Novel fabrication of C-doped base InGaAs/InP DHBT structures for high speed circuit applications

R. F. Kopf, R. A. Hamm, R. J. Malik, R. W. Ryan, J. Burm, A. Tate, Y. K. Chen, G. Georgiou, D. V. Lang, M. Geva, F. Ren

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


We have fabricated InGaAs/InP based DHBTs for high speed circuit applications. A process involving both wet chemical and ECR plasma etching was developed. Carbon was employed as the p-type dopant of the base layer for excellent device stability. Both the emitter-base and base-collector regions were graded using quaternary InGaAsP alloys. The extrinsic emitter-base junction is buried for junction passivation to improve device reliability. The use of an InP collector structure with the graded region results in high breakdown voltages of 8-10 V, with no current blocking. The entire structure is encapsulated with spin-on-glass. These devices show no degradation in d.c. characteristics after operation at an emitter current density of 90 kA cm-2 and a collector bias, VCE, of 2 V at room temperature for over 500 h. Typical common emitter current gain was 50. An ft, of 80 and fmax of 155 GHz were achieved for 2 x 4 μm2 emitter size devices.

Original languageEnglish (US)
Pages (from-to)2239-2250
Number of pages12
JournalSolid-State Electronics
Issue number12
StatePublished - Dec 1998
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Materials Chemistry
  • Electrical and Electronic Engineering


Dive into the research topics of 'Novel fabrication of C-doped base InGaAs/InP DHBT structures for high speed circuit applications'. Together they form a unique fingerprint.

Cite this