Design and performance of InP/GaAsSb/InP double heterojunction bipolar transistors
Bibliographic record
Abstract
We report a fabrication technique for 1 μm wide emitter finger InP/GaAs0.51Sb0.49/InP double heterojunction bipolar transistors (DHBTs). In this technology, we use a wet-etched undercut airbridge technique to provide device isolation while minimizing parasitics and avoiding damage to semiconductor layers by dry etching. The metalorganic chemical vapor deposition-grown InP/GaAs0.51Sb0.49/InP NpN structure takes advantage of a staggered (“type II”) band lineup at InP/GaAs0.51Sb0.49 interfaces: in this material system the GaAs0.51Sb0.49 base conduction band edge lies 0.18 eV above the InP collector conduction band, thus enabling the implementation of InP collectors free of the collector current blocking effect encountered in conventional Ga0.47In0.53As base DHBTs. The structure results in very low collector current offset voltages, low emitter-base turn-on voltages, and very nearly ideal base and collector current characteristics with junction ideality factors of nB=1.05 and nC=1.00 and DHBTs with cutoff frequencies as high as 106 GHz and breakdown voltages of BVceo=8 V have been implemented, and represent the highest performance ever achieved in this material system. The low turn-on and offset voltages make InP/GaAs0.51Sb0.49/InP DHBTs attractive for long talk-time wireless communication systems, yet these devices can also be adapted to power applications by virtue of their InP collector. Excellent performances are obtained without the need for complex and critical optimizations thanks to the favorable band lineups: all junctions are abrupt and no grading was performed in doping or in material composition.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".