Compound Semiconductor Devices
Lecture Notes
The white board files provided below correspond to lecture content captured with an electronic white board during class.
LEC # |
TOPICS |
1 |
Compound Semiconductors: The families (III-V's, II-VI's, IV-VI's, IV-IV's), alloys, Eg vs a; band structures (E vs k; Γ, L, X minima; direct vs. indirect gaps); crystal lattices, electrical properties, optical properties; trends in properties and the periodic table. The useful compounds. (PDF) |
2 |
Metal-Semiconductor Interfaces (Schottky Barriers): The compound semiconductor surface; Fermi level pinning. Theories of barrier formation and of current flow; diffusive vs. ballistic flow; contrasts with p-n diodes. Theory and practice of ohmic contacts. (PDF) |
3 |
Heterostructures: E-x Profiles: ΔEc, ΔEv, Ec(x), Ev(x); no(x), po(x); modulation doping. Conduction parallel to heterojunction; mobility in semiconductors and carrier scattering mechanisms. (PDF) |
4 |
Heterojunctions: Conduction normal to junction: I-V models and characteristics. Theory of graded layers; creation of internal carrier-specific fields. (PDF) |
5 |
Quantum Effect Structures: Quantum wells: theory, fabrication, observation (verification), and application. Quantum wires and dots. (PDF) |
6 |
Quantum Effect Structures (contd.): Coupled quantum structures: super lattices. Resonant tunneling: RTD structure and concept. I-V theory. Related devices and applications: RTD-load logic, memory cells. (PDF) |
7 |
Epitaxy: Concerns / constraints — lattice-matched systems; strained layers (pseudomorphic) — limits of thickness; impact of strain on bands, properties. (PDF - 1.1 MB) |
8 |
Epitaxy (contd.): Techniques — MOCVD, CBE, MBE (MO, GS, & SS). |
9 |
MESFETs: Basic concept, models for terminal characteristics; accounting for velocity saturation. Dynamic models: large signal switching transients; small signal, high f models. Fabrication sequences; application-specific designs (power, digital, low noise microwave). (PDF) |
10 |
MESFET Digital Logic Families: Performance criteria for logic. Logic families: normally-on logic (FL, BFL, SDFL); normally-off logic (DCFL); comparison offamilies; examples of fabrication sequences; performance data; state-of-the-art commercially. |
11 |
HFETs (Doped Channel): Concept; I-V model including velocity saturation; gate 2 characteristics; output conductance; applications of strained layers. |
12 |
HFETs (Modulation Doped): MODFETs — basic device, theory. Deep level problem (transconductance collapse); pseudomorphic solution. Telecommunications applications — key features: gain, bandwidth, linearly, noise. (PDF) |
13 |
HBTs: Concept: emitter efficiency, base transport, base resistance, junction capacitance. HJ collector and collector-up refinements. Applications of graded layers: control of HJ spikes; ballistic injection; problems with upper-valley minima. (PDF) |
14 |
HBTs (contd.): State-of-the-art commercial HBT technologies (III-V and IV-IV). (PDF - 2.4 MB) |
15 |
Light Emission and Absorption: Basic theory. Direct vs. indirect gap. Band-to-band and band-to-impurity transistions. (PDF) |
16 |
Dielectric Waveguides / Photonic Crystals: Basics of optical cavities and waveguides. Photonic crystal concepts, structures, issues. (PDF) |
17 |
Light Emitting Diodes: LEDs — structure, materials, characteristics (i-v, l-i, l-l), performance. Light extraction, current spreading, photon recycling. (PDF) |
18 |
LEDs (contd.): Applications in displays and illumination — considerations, current practice, recent commercial developments. (PDF - 1.7 MB) |
19 |
Laser Diodes: Feedback and stimulated emission. Cavity design; double heterostructure concept. Quantum well, wire, dot active regions. Strained layers; pseudomorphic active regions. (PDF) |
20/21 |
Laser Diodes (contd.): In-plane lasers: double heterostructure, quantum well, multi-contact, surface emitting. Vertical cavity surface emitting lasers (VCSELs). Modulation and control of emission. New structures and material systems including blue-green lasers and cascade lasers. |
22 |
Detectors: Structure and theory of basic types: p-i-n (conventional and unicarrier), APD, Schottky diode, m-s-m; resonant cavity concepts. (PDF - 1.9 MB) |
23 |
Detectors (contd.): Vertical vs. in-plane geometries. Quantum well intersubband photodetectors. (PDF) |
24 |
Modulators: Multiple quantum well structures, quantum confined Stark effect; SEED. Waveguide couplers, switches, modulators. |
25 |
OEICs (contd.): Approaches to integration and current state-of-the-art. Epitaxial stacks, multiple-epitaxial runs, epitaxy on processed electronics (GaAs-on-Si, GaAs-on-GaAs, Si-on-GaAs). Bonding. Hybrid integration. Self-assembly. (PDF - 3.5 MB) |
26 |
Quantum Effect Devices: Electron waveguides, single electron transistors, etc. |
27 |
Device Research Conference Preview / Industrial Overview: What's new and exciting this year in research and in the marketplace? |
Assignments
ASSIGNMENTS |
SOLUTIONS |
Problem Set 1 (PDF) |
(PDF) |
Problem Set 2 (PDF) |
(PDF) |
Problem Set 3 (PDF) |
(PDF) |