In-process vacuum monitor for leak detection

Many vacuum-related processes operate at high/ultra-high vacuum levels and the quadrupole mass spectrometer is routinely used for measurement of vacuum quality, for leak detection and for process monitoring.

Such processes involving thin-film preparation and etching can however produce an unfavourable mass spectrometer environment due to the potential condensation of both conducting and insulating films.

The Hiden HALO 201 MBE was conceived specifically for operating in this latter environment, initially for application to the molecular beam epitaxy process.

Mounting on a standard DN-40-CF Conflattype flange, the probe’s sensitive ionisation region is totally shrouded to inhibit random surface deposition.

Construction materials are restricted to stainless steel, molybdenum and alumina to minimise potential process contamination in aggressive environments.

The unit has a mass range of 1-200 amu for measurement of all common gases and contaminants, with operating modes for vacuum species identification, leak detection, process trend analysis.

User-assignable I/O’s enable simultaneous operation for identification of process irregularities and for vacuum protection.

The MASsoft Professional PC control software is intuitive and multilevel offering simple operation yet incorporating a broad range of advanced features for the experienced vacuum user.

Features include:

• Template-driven quick-start operation
• Multiple RGA operation over Ethernet link
• Mixed mode scanning
• Trend analysis extraction from multiple sequential mass range scans
• Auto mass alignment

The PC interface includes TCP/IP, USB and RS232 communication links, multi-protocol RS485 links for external devices such as temperature and process pressure, 5 channel TTL for process control auto start/stop triggering.