From Reactor Operation to Process Understanding

CVD diamond deposition may continue for many hours or days. Final wafer measurements show the outcome, but they do not always reveal when temperature drift, plasma asymmetry or thickness nonuniformity developed. Carat Systems is integrating reactor control, long-run data collection and spatial optical diagnostics to help researchers and manufacturers evaluate the complete deposition process rather than only the finished sample.

Configuration note: Available measurements, scan modes, retrofit scope and automation level depend on the reactor, sensors and process requirements. Carat reviews each integration before defining the project scope.

Current Capability Areas

The platform is structured around three practical needs: recording the run, measuring spatial behavior and modernizing controls where the existing architecture limits development.

Long-Run Process Monitoring

Time-synchronized process records can support troubleshooting, run comparison and process transfer.

Power, pressure, gas-flow and temperature trends
Recipe and run identification
Alarm, warning and permissive history
Configurable data logging and export
Comparison of operating behavior between runs
Remote diagnostic review where appropriate

Spatial Process Diagnostics

Carat already uses mapped final-wafer measurements to quantify thickness uniformity. Automated scanning is being developed to connect those final results with spatial behavior observed during the deposition process.

Single-point, X-line, Y-line and XY-raster scan modes
Spatial substrate-temperature mapping
Early reflectance or thickness mapping where supported
Growth-rate and time-dependent map development
Optical-emission mapping with compatible instruments
Correlation with process conditions and final wafer data

Existing wafer result: A published 100 mm-class, nine-location thickness map reported a mean thickness of 1.014 µm and 13.2% nonuniformity. View the thickness map and analysis.

Control & Instrument Integration

Carat can evaluate new controls or instrument integration for selected CVD research and production systems.

Human-machine interface and recipe functions
Data acquisition and device communication
Pyrometer, spectrometer and OES integration
Scanner and stage-motion integration
Alarm and permissive restructuring
Modernization of selected legacy control systems

Applications in Diamond Process Development

Control and metrology are most useful when tied to a specific growth problem. Potential applications include:

100 mm wafer-scale uniformity development
Evaluation of high-power processing on thin wafers
Vacuum-chuck and substrate thermal-contact studies
Bias-enhanced nucleation and early interface development
Long-duration thick-film growth
Reactor geometry and plasma-position optimization
Correlation of in-situ data with thickness, Raman and surface measurements

Project Scope

A project may include software, controls, instrumentation, scanner hardware, process testing or a defined combination of these elements.

New Carat reactor configuration
Upgrade of an existing Carat system
Process-development work performed at Carat
Selected retrofit or modernization projects
Data-review and troubleshooting support

A technical review is required before Carat commits to compatibility, safety-related control changes or performance outcomes on third-party and legacy equipment.

A Diamond-Specific Development Platform

Generic HMI or SCADA programming is not the central offering. The value comes from combining control, data logging and optical measurements with practical knowledge of microwave plasma CVD diamond growth. This allows the system architecture and recorded data to be organized around process questions such as wafer temperature, growth-rate evolution, plasma symmetry, nucleation behavior and long-run stability.

The objective is to reduce dependence on isolated end-of-run measurements and make process-development decisions using a more complete record of the deposition.

Flexible Implementation

The control and metrology package can be configured around the customer's reactor and development priorities.

Monitoring-only upgrades
Scanner and sensor integration
New-system control configuration
Defined process-development programs
Selected modernization projects

Final functions, interfaces and deliverables are established during engineering review.

Selected Legacy System Support

Carat may provide limited control modifications or modernization for selected legacy Astex, Carat and customer-built CVD systems. Work is accepted only after review of the existing control architecture, available documentation, hardware condition and requested changes.

Possible work may include set-point or recipe changes, revised alarms, data logging, new instrument integration or migration to a newer control platform. Legacy Paragon support is treated as a specialized service rather than the primary focus of this page.

CVD Diamond Reactor Control, Monitoring & Metrology