Semiconductor Materials — Family Index
1. At a glance
Semiconductors are the substrate of every active electronic and optoelectronic device. Selection is driven by bandgap (controls cutoff wavelength and intrinsic carrier density), carrier mobility (speed), breakdown field (voltage handling), thermal conductivity (power density), and substrate availability/cost. The major families:
- Elemental (Group IV): Si, Ge. Indirect-gap, no efficient light emission, but unmatched processing maturity (Si) and high mobility (Ge).
- III-V binary: GaAs, GaN, InP, GaP, AlN, InN, InAs, InSb. Mostly direct-gap → photonics + high-speed electronics.
- III-V ternary / quaternary: AlGaAs, InGaAs, InGaAsP, AlGaN, InGaN, InAlGaN. Bandgap engineered by composition for laser/LED/HEMT.
- II-VI: CdTe, HgCdTe (MCT), ZnSe, ZnO, CdZnTe. IR detection, thin-film PV, transparent conductors.
- Wide-bandgap (WBG, E_g ≥ ~2.3 eV): SiC, GaN, ZnO. Power switching, RF, blue/UV.
- Ultra-wide-bandgap (UWBG, E_g ≥ ~4 eV): β-Ga₂O₃, diamond, AlN. Multi-kV emerging power devices.
- Organic: pentacene, rubrene, P3HT, PCBM, Alq3, polyfluorenes. OLED displays (mature), OPV (niche), OFET (niche).
- 2D / van der Waals: graphene, MoS₂, WSe₂, hBN, black phosphorus, layered heterostructures.
2. Property cheat sheet
| Material | E_g (eV) | Direct/Indirect | µ_e (cm²/V·s) | µ_h (cm²/V·s) | E_br (MV/cm) | k_th (W/m·K) | Typical use |
|---|---|---|---|---|---|---|---|
| Si | 1.12 | indirect | 1450 | 500 | 0.3 | 150 | CMOS, MEMS, c-Si PV |
| Ge | 0.66 | indirect | 3900 | 1900 | 0.1 | 60 | SiGe HBT, IR PD |
| GaAs | 1.42 | direct | 8500 | 400 | 0.4 | 55 | RF MMIC, NIR LED/laser |
| InP | 1.35 | direct | 5400 | 200 | 0.5 | 68 | telecom laser/PD, mm-wave HEMT |
| GaP | 2.26 | indirect | 250 | 150 | 1.0 | 110 | green/yellow LED (legacy) |
| GaN | 3.4 | direct | 1500 (2DEG ~2000) | 30 | 3.3 | 130 | power FET, RF HEMT, blue LED |
| AlN | 6.2 | direct | 300 | 14 | 12 | 285 | DUV LED, HEMT barrier |
| InN | 0.7 | direct | 3200 | 50 | 1.2 | 45 | InGaN active layer |
| InAs | 0.36 | direct | 33000 | 460 | 0.04 | 27 | high-µ HEMT channel, IR PD |
| InSb | 0.17 | direct | 77000 | 850 | 0.01 | 18 | LWIR PD, magnetic sensor |
| 4H-SiC | 3.26 | indirect | 1000 | 120 | 3.0 | 370–490 | 1200 V MOSFET, SBD |
| 6H-SiC | 3.0 | indirect | 400 | 90 | 2.4 | 350 | legacy SiC |
| 3C-SiC | 2.36 | indirect | 800 | 40 | 2.0 | 360 | research |
| β-Ga₂O₃ | 4.8 | indirect | 200 | low | 8 | 15 | >3 kV power (TRL ~5) |
| Diamond | 5.5 | indirect | 4500 | 3800 | 10 | 2200 | heat spreader, RF (research) |
| AlGaAs (x=0.3) | 1.80 | direct | 4000 | 200 | 0.6 | 14 | VCSEL DBR, HEMT barrier |
| InGaAs (x=0.53 on InP) | 0.74 | direct | 12000 | 300 | 0.2 | 5 | 1.55 µm PD, HBT |
| InGaAsP | 0.74–1.35 | direct | 5000 | 150 | 0.4 | 5 | DFB telecom laser |
| AlGaN (x=0.3) | 4.0 | direct | 300 | 10 | 5 | 25 | UV LED, HEMT barrier |
| InGaN (x=0.2) | 2.8 | direct | 500 | 25 | 2.5 | 25 | blue LED active layer |
| CdTe | 1.50 | direct | 1100 | 100 | 0.5 | 6 | thin-film PV |
