Full crystal growth flow
A general flow compiled from public data; actual steps and conditions vary by wafer maker.
Silicon wafers: crystal growth to polished wafer
Where chips begin: 11-nines polysilicon is melted and pulled (CZ) into a 300 mm, 2 m ingot, then sliced, lapped and polished flat. SiC wafers grow by PVT at fractions of a mm per hour — why they're costly.
34 steps (repeats counted once)
NewsAI is lifting demand for 300 mm wafers; SiC is moving from 6- to 8-inch for EVs and chargers.
One row per module; follow the blue arrows. Click a box for details.
- Polysilicon feedstockSteps 1–4
- 1Polysilicon intake11N purity
- 2Feedstock cleanAcid etch
- 3Dopant weighingBoron or phosphorus
- 4Load quartz crucible
- Crystal growthSteps 5–12
- 5Vacuum · argonPuller
- 6Melting~1420 °C
- 7Seed dipping
- 8NeckingClears dislocations
- 9ShoulderingDiameter grows to 300 mm
- 10Body growthMain ingot, about 2 m long
- 11Tailing
- 12Cool · remove ingot
- Ingot processingSteps 13–16
- 13Ingot checkResistivity · O₂ · defects
- 14Crop · section
- 15OD grinding
- 16Orientation notchNotch
- Slicing and shapingSteps 17–22
- 17Wire sawingDiamond wire
- 18Clean · demount
- 19Edge chamferPrevents chipping
- 20Double-side lappingLapping / Grinding
- 21EtchingRemoves damage
- 22Donor-killer annealDonor Killer
- PolishingSteps 23–25
- 23Double-side polishDSP
- 24Edge polishing
- 25Final polishOne side
- Clean & inspectSteps 26–30
- 26Final cleaningRCA clean
- 27Flatness
- 28Particles
- 29EpitaxyEpi only
- 30Epi checkEpi only
- ShippingSteps 31–34
- 31Outgoing QCLook · defects · data
- 32Load wafer shipping boxFOSB
- 33Vacuum dry packBag + desiccant
- 34To the fabWafer fab next
- ✓ Polished wafers to the fab
3 growth methods
| Method | How it grows | Wafer size | Used for |
|---|---|---|---|
| Czochralski (CZ) | Melt in a crucible; pull a rotating seed | Up to 300 mm | Most chips: logic, memory, power |
| Float zone (FZ) | No crucible; a coil melts a moving zone — very low oxygen | Mostly ≤200 mm | High-voltage power, sensors |
| PVT | SiC powder sublimes at 2,000 °C+ onto a seed | 150 mm, moving to 200 mm | SiC power devices: EVs, chargers |
FAQ
What is crystal growth?
Crystal growth melts high-purity polysilicon and slowly pulls a small seed crystal upward, so silicon atoms solidify in the seed's orientation and form a whole single-crystal ingot with uniform crystal direction. Sliced and polished, the ingot becomes wafers, the raw material for every chip.
Is crystal growth part of front-end semiconductor processing?
No. Front-end processing means the fab building circuits on wafers; crystal growth is the materials process that makes the wafer itself, handled by wafer makers and sitting upstream in the supply chain.
Why does crystal growth start with "necking"?
When the seed first touches the molten silicon, thermal shock creates dislocations (misaligned atoms) in the crystal. Pulling the seed into a neck just a few millimeters thick lets the dislocations escape out the sides, so what grows after the diameter widens is a perfect, dislocation-free single crystal.
How many wafers can one 300 mm ingot yield?
A 300 mm ingot is about two meters long. After removing the cone-shaped ends and out-of-spec sections, and accounting for wafer thickness and diamond wire kerf loss, one ingot yields roughly a thousand wafers.
What's the difference between polished wafers and epi wafers?
Polished wafers ship directly after slicing, lapping, and polishing. Epi wafers have an extra layer of single-crystal silicon a few microns thick grown on a polished wafer, allowing more precise control of that layer's doping and defects; they're used mostly for power devices and some logic chips.
Why are silicon carbide (SiC) wafers so expensive?
SiC can't be melted and pulled like silicon. It's grown by physical vapor transport (PVT) above about 2,000 °C, with SiC vapor slowly depositing into a crystal at just a few tenths of a millimeter per hour, so each run yields a boule only a few centimeters tall. The material is also very hard, making slicing and grinding slower than silicon, so yields are low and costs high.
Sag trips on pullers and saws?
An ingot takes days; one stop can scrap it. The VSP guards controls, switching in 1 ms. Tell us your setup.
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