Particle issues during transport, or unsure which carrier fits which process? FOUP, SMIF Pod, PFA cassette — the names are familiar but choosing the right one for each process is where mistakes happen.
OHI Tech is an official CK Plastics partner supplying wafer carriers to major 300mm fabs in Korea. We have seen firsthand what selection mistakes lead to. Here are the criteria.
Bottom Line: Match the Carrier Material to Process Chemistry
Dry processes (etch, deposition): FOUP. Wet clean (HF, H₂SO₄): PFA cassette. Inter-fab long-distance shipping: FOSB.
Using standard PC-material FOUP in a wet chemical environment causes material degradation and particle contamination. Process environment and carrier material must match.
Wafer Carrier Type Comparison
| Type | Sealed | Primary Use | Material | Compatible Equipment |
|---|---|---|---|---|
| FOUP | Yes | 300mm dry processes | PC+ABS | EFEM, AMHS |
| FOSB | Yes | Inter-fab shipping | PC+ABS | External transport |
| SMIF Pod | Yes | 200mm legacy lines | PC | SMIF EFEM |
| PFA Cassette | Open | Wet clean, HF processes | PFA | Wet bench equipment |
Material Properties — Chemical Resistance Is Key
| Material | Chemical Resistance | Heat Resistance | Static | Primary Use |
|---|---|---|---|---|
| PC (Polycarbonate) | Medium | 120°C | Can charge | Standard FOUP |
| PEEK | High | 260°C | Low | High-temp processes |
| PFA (Fluororesin) | Very high | 260°C | Low | HF, sulfuric acid |
| ESD PC | Medium | 120°C | Dissipative | Static-sensitive processes |
5 Things to Confirm When Selecting a FOUP
1. Door type: robot arm compatibility (Entegris, Shin-Etsu, CK Plastics spec) 2. N₂ purge port: required if oxidation-sensitive process 3. Slot pitch: must match process tool boat pin spacing 4. RFID tag: MES wafer tracking integration 5. Cleaning durability: reuse cycles and cleaning method
CK Plastics FOUP — OHI Tech Supply
OHI Tech is the official Korean partner for CK Plastics, supplying the full lineup of FOUP, FOSB, and open cassettes — validated at major 300mm fabs in Korea. Rush orders and small quantities available.
FAQ
Q1. What is the difference between FOUP and FOSB? FOUP is for in-fab transport (AMHS, OHT). FOSB adds shock-absorbing pads and a reinforced locking mechanism for long-distance inter-fab shipping. Looks similar but FOSB is structurally more robust.
Q2. We still run 200mm legacy equipment. What carrier do we need? 200mm lines use SMIF Pod (standard) or open cassettes (wet processes). Share your equipment type and process conditions and we will recommend the right product.
Q3. What is the recommended FOUP cleaning interval and method? Generally every 500–1,000 cycles using IPA or DI water. Particle count testing after cleaning determines reuse eligibility. OHI Tech provides a cleaning procedure guide. Contact: jino.kim@ohitech.co.kr