{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

final_fall01 - Department of Electrical and Computer...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Department of Electrical and Computer Engineering UNIVERSITY OF BRITISH COLUMBIA EECE 480 SEMICONDUCTOR DEVICES FINAL EXAM, December 12, 2001 Time: 2.5 hours Answer 4 (FOUR) questions. All questions carry equal weight. No notes, calculators or books allowed. This exam consists of 2 pages 1. BJT (a) Give precise definitions for f T and f max as they apply to bipolar transistors. (b) Identify the various device features that determine f T and f max , and comment on their relative impor- tance. (c) Discuss how vertical shrinking and lateral shrinking of a BJT affect f T and f max . 2. HBT Consider an n-p-n HBT which has emitter and collector regions made from material A and base region made from material B . Material A has an electron affinity of 3 eV and a bandgap of 5 eV; the corresponding, respective quantities for material B are 4 eV and 2 eV. The emitter doping density is higher than that of the collector. (a) Construct the equilibrium energy band diagram, roughly to scale, of the HBT, showing the vacuum level, the conduction- and valence- band edges, and the Fermi level.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}