Patterned Sapphire Substrate AFM image

Patterned Sapphire Substrate

Patterned Sapphire Substrates (PSS) are critically used in HB-LED manufacturing to improve light output and overall device efficiency, reducing $/lumen.  A PSS is typically a sapphire wafer into which a periodic patterned has been etched.  These pattern structures can vary in shape from conical, hemispherical, pyramidal or other similar structure which can be challenging for optical techniques to adjust.  These structures are used to change the angle of outgoing photons reducing total internal reflection and thus increasing efficiency.  The Edge-PSS AFM provides the necessary metrology to control the PSS fabrication process including feature height, width, and angle while also providing a full 3D profile.  PSS suppliers and LED manufactures will continue to shrink the pitch and dimensions of the embedded structures to gain ever important efficiency and the Edge-PSS is aptly capable to meet these demands.