Veeco Develops a Tool to Reduce Epitaxy Costs and Increase LED
Brightness With the help of DOE funding, Veeco is working on
reducing epitaxy costs and increasing LED efficiency by
developing a physical vapor deposition (PVD) tool for depositing
aluminum nitride buffer layers on LED substrates. PVD, also
known as "sputtering," is an alternative to metal-organic
chemical vapor deposition (MOCVD). PVD is a purely physical
process that involves plasma sputter bombardment rather than a
chemical reaction at the surface to be coated, as in MOCVD. PVD
can be used on both sapphire and silicon substrates. It could be
especially beneficial with silicon, which at the present time
poses more problems as an epitaxy substrate than does the widely
used but more expensive sapphire. A "greener" process than
MOCVD, PVD does not use any toxic chemicals. It also has the
potential to use fewer materials. In addition, PVD has the
potential for reducing the defect density, which could lead to
higher-brightness LEDs. The objectives o