SiC epitaxial growth

Until December 2025, India produced not one commercial silicon carbide epitaxial wafer. It imported over 90% of its semiconductor components, and every SiC epi-wafer entered from abroad.

That gap matters because SiC epitaxial wafers sit beneath the power electronics of the next decade — 800V electric vehicle powertrains, renewable energy inverters, 5G infrastructure. An epitaxial wafer is a single-crystal silicon carbide layer, a few micrometres thick, grown on a polished SiC substrate. The thin layer defines the device's electrical character.

The growth is genuinely hard. A workable process runs in two stages: a slow nucleation layer, deposited at 0.5–2 micrometres per hour and only nanometres thick, seeds the surface defect landscape before faster bulk growth builds the functional layer. The point is to decouple where defects form from where the device lives. Threading and basal-plane dislocations that survive this control device yield and reliability directly. Scaling the wafer diameter — 6-inch to 8-inch and beyond — cuts cost per wafer but reintroduces every quality problem at larger area. Wolfspeed announced a 300mm SiC wafer in January 2026; the frontier keeps moving.

India's climb is now visible on two tracks. In November 2024, DRDO's Solid State Physics Laboratory announced indigenous 4-inch SiC wafers and GaN-on-SiC devices, with production of GaN/SiC MMICs established at GAETEC in Hyderabad. This is lab-scale prototype work, not volume manufacturing. On the commercial track, RIR Power Electronics — listed on the Bombay Stock Exchange — is building India's first commercial SiC facility in Bhubaneswar with a ₹618 crore Odisha subsidy approved in August 2025, targeting Phase-1 epitaxy wafer production by December 2025 and MOSFETs and diodes from 3.3kV to 20kV in later phases. SiCSem, an Archean subsidiary, broke ground in Bhubaneswar in November 2025 with UK partner Clas-SiC. Indichip signed a ₹14,000 crore MOU with Andhra Pradesh in January 2025, with Japanese technology transfer from Yitoa Micro Technology.

The gap persists because the capability is a stack, not a step. Substrate crystal quality, CVD reactor control, precursor chemistry, defect characterisation, doping uniformity, device fabrication, and automotive qualification each gate the next. Roughly five firms — Wolfspeed, Coherent, STMicroelectronics, ROHM, SK Siltron — control about half of global capacity as of 2025; only around ten nations possess the process.

Closing it means clearing the automotive qualification cycle — 18–24 months, locked to a specific wafer diameter — that separates a working wafer from a saleable one. India's path runs through that gate.