| HgCdTe (x=0.3) | 0.28 | direct | 20000 | 600 | 0.05 | 2 | MWIR/LWIR detector |
| CdZnTe | 1.57 | direct | 1100 | 100 | 0.5 | 6 | X/γ detector, MCT substrate |
| ZnSe | 2.7 | direct | 530 | 16 | 1.4 | 19 | IR optic, legacy blue laser |
| ZnO | 3.37 | direct | 200 | 50 | 2.4 | 50 | TCO, varistor, piezoelectric |
| Graphene | 0 | (semimetal) | 200000+ | 200000+ | — | 5000 | RF, transparent electrode |
| MoS₂ (monolayer) | 1.8 | direct | 200 | 100 | 0.5 | 35 | 2D FET research |
| WSe₂ (monolayer) | 1.65 | direct | 250 | 250 | 0.4 | 30 | 2D ambipolar FET |
| hBN | 5.9 | indirect | — | — | 8 | 400 (in-plane) | 2D dielectric, substrate |
| Black P | 0.3 (bulk)–2.0 (mono) | direct | 1000 | 600 | 0.3 | 12 | IR PD, 2D FET research |
| Pentacene | ~2.2 | (organic) | 1–5 | 1 | — | 0.5 | OFET |
µ values are bulk room-temperature, undoped or lightly doped, single-crystal references. Actual device values vary with doping, scattering, and structure.
3. Silicon
The workhorse. Bandgap 1.12 eV (indirect) — too small for blue/visible emission, too large for SWIR (cuts off at 1.1 µm). Mobility 1450 cm²/V·s (e-), 500 cm²/V·s (h+). Breakdown field 0.3 MV/cm — limits Si power devices to ~900 V class with deep super-junction; SiC and GaN beat it above ~600 V.
Crystal growth:
- Czochralski (CZ): quartz crucible, B-doped or P-doped melt, pulled boule. ~95% of substrates. Contains 10¹⁷–10¹⁸ cm⁻³ oxygen from the crucible — beneficial (denuded zone gettering) for most CMOS but detrimental for high-voltage power and high-Q RF.
- Float zone (FZ): crucible-free; an RF coil melts a narrow zone that traverses a polysilicon rod. Oxygen <10¹⁵ cm⁻³, resistivity up to 10 kΩ·cm. Used for IGBT, thyristor, detectors, high-resistivity RF substrates.
Doping: B (p-type), P (n-type), As (n-type shallow source/drain, lower diffusivity than P), Sb (n-type heavy substrate, low diffusivity), Ga (rare p-type).
Wafer sizes: 300 mm (450 mm₁/₁₈ inch) standard since ~2002 in volume; 450 mm consortium (G450C, Intel/TSMC/Samsung/IBM/GlobalFoundries) wound down ~2017 — never reached production. 200 mm still huge for power, analog, MEMS; 150 mm and below for legacy and discretes.
Applications: all volume digital CMOS logic, DRAM/NAND/SRAM memory, image sensors (CIS), MEMS (inertial, microphone, pressure, DLP), photovoltaic c-Si monocrystalline and mc-Si multicrystalline (~95% of PV market 2025).
4. Germanium
Bandgap 0.66 eV indirect. Mobility ~3900 (e-) / 1900 (h+) cm²/V·s — about 2.7× and 3.8× Si respectively. Higher mobility but smaller bandgap → much higher intrinsic carrier density → leakage limits room-temperature MOSFET use.
First-generation transistors were Ge (Bardeen/Brattain/Shockley, Bell Labs 1947, Ge point-contact). Replaced by Si in the early 1960s for thermal stability.
Modern uses:
- SiGe HBT: strained Si₁₋ₓGeₓ base in heterojunction bipolar — IBM commercialized in 1990s (BiCMOS), now in TowerJazz, GlobalFoundries 8XP/9HP; f_T > 300 GHz, used in 60–80 GHz auto radar front ends and 5G FR2 transceivers.
