FFKM candidate grades by process, from public datasheets
This page lists candidate FFKM grades by semiconductor process, taken from what each manufacturer publishes. It is not an equivalence or interchange list: grades from different manufacturers are formulated and tested differently, and no grade is a drop-in replacement for another. Validate any candidate in your process.
Kalrez is a trademark of DuPont, Chemraz of Greene Tweed and Perlast of Precision Polymer Engineering; all trademarks belong to their owners. MST is a distributor and technical sourcing partner, not the manufacturer, and does not claim to be an authorized distributor of these brands.
Kalrez grades by process (DuPont)
| Process | Maximum service temperature in process | Suggested Kalrez grades |
|---|---|---|
| HDPCVD | 250 °C to 300 °C | 9100 / 9500 |
| PECVD / PEALD | 275 °C to 310 °C | 9600 |
| PECVD curing | 150 °C to 200 °C | 8705 (quartz window seal), 9500 (other locations) |
| SACVD / FCVD | 280 °C to 300 °C | 9500 / 9600 |
| Conductor (poly/metal) etch | 150 °C to 225 °C | 9100 / 9300 |
| Dielectric (oxide) etch | 100 °C to 180 °C | 9300 |
| Ash/strip | 180 °C to 250 °C | 9300 / 8002 |
DuPont asks users to consult its application guide or representative to assess fit for a specific application.
Chemraz semiconductor grades (Greene Tweed)
| Grade | Published temperature | Applications listed by Greene Tweed |
|---|---|---|
| Chemraz 657 | −18 °C to 280 °C, excursions to 300 °C | Dry wafer processing: endpoint windows, bell jar, valve, KF, lid, gas inlet, slit valve and chamber seals |
| Chemraz E38 | −20 °C to 260 °C | Dry wafer processing: bonded gate and chamber seals |
| Chemraz XPE | 280 °C maximum service | Chamber and slit valve seals, gas inlet/outlet, gate and isolator valves; O2 and CF4 plasma resistance |
| Chemraz 629 | −20 °C to 260 °C | Slit valve, lid, window, valve and gas inlet seals; hydrogen, oxygen and fluorine plasma |
Perlast high-temperature and plasma grades (PPE)
| Grade | Hardness, Shore A | Published temperature | PPE description |
|---|---|---|---|
| Perlast G7HA | 66 | −15 °C to +310 °C | High temperature, plasma resistant |
| Perlast G67P | 65 | −15 °C to +275 °C | High purity |
| Perlast G65HP | 65 | −15 °C to +260 °C | Radical plasma resistant |
| Perlast G75B | 85 | −15 °C to +325 °C | High temperature |
| Perlast G77X | 77 | −15 °C to +350 °C | High temperature |
How to use these lists
- Start from the process step and seal location, then shortlist grades each manufacturer suggests for it.
- Compare hardness and published temperature, remembering the test methods differ by manufacturer.
- Ask the manufacturer for plasma erosion, particle and outgassing data in conditions close to yours.
- Run a controlled trial on one chamber and compare seal life and particle counts before changing the whole fleet.
Frequently asked questions
Is Chemraz 657 equivalent to Kalrez 9100?
This page does not claim equivalence between any grades. Each is listed only because its manufacturer describes it for related processes. Validate any candidate in your own process.
Which Kalrez grade does DuPont suggest for ash/strip?
The DuPont plasma selector guide suggests Kalrez 9300 or 8002 for ash/strip, with a maximum service temperature in process of 180 °C to 250 °C.
Are these temperatures comparable across brands?
Not directly. Each manufacturer uses its own test method, and DuPont states its values are typical and not for specification.
Is MST an authorized distributor of these brands?
MST does not claim to be an authorized distributor of Kalrez, Chemraz or Perlast. MST is a distributor and technical sourcing partner and will state the supply channel on each quote.
Ask an engineer
Send the process step, seal location, current compound and the failure you see. MST, as distributor and technical sourcing partner, helps shortlist candidates to validate in your process.
Ask an engineerRelated pages
Sources
- DuPont Kalrez semiconductor plasma product selector guide (KZE-A40111-00-A0422)
- Greene Tweed, Chemraz FFKM overview
- Precision Polymer Engineering, high temperature elastomers (Perlast grade table)
Values are taken from the manufacturer documents above, checked 2026-10-23. Specifications can change; confirm against the current datasheet before ordering. MST is a distributor; products are made by the manufacturers named.