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. Pen

Research output: Contribution to journalConference articlepeer-review


We have fabricated in 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 V to 10 V, with no current blocking. The entire structure is encapsulated with spin-on-glass. These devices show no degradation in DC characteristics after operation at an emitter current density of 90 kA/cm2 and a collector bias, VCE, of 2 V at room temperature for over 500 hours. Typical common emitter current gain was 50. An ft of 80 and fmax of 155 GHz were achieved for 2×4 μm2 emitter size devices.

Original languageEnglish (US)
Pages (from-to)413-424
Number of pages12
JournalMaterials Research Society Symposium - Proceedings
StatePublished - 1997
Externally publishedYes
EventProceedings of the 1997 Fall MRS Symposium - Boston, MA, USA
Duration: Dec 1 1997Dec 4 1997

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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