- Ge photodiode: 1.55 µm cutoff; pin and APD for fiber optics — replacing InGaAs in some datacenter Si-photonics receivers because monolithic on Si.
- Ge-on-Si photonics: integrated detectors in 220 nm SOI Si-photonics PDK (GlobalFoundries 45CLO, IMEC, Intel).
- High-mobility channel: strained Ge or SiGe p-MOSFET channel for sub-7 nm nodes (Intel since 14 nm tri-gate).
5. Gallium Arsenide
Direct bandgap 1.42 eV. Electron mobility 8500 cm²/V·s (~6× Si). Lattice constant 5.6533 Å, matched to AlAs (5.6611 Å) → AlGaAs system is nearly lattice-matched everywhere.
Applications:
- RF / mm-wave power amplifiers: GaAs pHEMT, BiFET, HBT — the dominant cellular handset PA technology since 1990s. Skyworks, Qorvo, Murata, Broadcom front-end modules.
- LED / laser: GaAs/AlGaAs DH lasers at 780 nm (CD), 808 nm (pump), 850/980 nm (datacom VCSEL), 660 nm (DVD/red); AlGaInP LED red/orange.
- VCSEL: GaAs substrate with AlGaAs DBR mirrors — 850 nm datacom (Finisar/II-VI/Coherent, Lumentum, Broadcom), 940 nm illumination for ToF, 3D sensing in iPhone Face ID.
- PV: III-V multijunction (GaAs/InGaP/Ge) for space (Spectrolab, AzurSpace, SolAero) and CPV.
Crystal growth:
- LEC (Liquid Encapsulated Czochralski): B₂O₃ encapsulation; semi-insulating substrate for MMIC.
- VGF (Vertical Gradient Freeze): lower dislocation density (~1000/cm²); preferred for laser and LED substrates.
6. Indium Phosphide
Direct bandgap 1.35 eV. The substrate for long-haul fiber telecom: InGaAsP / InAlGaAs lasers and detectors lattice-matched to InP cover the 1.1–1.65 µm range that hits the silica fiber zero-dispersion (1.31 µm) and minimum-loss (1.55 µm) windows.
Applications:
- DFB / DBR lasers for long-haul C-band and L-band coherent transceivers (400G ZR/ZR+, 800G; vendors: Coherent, Cisco/Acacia, II-VI Coherent, Lumentum, NeoPhotonics now part of Lumentum).
- EAM (electro-absorption modulator) and MZM PICs.
- APD / pin photodiodes for receivers; InGaAs/InP APD at 1550 nm.
- InP HEMT / mHEMT for mm-wave LNAs in radio astronomy, satellite (f_T > 1 THz cited; NGAS, Diramics, IAF), and 110–170 GHz instrumentation.
Vendors: Sumitomo Electric, AXT, II-VI Coherent (acquired II-VI 2022, now branded Coherent Corp), JX Nippon Mining. Substrate diameters 2”, 3”, 4” production; 6” available.
7. Gallium Nitride
Direct bandgap 3.4 eV. Breakdown field ~3.3 MV/cm — 10× Si. Saturation drift velocity ~2.5 × 10⁷ cm/s. The lateral AlGaN/GaN HEMT relies on a polarization-induced 2DEG (2-dimensional electron gas) at the AlGaN/GaN heterointerface — no doping required, sheet density ~10¹³ cm⁻², mobility ~2000 cm²/V·s.
Three application domains:
Power electronics (lateral HEMT, normally-off enhancement-mode or cascode):
- 100 V, 200 V, 650 V, 900 V GaN-on-Si HEMT.
- Vendors: Infineon (acquired GaN Systems 2023, CoolGaN), Navitas, EPC, Transphorm, Power Integrations (acquired Odyssey 2017), Texas Instruments LMG series, STMicroelectronics MasterGaN.
- Use: phone fast chargers (65/100/140 W USB-PD GaN bricks), laptop adapters, server PSU LLC, EV onboard chargers, lidar pulser, class-D audio, RF wireless power.
RF / mm-wave (GaN-on-SiC HEMT):
- High power density (5–10 W/mm gate width), high f_T (40–250 GHz depending on Lg).
