Large area microwave plasma CVD diamond scale up
Carat Systems develops high power 915 MHz microwave plasma CVD platforms for large area diamond coating, seed production, and process scale up beyond conventional 2.45 GHz reactor sizes.
915 MHz high power microwave plasma CVD platform for large area diamond coating development.
Why 915 MHz matters for large area diamond growth
Scaling CVD diamond from 100 mm toward 150 mm, 200 mm, and 300 mm class substrates is not simply a matter of increasing methane flow or deposition time. At larger diameters, the limiting factors become plasma footprint, field structure, substrate coupling, heat removal, edge effects, and film stress.
A 915 MHz high power platform provides a path to larger plasma volumes and higher total microwave power, enabling development programs where 2.45 GHz systems become constrained by plasma size and thermal uniformity.
Large plasma footprint
Supports development toward 150 mm to 300 mm class coating areas.
High total power
Enables process windows that are difficult to access with smaller 2.45 GHz platforms.
Scale up engineering
Focuses on coupling, thermal management, fixturing, and uniformity instead of chemistry alone.
Target applications
- Large area polycrystalline CVD diamond wafers
- Diamond on silicon thermal spreaders
- High power electronics thermal management
- Optical and electronic grade diamond scale up
- Seed production for single crystal diamond growth
- Custom large area coating development
Development approach
- Define substrate size, thickness target, and film quality requirements
- Evaluate thermal coupling, fixture design, and edge control
- Develop uniformity and bow targets at smaller scale first
- Transition from 2.45 GHz process knowledge into 915 MHz scale up
- Use sample coating and process development to reduce scale up risk
De-risking 300 mm class diamond coating
Carat's scale up work indicates that larger area diamond growth becomes increasingly sensitive to thermal engineering, edge effects, field structure, and substrate coupling. The 915 MHz platform is intended for programs where a larger plasma footprint and higher total power are required to support a credible path toward 300 mm class diamond coating.
- 100 mm, 10 kW, 2.45 GHz operation supports stable and reproducible diamond growth.
- 150 mm to 200 mm scale introduces stronger thermal and coupling constraints.
- 915 MHz, approximately 100 kW operation has demonstrated a plasma footprint relevant to 300 mm class development.
Large plasma area for simultaneous diamond seed production and scale up development.
Side-opening chamber design for cleaning, service access, and large area process development.