BharatNotes What is Semiconductor Fabrication (Fab)?
Semiconductor fabrication is the process of building integrated circuits (chips) on a wafer of ultra-pure single-crystal silicon. Electronic circuits are created gradually through repeated cycles of photolithography (patterning the wafer using light-sensitive photoresist and a mask), etching, thin-film deposition, thermal oxidation and ion implantation. A complex chip may pass through the photolithographic cycle dozens of times. The word "fab" also denotes the plant itself — a facility demanding ISO Class 1-5 cleanrooms, vast quantities of ultra-pure water and power, and round-the-clock operation. A leading-edge fab can cost well over USD 15 billion.
Process Nodes and Why Size Matters
A fab's capability is described by its process node, measured in nanometres (nm). A smaller node means smaller, more densely packed transistors, giving better performance and lower power consumption. Cutting-edge nodes (5 nm, 3 nm and below) require Extreme Ultraviolet (EUV) lithography (13.5 nm wavelength), whereas older lines use Deep Ultraviolet (DUV, 193 nm) light. India's approved fab (Tata-Powerchip, Dholera) targets the 28 nm mature node — strategically chosen because such nodes dominate automotive, industrial and consumer demand.
Fab vs ATMP/OSAT
The chip value chain separates "front-end" fabrication from "back-end" packaging:
| Stage | What it does | Capital/skill profile |
|---|---|---|
| Fab (front-end) | Etches circuits onto the wafer | Extremely capital-intensive (USD 10-20 bn+), high-tech |
| ATMP / OSAT (back-end) | Assembly, Testing, Marking, Packaging of finished wafers | More labour-intensive, lower cost of entry |
ATMP/OSAT is where India has its strongest near-term opportunity, as packaging is a less concentrated, less capital-heavy segment.
India's Semiconductor Push
The India Semiconductor Mission (ISM) was approved by the Union Cabinet in December 2021 under the ₹76,000 crore Semicon India programme, offering fiscal support of up to 50% of project cost for fabs, compound-semiconductor units, ATMP/OSAT facilities and design.
Key milestones (as of late 2025):
- 10 projects approved, cumulative investment ~₹1.60 lakh crore, across 6 states.
- Tata Electronics-Powerchip 28 nm fab, Dholera (Gujarat) — ~₹91,000 crore, ~50,000 wafers/month.
- Micron ATMP facility, Sanand (Gujarat) — over ₹22,500 crore.
- VIKRAM3201, India's first fully Make-in-India 32-bit microprocessor, fabricated at the 180 nm CMOS fab of the Semiconductor Laboratory (SCL), Mohali with ISRO, was presented to the PM at Semicon India 2025.
Significance and Challenges
Chips are strategic infrastructure; over-reliance on imports (~90-95% of demand, roughly USD 24 billion/year) is a supply-chain and national-security vulnerability. Domestic fabs promise resilience, jobs and high-tech capability. Challenges remain steep: enormous capital needs, scarce ultra-pure water and uninterrupted power, dependence on imported equipment (EUV) and chemicals, and a global talent crunch.
