Aluminum-Graded-Base PNp AlGaAs/GaAs Heterojunction Transistor with 37 GHz Cut-Off Frequency

Atsushi KAMEYAMA; Alan MASSENGALE; Changhong DAI; James S. HARRIS, Jr.

Aluminum-Graded-Base PNp AlGaAs/GaAs Heterojunction Transistor with 37 GHz Cut-Off Frequency

Atsushi KAMEYAMA, Alan MASSENGALE, Changhong DAI, James S. HARRIS, Jr.

Full Text Views

0

Share
Cite this

Summary :

The base transit time of an Aluminum-graded-base PNp AlGaAs/GaAs heterojunction bipolar transistor (HBT) was studied in order to clarify the effect of aluminum grading in the base. Theoretical analysis using a classical drift diffusion model with velocity saturation at the base-collector junction and a high base quasielectric field (58 keV/cm) created by 20%-aluminum linear grading in a 400 base, leads to a base transit time (τ_b) of 0.9 ps. The base transit time is reduced by four times, compared to the base transit time of 3.6 ps without aluminum grading in the base. In order to demonstrate this advantage, we fabricated aluminum-graded-base PNp AlGaAs/GaAs heterojunction transistor which employs a 20%-aluminum linear graded 400 -wide base. The device with a 2 µm 10 µm emitter showed high RF performance with a cut-off frequency (f_t) of 37 GHz and a maximum oscillation frequency (f_max) of 30 GHz at a collector current density of 3.4 10⁴ A/cm². Further analysis using direct parameter extraction of a small signal circuit model under the collector current density of 1.1-9.910⁴ A/cm² indicated the intrinsic transit time, which is the sum of the base transit time and the collector depletion layer transit time (τ_SC), was as low as 2.3 ps under lowinjection level. Subtracting the collector depletion-layer transit time from the intrinsic time leads to a base transit time of 1.1 ps, which is close to the theoretical base transit time and is the shortest value ever reported. The structure is very attractive for pnp-type AlGaAs HBTs combined with Npn HBTs for complementary applications.

Publication: IEICE TRANSACTIONS on Electronics Vol.E79-C No.4 pp.518-523

Publication Date: 1996/04/25

Publicized

Online ISSN

DOI

Type of Manuscript: Special Section PAPER (Special Issue on Ultra-High-Speed LSIs)

Category

Cite this

Copy

Atsushi KAMEYAMA, Alan MASSENGALE, Changhong DAI, James S. HARRIS, Jr., "Aluminum-Graded-Base PNp AlGaAs/GaAs Heterojunction Transistor with 37 GHz Cut-Off Frequency" in IEICE TRANSACTIONS on Electronics, vol. E79-C, no. 4, pp. 518-523, April 1996, doi: .
Abstract: The base transit time of an Aluminum-graded-base PNp AlGaAs/GaAs heterojunction bipolar transistor (HBT) was studied in order to clarify the effect of aluminum grading in the base. Theoretical analysis using a classical drift diffusion model with velocity saturation at the base-collector junction and a high base quasielectric field (58 keV/cm) created by 20%-aluminum linear grading in a 400 base, leads to a base transit time (τ_b) of 0.9 ps. The base transit time is reduced by four times, compared to the base transit time of 3.6 ps without aluminum grading in the base. In order to demonstrate this advantage, we fabricated aluminum-graded-base PNp AlGaAs/GaAs heterojunction transistor which employs a 20%-aluminum linear graded 400 -wide base. The device with a 2 µm 10 µm emitter showed high RF performance with a cut-off frequency (f_t) of 37 GHz and a maximum oscillation frequency (f_max) of 30 GHz at a collector current density of 3.4 10⁴ A/cm². Further analysis using direct parameter extraction of a small signal circuit model under the collector current density of 1.1-9.910⁴ A/cm² indicated the intrinsic transit time, which is the sum of the base transit time and the collector depletion layer transit time (τ_SC), was as low as 2.3 ps under lowinjection level. Subtracting the collector depletion-layer transit time from the intrinsic time leads to a base transit time of 1.1 ps, which is close to the theoretical base transit time and is the shortest value ever reported. The structure is very attractive for pnp-type AlGaAs HBTs combined with Npn HBTs for complementary applications.
URL: https://globals.ieice.org/en_transactions/electronics/10.1587/e79-c_4_518/_p

