz. Greater than fifty percent ...
ABSTRACT We report 220 nm InP double heterojunction bipolar transistors (DHBTs) demonstrating ft ... more ABSTRACT We report 220 nm InP double heterojunction bipolar transistors (DHBTs) demonstrating ft = 480 GHz and fmax = 1.0 THz. Improvements in the emitter and base processes have made it possible to achieve a 1.0 THz fmax even at 220 nm wide emitter-base junction with a 1.1 μm wide base-collector mesa. A vertical emitter metal etch profile, wet-etched thin InP emitter semiconductor with less than 10 nm undercut and self-aligned base contact deposition reduces the emitter semiconductor-base metal gap (Wgap) to ~ 10 nm, thereby significantly reducing the gap resistance term (Rgap) in the total base access resistance (Rbb), enabling a high fmax device. Reduction in the total collector base capacitance (Ccb) through undercut in the base mesa below base post further improved fmax. These devices employ a Mo/W/TiW refractory emitter metal contact which allows biasing the transistors at high emitter current densities (Je) without problems of electromigration or contact diffusion under electrical stress.
We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) dem... more We report a 110 nm InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating a simultaneous f t /f max of 465/660 GHz and operating at power densities in excess of 50 mW/m 2 . To our knowledge this is the smallest junction width reported for a III-V DHBT. The narrow 110 nm emitter junction permits the devices to be biased simultaneously at high voltages and high current densities (J e ) with peak RF performance at 41 mW/m 2 (J e = 23.6 mA/m 2 , V ce = 1.75 V). Devices incorporate low contact resistance, refractory, in-situ Mo emitter contact to a highly doped, regrown InGaAs cap. A low stress, sputter deposited, refractory, dry-etched W/Ti 0.1 W 0.9 emitter metal process was developed demonstrating both high emitter yield and scalability to sub-100 nm junctions. Previously reported dry etch processes involving Ti/Ti 0.1 W 0.9 metals could not be scaled below 180 nm junction widths due to high metal stress resulting in very low emitter yield [1, 2]. The emitter metal contacts reported here are 100 nm wide and the emitter-base junction width is 110 nm. On-wafer Through-Reflect-Line (TRL) calibration structures were used to measure the RF performance of devices from 140 -180 GHz.
2009 IEEE International Conference on Indium Phosphide & Related Materials, 2009
... RA Hamm, R. Ryan; Electron Device Letters, IEEE , vol.17, no.2, pp.62-64, Feb 1996 (5) Adam M... more ... RA Hamm, R. Ryan; Electron Device Letters, IEEE , vol.17, no.2, pp.62-64, Feb 1996 (5) Adam M. Crook, Erik Lind, Zach Griffith, Mark JW ... on the Phys and Chem of Surfaces and Interfaces, PCSI-36, Santa Barbara, 11-15 Jan 2009 (13) H. Ueng, DB Janes, KJ Webb; IEEE Trans ...
A 0.25m InP DHBT process has been developed for THz frequency integrated circuits. A 0.25x4m 2 HB... more A 0.25m InP DHBT process has been developed for THz frequency integrated circuits. A 0.25x4m 2 HBT exhibits an extrapolated ft/fmax of 430GHz/1.03THz at IC =11mA, VCE= 1.8V. The transistors achieve this performance while maintaining a common-emitter breakdown voltage (BVCEO) >4V. Thin-film interconnects and backside wafer processes have been developed to support selected IC demonstrations. The technology has been used to build fundamental oscillators, amplifiers and dynamic frequency dividers all operating at >300GHz. Additionally, increasingly complex circuits such as a full PLL have been demonstrated.
We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstra... more We report an InP/In 0.53 Ga 0.47 As/InP double heterojunction bipolar transistor (DHBT) demonstrating simultaneous 430-GHz f τ and 800-GHz f max . The devices were fabricated using a triple mesa process with dry-etched refractory metals for emitter contact formation. The devices incorporate a 30-nm-thick InP emitter semiconductor which enables a wet-etch emitter process demonstrating 270-nm-wide emitter-base junctions. At peak RF performance, the device is operating at 30 mW/μm 2 with J c = 18.4 mA/μm 2 and V ce = 1.64 V. The devices show a peak DC common-emitter current gain (β) ∼ 20 and V BR,CEO = 2.5 V. Index Terms-Heterojunction bipolar transistor (HBT), indium phosphide (InP).
We examine the feasibility of developing bipolar transistors with power-gain cutoff frequencies o... more We examine the feasibility of developing bipolar transistors with power-gain cutoff frequencies of 1-3 THz. High bandwidths are obtained by scaling; the critical limits to such scaling are the requirements that the current density increase in proportion to the square of bandwidth and that the metalsemiconductor contact resistivities vary as the inverse square of device bandwidth. Transistors with 755 GHz max f and 324 GHz amplifiers have been demonstrated. Transistors with target max f over 1 THz are in development.
ABSTRACT We report InP/In0.53Ga0.47As/InP double heterojunction bipolar transistors (DHBTs) demon... more ABSTRACT We report InP/In0.53Ga0.47As/InP double heterojunction bipolar transistors (DHBTs) demonstrating simultaneous 460 GHz fτ and 850 GHz fmax. The devices were fabricated using a triple mesa process with dry-etched, refractory metals for emitter contact formation. The devices incorporate a 35 nm thick InP emitter which 52d enables a wet etch emitter process demonstrating 220 nm wide emitter-base junctions with less than 10 nm undercut in the emitter semiconductor below emitter metal. This reduces the gap between base metal contact and emitter semiconductor causing significant reduction in emitter-base gap resistance (Rgap) component of the total base access resistance (Rbb), leading to an increase in observed fmax. At peak RF performance, the device is operating at 32 mW/μm2 with Je = 19.4 mA/μm2 and Vce = 1.66 V. The devices show a DC common emitter current gain (β) ~20 and VBR,CEO = 3.7 V.
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Papers by Evan Lobisser