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17 October 2008


Lorex launches dopant mixing system with piezo-control

Lorex Industries Inc of Poughkeepsie, NY, USA has launched a Dopant Mixing System (DMS) that, it claims, better fulfills the needs of silicon and compound semiconductor manufacturing for improved doping process control. Pre-mix gases that can be used include arsine, di-borane, di-silane, germane, methylsilane, phosphine, and silane.

Starting with a dopant pre-mix concentration of 1-10% at the inlet, the Piezocon DMS uses the concentration measurement and control capability of Lorex’s Piezocon sensor to control the dilution of the pre-mix down to a lower adjustable concentration of 50-200ppm, with what is claimed to be both excellent concentration control (±0.5ppm at 50ppm and ±1ppm at 200ppm) and reproducibility, making it immune to cylinder-to-cylinder shifts in inlet pre-mix concentration or to drifts in concentration over the life of the cylinder.

As well as providing improved doping control, by starting from a higher pre-mix concentration level the DMS allows the frequency of pre-mix tank exchange to be reduced, virtually eliminating follow-on time-consuming tool re-qualification and significantly cutting the associated production cost.