07/11 PSS Sapphire Wafer - Wet vs. Dry Etching
U.S. Department of Energy is expected to release a report stating that
in order to compete effectively with the fluorescent lighting market,
solid-state lighting manufacturers need to cut the cost per lumen
(currently at $18/klm) by 8x to $2.20/klm by 2015
efficiencies during the manufacturing process is a key method to drive
down costs. Larger-diameter sapphire wafers hold the promise of making
the manufacturing process significantly more efficient, but they also
present challenges to fabricators.
Patterned Sapphire Substrates (PSS)
serve a dual-purpose role in the LED industry. On the wafer supplier
side, they are money-makers. PSS wafers represent higher gross margins
than traditionally polished sapphire wafers. On the product development
side, PSS-based LEDs are more efficient, more effective light sources.
Dry etching is currently the most common method for producing PSS wafers. At this point, the techniques and technology for dry etching,
including the inductively coupled plasma (ICP) variant of dry etching
are commonplace. Though dry etching is slow and maintains limited
In comparison, the high-temperature wet etching process provides the dual advantages of being extremely fast and comparatively much cheaper than dry etching. Read More...