MOCVD & LED Process Gas
MOCVD tools switch rapidly between precursor and purge flows, often at elevated temperature and under vacuum. The valves on these lines must have low dead volume, fast response and no cavities that retain a previous precursor.
Valonix three-way switching valves, metering valves and UHP diaphragm valves are used on metal-organic source lines, hydride delivery, ammonia and hydrogen carrier legs.
Fast, clean switching
A three-way diaphragm valve replaces a tee plus two valves on a run/vent leg, cutting dead volume and shortening the purge needed between layers. That directly affects interface sharpness in epitaxial growth.
- Three-port run/vent switching
- Low internal volume
- Short purge between growth steps
Precursor and hydride handling
Metal-organic precursors and hydrides require strictly compatible wetted materials and leak-tight isolation. Metering valves with Cv 0.019 set low precursor flows; normally closed pneumatic valves protect the safe state on hydride lines.
- Fine metering stems for precursor flows
- Normally closed hydride isolation
- Material compatibility declared per gas
Vacuum and temperature
MOCVD lines cycle between vacuum and positive pressure, and some are heated. Bellows sealed valves are specified where temperature or aggressive chemistry makes a diaphragm valve unsuitable.
- Vacuum cycling capability
- Heated line considerations
- Bellows valves for aggressive/hot services
Recommended valve families
Three-Way Diaphragm Valves
Three-port UHP diaphragm valves for process/purge/vent switching in specialty gas panels
Metering & Needle Valves
High purity metering and needle valves for precise specialty gas flow control
Bellows Sealed Valves
Bellows sealed valves for toxic, corrosive and high temperature specialty gases
Frequently Asked Questions
Why use a three-way valve on a MOCVD run/vent leg?
It removes the tee and extra joints, cutting dead volume and the purge time between epitaxial layers.
Which valve sets low precursor flow?
A fine metering valve with Cv around 0.019 gives the resolution needed for low precursor flows.