Copy

@ARTICLE{e79-c_4_518,
author={Atsushi KAMEYAMA, Alan MASSENGALE, Changhong DAI, James S. HARRIS, Jr., },
journal={IEICE TRANSACTIONS on Electronics},
title={Aluminum-Graded-Base PNp AlGaAs/GaAs Heterojunction Transistor with 37 GHz Cut-Off Frequency},
year={1996},
volume={E79-C},
number={4},
pages={518-523},
abstract={The base transit time of an Aluminum-graded-base PNp AlGaAs/GaAs heterojunction bipolar transistor (HBT) was studied in order to clarify the effect of aluminum grading in the base. Theoretical analysis using a classical drift diffusion model with velocity saturation at the base-collector junction and a high base quasielectric field (58 keV/cm) created by 20%-aluminum linear grading in a 400 base, leads to a base transit time (τ_b) of 0.9 ps. The base transit time is reduced by four times, compared to the base transit time of 3.6 ps without aluminum grading in the base. In order to demonstrate this advantage, we fabricated aluminum-graded-base PNp AlGaAs/GaAs heterojunction transistor which employs a 20%-aluminum linear graded 400 -wide base. The device with a 2 µm 10 µm emitter showed high RF performance with a cut-off frequency (f_t) of 37 GHz and a maximum oscillation frequency (f_max) of 30 GHz at a collector current density of 3.4 10⁴ A/cm². Further analysis using direct parameter extraction of a small signal circuit model under the collector current density of 1.1-9.910⁴ A/cm² indicated the intrinsic transit time, which is the sum of the base transit time and the collector depletion layer transit time (τ_SC), was as low as 2.3 ps under lowinjection level. Subtracting the collector depletion-layer transit time from the intrinsic time leads to a base transit time of 1.1 ps, which is close to the theoretical base transit time and is the shortest value ever reported. The structure is very attractive for pnp-type AlGaAs HBTs combined with Npn HBTs for complementary applications.},
keywords={},
doi={},
ISSN={},
month={April},}

Copy

TY - JOUR
TI - Aluminum-Graded-Base PNp AlGaAs/GaAs Heterojunction Transistor with 37 GHz Cut-Off Frequency
T2 - IEICE TRANSACTIONS on Electronics
SP - 518
EP - 523
AU - Atsushi KAMEYAMA
AU - Alan MASSENGALE
AU - Changhong DAI
AU - James S. HARRIS
AU - Jr.
PY - 1996
DO -
JO - IEICE TRANSACTIONS on Electronics
SN -
VL - E79-C
IS - 4
JA - IEICE TRANSACTIONS on Electronics
Y1 - April 1996
AB - The base transit time of an Aluminum-graded-base PNp AlGaAs/GaAs heterojunction bipolar transistor (HBT) was studied in order to clarify the effect of aluminum grading in the base. Theoretical analysis using a classical drift diffusion model with velocity saturation at the base-collector junction and a high base quasielectric field (58 keV/cm) created by 20%-aluminum linear grading in a 400 base, leads to a base transit time (τ_b) of 0.9 ps. The base transit time is reduced by four times, compared to the base transit time of 3.6 ps without aluminum grading in the base. In order to demonstrate this advantage, we fabricated aluminum-graded-base PNp AlGaAs/GaAs heterojunction transistor which employs a 20%-aluminum linear graded 400 -wide base. The device with a 2 µm 10 µm emitter showed high RF performance with a cut-off frequency (f_t) of 37 GHz and a maximum oscillation frequency (f_max) of 30 GHz at a collector current density of 3.4 10⁴ A/cm². Further analysis using direct parameter extraction of a small signal circuit model under the collector current density of 1.1-9.910⁴ A/cm² indicated the intrinsic transit time, which is the sum of the base transit time and the collector depletion layer transit time (τ_SC), was as low as 2.3 ps under lowinjection level. Subtracting the collector depletion-layer transit time from the intrinsic time leads to a base transit time of 1.1 ps, which is close to the theoretical base transit time and is the shortest value ever reported. The structure is very attractive for pnp-type AlGaAs HBTs combined with Npn HBTs for complementary applications.
ER -