- Vendors: Wolfspeed (Cree RF, now Wolfspeed), Qorvo, NXP, Sumitomo Electric (SEDI), MACOM (acquired ST RF GaN-on-Si 2023), United Monolithic Semiconductors (UMS), Mitsubishi Electric.
- Use: 5G base-station Massive MIMO PAs (3.5–5 GHz), military S/X/Ku radar, electronic warfare, satcom SSPA.
Optoelectronic (InGaN/GaN heterostructures):
- Blue LED breakthrough: Shuji Nakamura at Nichia, 1993 — high-brightness InGaN/GaN blue → enabled white LED via blue + YAG:Ce phosphor. Nobel Prize 2014 (Akasaki, Amano, Nakamura).
- White lighting (Nichia, Osram, Cree LED→now Smart Global), display backlight, blue laser diode (405 nm Blu-ray, projector laser, automotive headlight), micro-LED (Apple Vision Pro, MicroLED display efforts at Samsung, AUO).
Substrate options:
- GaN-on-Si: cheapest, 150/200 mm, for power.
- GaN-on-SiC: thermal advantage, for RF.
- GaN-on-sapphire: standard for blue LED.
- Native bulk GaN: ammonothermal (Mitsubishi Chemical, SCIOCS) or HVPE (Sumitomo); 50–100 mm; for vertical-conduction power devices (research → early production).
8. Silicon Carbide
The most mature WBG power material. Polytypes:
- 4H-SiC: dominant. Bandgap 3.26 eV. Anisotropic mobility (higher along c-axis). All commercial power devices.
- 6H-SiC: 3.0 eV. Earlier polytype, lower mobility — largely displaced by 4H.
- 3C-SiC (cubic): 2.36 eV. Grown on Si — would enable cheaper integration but defect density still too high; research only.
Breakdown field ~3 MV/cm. Thermal conductivity 370–490 W/m·K — 3× Si — enables higher current density.
Devices:
- SiC Schottky diode (SBD): since ~2001 (Infineon ThinQ!). 600 V / 650 V / 1200 V / 1700 V; replaces Si fast-recovery diode in PFC and boost stages.
- SiC MOSFET: 1200 V and 1700 V volume; 3.3 kV, 6.5 kV, 10 kV emerging. Vendors: Wolfspeed (formerly Cree), Infineon CoolSiC, ROHM SCT3xxx, STMicroelectronics, Onsemi (acquired GTAT 2021 for SiC boule capacity), Mitsubishi Electric, Toshiba, BYD Semiconductor, SemiQ.
- SiC JFET / cascode: USCi (acquired by Qorvo, now part of UnitedSiC → Qorvo).
Applications:
- EV traction inverter (Tesla Model 3 was first volume SiC, 2017, using ST modules; now BYD, Hyundai E-GMP, Lucid, Mercedes EQS, GM Ultium — all SiC).
- DC fast charger.
- Solar / wind inverter.
- Server PSU.
- Rail traction (Mitsubishi N700S Shinkansen 3.3 kV SiC since 2020).
Crystal growth: PVT (physical vapor transport / modified Lely) — sublimation of SiC powder at ~2400 °C, deposition on a SiC seed crystal at the cooler end. Growth rate ~0.1–0.5 mm/h. Defect targets: micropipes (now <0.1/cm² production), basal plane dislocations (BPD), threading screw/edge.
Wafer sizes 2026: 150 mm production standard; 200 mm transition started 2022 (Wolfspeed Mohawk Valley fab opened April 2022, the first 200 mm SiC fab; STMicroelectronics 200 mm in Catania; Coherent II-VI 200 mm).
9. Gallium Oxide (β-Ga₂O₃)
Emerging UWBG. Bandgap 4.8 eV (β-phase monoclinic, the stable polytype). Baliga FOM ~3000× Si, ~4× SiC, ~3× GaN. Breakdown field ~8 MV/cm.
Pros: large bulk single-crystal substrates grow from the melt (EFG / Czochralski / float-zone) — much cheaper than SiC PVT in principle.
Cons: very low thermal conductivity (~15 W/m·K, 25× worse than SiC) → demands aggressive packaging / heat spreader. No usable p-type doping discovered → unipolar devices only (SBD, MOSFET); bipolar IGBT-class device not viable.
