Delivery systems promise deposition evolution
Central reagent delivery systems could combine with high throughput reactors to overhaul existing III-V semiconductor manufacturing processes, according to MOCVD equipment maker Aixtron.
The company has deployed a Rohm and Haas VaporStation to deliver trimethylgallium into one of each of its Crius and Planetary reactors at its applications and demonstration center in Aachen, Germany.
According to Aixtron s technology vice-president Johannes Kaeppeler, replacing labor-intensive bubblers with centralized systems like VaporStation can increase the output from their MOCVD reactors.
“Future reactor generations will have significantly higher throughputs, which will increase metalorganic consumption,” Kaeppeler told compoundsemiconductor.net.
Raised metalorganic precursor consumption demands simplified supply, he says. VaporStation achieves this by delivering vapor from a central source cabinet in high-purity carrier gas via a series of pipes to up to 10 reactors. The cabinet can accommodate a 20 kg cylinder full of precursor.
“Customers will get an optimized maintenance procedure by reducing the bubbler exchange time, risk and effort,” Kaeppeler said.
Introduction of centralized delivery systems might also enable semiconductor manufacturers to outsource more aspects of precursor supply, Kaeppeler points out.
“Central metalorganic supply could become a service, which is very similar to the practice in the silicon industry,” he said.
Eliminating the need for bubblers also shrinks the size of Aixtron s equipment, removing the need for space to attach them and the thermostats used to regulate their temperature in the reactor cabinets. The German firm points out that this cuts down the expensive clean room space needed to accommodate the MOCVD systems.
Rohm and Haas precursor chemical manufacturing rival SAFC Hitech announced its own delivery system in 2008. However VaporStation has been available since 2004, and on that basis Aixtron judged this to be the best proven system.
Aixtron was able to use the VaporStation to produce GaN films with the same quality as bubblers, without the need for calibration runs that they normally demand.
Kaeppeler sees LED manufacturers "“ geographically dominated by Asian companies "“ as the most likely users of these systems. However he believes it will also be applicable for producing photovoltaic cells and more general III-V device manufacture.
