EE 3161 Semiconductor Devices
Spring 2008 | University of Minnesota Electrical and Computer Engineering
Midterm 2
Wednesday, April 16 at the usual lecture time and place. Open book, notes, and calculators allowed.
The usual prohibitions against communications devices apply.
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- Topics covered, as announced in lecture on April 14, are listed below.
Only material covered in class about diodes and BJTs will be covered directly. (Earlier topics may be used indirectly, but will not be the direct topic of a question.
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- Ch. 5: Diode Electrostatics
- sec 5.1:
- built-in voltage Vbi
- depletion approx.
- sec 5.2:
- junction types
- ρ, ε, and V distributions
- depletion widths xn , xp , W
- applied bias, band diagrams
- Ch. 6: Diode I-V
- sec 6.1: ideal diode equation
- minority carrier concentration
- which terms correspond to holes/electrons
- diffusion/drift currents
- closely related: ch. 3 sec 4: minority carrier diffusion equation
- sec 6.2: non-ideal diodes
- avalanche breakdown
- Zener breakdown
- reverse/forward recombination generation current IR-G (dominates in rev. and low forward biases!)
- high-level injection; series resistance
- sec 6.3: narrow base
- Ch. 7: There's Something About Diodes
- sec 7.2.1, 7.2.2: diode capacitance: what is it, voltage dependence, etc.
- Ch. 10: BJT Fundamentals
- for both pnp and npn devices:
- bias regions (active, cutoff, saturation)
- performance parameters β , αdc, γ , αT
- currents
- ρ, ε, and V distributions
- band diagrams
- Ch. 11: BJT Current Equations
- for both pnp and npn devices:
- sec 11.1.1 - 11.1.3: general I-V solutions
- sec 11.2.1 - 11.2.4: non-ideal BJTs
- base-width modulation
- punch-through
- avalanche
- recombination-generation current IR-G
- sec 11.2.5: geometrical effects: short emitter, series resistance
- NOT sec 11.3: Ebers-Moll model
- Ch. 12: BJT Switching
- for both pnp and npn devices:
- sec 12.2: (core material)
- also relevant: sec 6.3.1
- also relevant: sec 8.1, 8.2: rise time τR, storage delay time τSD
- NOT sec 12.1: hybrid-pi model
- Class score results