EFFECT OF EXPONENTIALLY GRADED BASE DOPING ON THE PERFORMANCE OF GAAS/A1GAAS HETEROJUNCTION BIPOLAR-TRANSISTORS

被引：18

作者：

STREIT, DC ^{[1
]}

HAFIZI, ME ^{[1
]}

UMEMOTO, DK ^{[1
]}

VELEBIR, JR ^{[1
]}

TRAN, LT ^{[1
]}

OKI, AK ^{[1
]}

KIM, ME ^{[1
]}

WANG, SK ^{[1
]}

KIM, CW ^{[1
]}

SADWICK, LP ^{[1
]}

HWU, RJ ^{[1
]}

机构：

[1] UNIV UTAH,DEPT ELECT ENGN,SALT LAKE CITY,UT 84112

来源：

IEEE ELECTRON DEVICE LETTERS | 1991年 / 12卷 / 05期

关键词：

D O I：

10.1109/55.79553

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

We have fabricated n-p-n GaAs/AlGaAs heterojunction bipolar transistors (HBT's) with base doping graded exponentially from 5 x 10(19) cm-3 at the emitter edge to 5 x 10(18) cm-3 at the collector edge. The built-in field due to the exponentially graded doping profile significantly reduces base transit time, despite bandgap narrowing associated with high base doping. Compared to devices with the same base thickness and uniform base doping of 1 x 10(19) cm-3, the cutoff frequency is increased from 22 to 31 GHz and maximum frequency of oscillation is increased from 40 to 58 GHz. Exponentially graded base doping also results in consistently higher common-emitter current gain than uniform base doping, even though the Gummel number is twice as high and the base resistance is reduced by 40%. We believe these to be the first reported results of the effect of exponentially graded base doping on the performance of HBT's.

引用

页码：194 / 196

页数：3

共 13 条

[1] GAALAS/GAAS HETEROJUNCTION BIPOLAR-TRANSISTORS - ISSUES AND PROSPECTS FOR APPLICATION [J].