Vendors: Novel Crystal Technology (Japan), Flosfia (Japan, α-Ga₂O₃ on sapphire), Kyma, FLOSFIA. TRL ~5 in 2026. Targeted at >3 kV power.
10. Diamond
UWBG, 5.5 eV indirect. Breakdown theoretical ~10 MV/cm, thermal conductivity 2200 W/m·K (highest of any solid).
Synthesis: HPHT (yellow, jewelry-grade) and CVD (microwave plasma). Element Six (De Beers), II-VI / Coherent, Pure Diamond, SP3 Diamond Tech.
Electronic doping:
- B → p-type (acceptor ionization energy 0.37 eV — partial ionization at room temp).
- P → n-type (deep donor 0.6 eV — even more partial).
This makes diamond active devices hard. Surface-conductive H-terminated 2DHG FETs and δ-doped channels show progress but not yet commercial.
Practical use today is mostly passive: heat spreader for GaN-on-diamond MMIC (Akash Systems, RFHIC), diamond windows for high-power laser, diamond-substrate SAW. NV-center diamond is used for magnetometry/quantum sensing but is a different application class.
11. II-VI compounds
HgCdTe (Hg₁₋ₓCdₓTe, “MCT”): the dominant high-performance infrared detector. Bandgap tunable from 0 (HgTe, x=0) to 1.5 eV (CdTe, x=1) by composition x; bandgap E_g(x, T) ≈ −0.302 + 1.93x + 5.35×10⁻⁴ T(1−2x) − 0.81x² + 0.832x³ (Hansen formula). Choose x ≈ 0.21 for 10 µm LWIR, x ≈ 0.3 for 5 µm MWIR.
- Cooled (77 K Stirling cooler or thermoelectric) for high sensitivity.
- Vendors: Teledyne FLIR / Teledyne Imaging Sensors, Leonardo DRS, Lynred (Sofradir + Ulis merged 2019), AIM Infrarot, Raytheon Vision Systems, Sumitomo Electric.
- Grown by LPE (legacy) or MBE (modern, on CdZnTe substrate) — bulk CZT 50–80 mm; SWIR/MWIR also grown on Si (Teledyne H2RG, H4RG astronomy detectors — James Webb NIRCam uses HgCdTe-on-CZT).
CdTe: thin-film PV — First Solar (10+ GW/yr 2025 production, Series 7 modules). Lower lab efficiency than c-Si (~22%) but cheap per W and good high-temp performance.
CdZnTe (CZT): room-temperature X-ray / γ-ray detector (radiation portal monitors, medical CT, SPECT — GE, Spectrum Dynamics). Also the substrate for MBE-grown MCT.
ZnSe: mid-IR optic (10.6 µm CO₂ laser windows and lenses), short-lived blue laser ~1990s (lost to GaN).
ZnO: TCO (transparent conducting oxide, Al-doped AZO competes with ITO for TFT-LCD/OLED — supply-chain motivation since In is scarce); piezoelectric for SAW/FBAR; varistor (transient suppressor).
12. III-V ternary and quaternary alloys
Vegard’s law: lattice constant interpolates roughly linearly with composition. Bandgap interpolates with a bowing parameter. Used for bandgap engineering in heterostructure devices.
AlₓGa₁₋ₓAs: lattice-matched to GaAs across all x. Direct → indirect crossover at x ≈ 0.45 (1.98 eV). Used for AlGaAs/GaAs DH lasers, VCSEL DBR mirrors (alternating high/low Al pairs), AlGaAs/GaAs HEMT barrier (largely replaced by InGaAs/AlGaAs pHEMT).
Inₓ Ga₁₋ₓAs: lattice-matched to InP at x = 0.53, E_g = 0.74 eV → 1.65 µm photodetectors and SWIR cameras (Sony IMX990 SWIR sensor, Sensors Unlimited, Allied Vision, Xenics, IRnova). Pseudomorphic (strained) on GaAs for 980 nm pump lasers and pHEMT.
Inₓ Ga₁₋ₓAsₓ Pᵧ: quaternary on InP — independently tune lattice constant and bandgap. The telecom DFB / EML laser system at 1.31 / 1.49 / 1.55 µm.
