As SiC and GaN establish themselves as the mainstream in industrial and automotive power semiconductors, materials science is already advancing research and development on next-generation materials. Three candidate families are drawing significant attention: Ga₂O₃ (gallium oxide), GaN on GaN (native-substrate GaN), and diamond semiconductors, each targeting volume production in the 2030s. For designers and procurement professionals, anticipating the technology transition timeline is the key to competitive advantage.
Current Generation: Characteristics and Market Trends of SiC and GaN
GaN outperforms SiC on Baliga's figure of merit and excels at low-loss operation in high-frequency, high-voltage applications. The GaN power semiconductor market is growing at a CAGR of 49% from 2022 to 2028; projections show an average annual growth rate of 20.83% from 2025 to 2035, reaching a market size of $106.3 billion by 2035. AI server power supplies, 800 V EV architectures, and 5G communication infrastructure are the primary demand drivers. NVIDIA has announced its transition to the 800 V high-voltage power era, positioning GaN as a critical enabling technology.
SiC's high breakdown field strength and low on-resistance (Ron) have brought it into volume production for EV traction inverters. As the transition to 8-inch wafers progresses, device costs are estimated to fall 20–35% over the long term.
GaN on GaN — Advantages and Challenges of Native Substrates
GaN on Si (GaN on silicon substrate) keeps volume production costs low, but the high dislocation density caused by lattice mismatch with the substrate affects reliability. GaN on GaN (GaN on GaN substrate) substantially reduces dislocation density, making it easier to overcome reliability issues such as charge trapping and gate instability. The short-circuit withstand time (SCWT) of GaN on Si — well below 1 μs and far shorter than silicon IGBTs — is also expected to be less constrained on native substrates.
GaN single-crystal substrate manufacturing costs remain high, and progress toward larger diameters has been slow, with 2–4 inches remaining the norm today. Achieving high-quality, large-diameter, low-cost GaN substrates is the primary technical barrier to volume adoption; Sumitomo Electric and Mitsubishi Chemical are among the companies developing volume production technologies. Automotive manufacturers developing AEC-Q101-qualified GaN on Si devices are targeting integration into 2027–2028 volume production models, with migration to native substrates as a subsequent option.
Ga₂O₃ (Gallium Oxide) — A Leading Candidate for Ultra-High Voltage
β-Ga₂O₃ has a bandgap of approximately 4.8 eV, substantially exceeding SiC (3.3 eV) and GaN (3.4 eV), and its breakdown field strength reaches approximately three to four times that of SiC. In theory, it offers outstanding performance for ultra-high-voltage applications above 10 kV — power grids, railways, and large industrial equipment.
Two major challenges currently impede volume production: difficulty in p-type doping and low thermal conductivity (approximately one-quarter that of SiC). Substrate supply businesses, including Novel Crystal Technology (Japan), are beginning to emerge, and partial commercialization for industrial applications in the early 2030s is considered a realistic outlook.
Diamond Semiconductors — Distance to Practical Use
Diamond has the highest bandgap (5.5 eV) of all semiconductor materials, the highest thermal conductivity (approximately five times that of SiC), and high carrier mobility, enabling operation in extreme environments — ultra-high temperatures, space, and defense. AIST and Sumitomo Electric are advancing prototype demonstrations, but the difficulty and cost of synthesizing large-diameter single crystals means practical volume production devices are not expected before the late 2030s to 2040s.
Technology Maturity and Volume Production Outlook
| Material | Bandgap | Current Maturity | Industrial Volume Production | Primary Applications |
|---|---|---|---|---|
| SiC | 3.3 eV | Volume mainstream | Now onward | EVs, industrial inverters |
| GaN on Si | 3.4 eV | Volume ramp | Now–2028 | OBC, AI data centers |
| GaN on GaN | 3.4 eV | Prototype–early volume | 2028–2033 | High-reliability, high-frequency |
| Ga₂O₃ | 4.8 eV | Research–prototype | 2030–2035 | Ultra-high voltage, power grids |
| Diamond | 5.5 eV | Basic research | 2035 onward | Ultra-high temperature, space, defense |
Implications for Designers and Procurement Professionals
Design Decisions for 2026–2028
SiC and GaN on Si remain the primary options. For 800 V EV applications, prioritize SiC; for compact high-frequency use cases, prioritize GaN on Si. GaN on GaN adoption is realistic from 2028 onward, once sufficient reliability validation data has accumulated.
Tracking Ga₂O₃ Developments
Engineers working on inverter designs requiring voltages above 10 kV should begin tracking the technology developments and substrate supply chains of domestic and international Ga₂O₃ startups now. The aim is to position these materials for integration into design roadmaps in the 2030s.
Long-Term Supply Chain Diversification
Companies with concentrated reliance on leading SiC wafer suppliers should map a five-year plan to restructure their supply chain in anticipation of transitions to Ga₂O₃ and 200 mm SiC.