Glass substrates for carrier and interposer applications and associated metrology solutions

Glass has many properties that make it an ideal substrate for important 3D-IC applications such as interposer substrates and glass carrier wafers. Critical material properties such as: ultra-high resistivity, low dielectric constant, ultra-low electrical loss and tailorable CTE, provide unique advantages. Forming processes such as the fusion forming process provide additional advantages around the ability to deliver low total thickness variation (TTV) without downstream grinding and polishing processes providing positive implications on both cost and performance. The ability to scale substrate sizes in size (450 mm wafers, panels) and thickness (down to 100 um) as well as panels provides tremendous advantages for the ability to scale for high volume manufacture. Just as important as being able to provide glass with these important attributes, is the ability to properly characterize them. We provide a summary highlighting the importance of the glass attributes in glass interposer and carrier applications, as well as implications of using the appropriate metrology solution to characterize them.