AlₓGa₁₋ₓN: bandgap 3.4–6.2 eV → AlGaN/GaN HEMT barrier (x ≈ 0.2–0.3); deep-UV LED active region (UVC 265 nm AlₓGa₁₋ₓN at x ≈ 0.55 — surface disinfection, sterilization; vendors: LG Innotek, Bolb, Crystal IS / Asahi Kasei, Stanley Electric, Nichia).
Inₓ Ga₁₋ₓN: the visible LED active layer. x ≈ 0.2 for blue (450 nm), x ≈ 0.4 for green (525 nm). The “green gap” — efficiency dips between blue and red — is a well-known InGaN limitation.
InAlGaN: quaternary nitride, allows independent strain + bandgap; UV emitters, advanced HEMT barriers.
13. 2D and emerging materials
Graphene: zero gap, semimetal. Linear dispersion → Dirac fermions. Electron mobility >200,000 cm²/V·s in suspended; ~10,000 on SiO₂. IBM demonstrated 100 GHz graphene FET on SiC 2010 (Lin et al., Science 327, 662). Application reality 2026: not used as a logic transistor (no I_off — zero gap leaks). Used as transparent conductor (touchscreen, OLED), thermal interface, RF mixer, biosensor functionalization, anti-corrosion coating.
TMDC (transition metal dichalcogenides): MoS₂, MoSe₂, MoTe₂, WS₂, WSe₂, ReS₂. Layered structure — bulk indirect, monolayer direct. Bandgap ~1.0–2.0 eV. Mobility ~50–500 cm²/V·s. Research focus for ultra-scaled FET (sub-1 nm channel thickness, no short-channel effect). TSMC + imec roadmaps target TMDC channel for sub-A14 nodes (~2028+).
hBN (hexagonal boron nitride): large-gap insulator (5.9 eV). Used as gate dielectric and atomically flat substrate for 2D heterostructures — the “graphene-on-hBN” sandwich gives the highest reported 2D mobilities.
Black phosphorus: layered (phosphorene). Bulk gap 0.3 eV, monolayer ~2 eV. Strongly anisotropic. Air-sensitive. IR PD research.
Van der Waals heterostructures: arbitrary layer-by-layer stacking; twisted bilayer graphene (Cao et al. 2018, magic angle 1.1°) → flat-band superconductivity. Mostly fundamental physics through 2026.
14. Organic semiconductors
Charge transport via π-conjugated molecules; mobility orders of magnitude lower than crystalline inorganic — 0.1 to 10 cm²/V·s in best small-molecules.
Common molecules / polymers:
- Pentacene, rubrene: small-molecule p-type, OFET research; rubrene single crystal up to 40 cm²/V·s.
- P3HT (poly-3-hexylthiophene): OPV donor.
- PCBM (phenyl-C61-butyric acid methyl ester): OPV acceptor (fullerene derivative).
- Alq3 (tris(8-hydroxyquinolinato)aluminium): OLED ETL and green emitter.
- NPB, TPD: OLED HTL.
- Ir(ppv)₃, Ir(ppy)₃: phosphorescent OLED dopants (UDC / Universal Display patents).
- Polyfluorenes: blue polymer LED.
Commercial impact: OLED displays — Samsung Display (SDC) AMOLED phones since 2007 (Galaxy S original), LG Display white-OLED + color-filter TVs since 2013, Apple iPhone OLED since iPhone X (2017), all small/mid OLED through 2026 is organic small-molecule (vacuum thermal evaporation) — though QD-OLED (Samsung 2022+) and printed inkjet OLED (TCL/JOLED dissolved 2023) are alternatives.
OPV (organic photovoltaic) remains niche — best certified cell ~19% (2024), but module reliability/lifetime <10 yrs. Solliance / Heliatek deploy semi-transparent BIPV.
15. Substrate diameters / availability (2026)
| Material | Production diameter | Notes |
|---|---|---|
| Si CZ | 300 mm | volume; 200 mm for power/analog/MEMS |
| Si FZ | 200 mm | high-resistivity, power/RF |
| SiC 4H | 150 mm prod | 200 mm transition started 2022 (Wolfspeed Mohawk Valley) |
| GaAs LEC/VGF | 150 mm | semi-insulating for MMIC; 200 mm available |
| InP | 100 mm prod | 150 mm available (Sumitomo, AXT) |
| GaN bulk | 50 mm prod, 100 mm sample | ammonothermal/HVPE; 150 mm research |
| GaN-on-Si | 200 mm | for power HEMT |
| GaN-on-SiC | 100/150 mm | for RF HEMT |
| GaN-on-sapphire | 150/200 mm | for blue LED |
| Sapphire | 200 mm | LED substrate |
| β-Ga₂O₃ | 100 mm | Novel Crystal Tech, 150 mm research |
| Diamond CVD | ~50 mm mosaic | not single grain at that size |
| CdZnTe | 50–80 mm | MCT substrate / radiation detector |
| Ge | 200 mm | space PV, IR optics |
16. Selection heuristics
- Digital logic / standard CMOS → Si (no competitor at scale).
- High-mobility CMOS channel for sub-3 nm → Si with SiGe or Ge channels; TMDC speculative.
- Power, <650 V, low cost → Si super-junction MOSFET or IGBT.
- Power, 650 V class adapter / OBC → GaN-on-Si HEMT (Infineon CoolGaN / Navitas / EPC / Power Integrations).
- Power, 1200 V EV traction inverter → SiC MOSFET (Wolfspeed, Infineon CoolSiC, ROHM, ST).
- Power, >3 kV traction / grid → SiC IGBT-class or research Ga₂O₃.
- RF cellular handset PA → GaAs HBT or pHEMT.
- 5G base-station Massive MIMO PA → GaN-on-SiC HEMT (Wolfspeed, Qorvo, NXP).
- mm-wave LNA / radio astronomy → InP HEMT or InGaAs/InP mHEMT.
- LIDAR at 905 nm → Si SPAD / GaAs VCSEL emitter; at 1550 nm → InGaAs APD or SPAD on InP (eye-safe).
- MWIR thermal imager (3–5 µm) → HgCdTe MCT (cooled, high-performance) or InSb (cooled).
- LWIR thermal imager (8–14 µm) → HgCdTe MCT (cooled) or uncooled microbolometer (a-Si or VOₓ on Si MEMS — Lynred, FLIR, BAE, Seek; different technology — bolometer is thermal, not semiconductor-bandgap).
- Blue LED / lighting → InGaN-on-sapphire or InGaN-on-GaN.
- UV-C disinfection (265 nm) → AlGaN LED.
- Thin-film flexible PV → CdTe (First Solar — rigid glass) or CIGS (Solar Frontier exit 2022 → MiaSolé / Avancis) or perovskite (Oxford PV, Saule — TRL ramping).
- OLED display → small-molecule organic + phosphorescent dopants.
- Semiconductor qubit → Si (Intel Tunnel Falls, Quantum Motion); SiGe quantum dot (Delft/QuTech/Intel); GaAs/AlGaAs gate-defined (legacy, decoherence-limited). Note: superconducting qubits (IBM, Google, Rigetti) use Nb/Al on Si substrate — Si is just a low-loss substrate, not the active material.
17. Crystal growth methods
| Material | Method | Notes |
|---|---|---|
| Si | CZ, FZ | CZ dominant; 300 mm boules ~400 kg |
| Ge | CZ | for space PV substrate, IR optic |
| GaAs | LEC (semi-insulating), VGF (low EPD) | B₂O₃ encapsulation |
| InP | LEC, VGF | high-pressure |
| GaN bulk | HVPE, ammonothermal | slow; small diameter |
| GaN epi | MOCVD, MBE | on Si, SiC, sapphire, or bulk GaN |
| 4H-SiC | PVT (modified Lely) at ~2400 °C | ~0.1–0.5 mm/h; main yield-loss source for industry |
| 4H-SiC epi | CVD (chlorosilane / silane + propane) | on PVT seed wafer |
| Sapphire | Kyropoulos, EFG, Czochralski | LED substrate |
| CdZnTe | THM, Bridgman | for MCT substrate |
| HgCdTe epi | LPE (legacy), MBE (modern) | on CZT or Si |
| β-Ga₂O₃ | EFG, CZ, FZ | melt-grown — cost advantage in principle |
| Diamond | HPHT, CVD (microwave plasma) | ~50 mm single-grain ceiling |
| Si epi | CVD (DCS/TCS + H₂), MBE | for BiCMOS, image sensors |
| III-V epi | MOCVD (industry workhorse), MBE (precision) | TMGa/AsH₃, TMAl, TMIn, etc. |
18. Vendors / Foundries
Si wafer: Shin-Etsu Handotai, SUMCO, GlobalWafers (acquired Siltronic deal blocked 2022, but acquired Topsil 2016), Siltronic, SK Siltron (acquired DuPont SiC business 2020).
SiC wafer: Wolfspeed (the leader; spun off from Cree 2021), Coherent (formerly II-VI), Resonac (formerly Showa Denko, includes Showa-Denko SiC epi), SiCrystal (ROHM subsidiary), TankeBlue, Soitec (acquired GlobalWafers Epi 2023).
III-V wafer / epi: Sumitomo Electric (GaAs, InP, GaN), AXT (GaAs, InP, Ge), IQE (compound semi epi foundry — GaAs / InP / GaN / VCSEL), Wafer Technology, Atecom.
Compound semi foundries: TSMC has limited compound-semi (mostly Si), but Win Semiconductors (Taiwan, world’s largest GaAs MMIC foundry), AWSC, GCS (GlobalCommunication Semiconductors), UMS, OMMIC (closed 2023), MACOM.
Power-device makers: Infineon, STMicroelectronics, Onsemi, Texas Instruments, Wolfspeed, ROHM, Mitsubishi Electric, Toshiba, Fuji Electric, Hitachi, BYD Semiconductor (China), Sungrow (China), Yangzhou Yangjie.
Auto-grade power: Bosch (200 mm SiC fab Reutlingen 2024), Infineon (Dresden, Villach), STMicroelectronics (Catania), Wolfspeed (Mohawk Valley NY, Saarland Germany planned, paused 2024), Onsemi (acquired GTAT 2021 for SiC boules).
19. Cross-references
[[Engineering/semiconductor-devices]]— physical operation of diodes, BJT, MOSFET, HEMT, HBT, IGBT.[[Engineering/semiconductor-processing]]— fab unit processes: litho, etch, depo, implant, anneal, CMP, metallization, packaging.[[Engineering/Tier3/semiconductor-packages]]— package families: BGA, QFN, DIP, CSP, FOWLP, 2.5D/3D, automotive SiC modules (HybridPACK, Easy-PACK).[[Engineering/power-electronics]]— circuit topologies (buck/boost, LLC, totem-pole PFC, three-phase inverter) that consume these devices.[[Engineering/photonics]]— laser, LED, photodetector, fiber optics, integrated photonics — the optoelectronic side.[[Engineering/Tier3/ceramics-taxonomy]]— bulk + thin-film optical materials (glass, fluoride, IR materials including overlap with II-VI here).
20. Citations
- Sze, S. M.; Li, Y.; Ng, K. K. Physics of Semiconductor Devices, 4th ed. Wiley, 2021. The canonical reference.
- Pierret, R. F. Semiconductor Device Fundamentals. Addison-Wesley, 1996. Standard undergrad text.
- Baliga, B. J. Fundamentals of Power Semiconductor Devices, 2nd ed. Springer, 2019. Reference for power MOSFET/IGBT/SiC/GaN device physics and Baliga FOM.
- Nakamura, S.; Pearton, S.; Fasol, G. The Blue Laser Diode: The Complete Story, 2nd ed. Springer, 2000. Definitive InGaN/GaN history and device physics.
- Ioffe Institute NSM (New Semiconductor Materials) Archive —
https://www.ioffe.ru/SVA/NSM/— public property database for ~30 semiconductors. - SEMI standards M1–M58 — wafer dimensional, particle, flatness specs (M1 silicon wafer specs; M55 SiC; etc.).
- Properties of Group-IV, III-V and II-VI Semiconductors, S. Adachi, Wiley, 2005.
- Schubert, E. F. Light-Emitting Diodes, 3rd ed. Cambridge, 2018. LED physics including AlGaInP, InGaN, AlGaN systems.