News Article
Feature: Photoresist for on-wafer 3D features
The increasing use of via holes and other 3D features is posing a challenge to conventional resist technologies. Henry Hendriks, James Tajadod and John Klocke describe a solution.
For most wafer lithography process steps, spin-coated liquid photoresist (LPR) is utilized, and for wafer surfaces with little topography this results in a layer of fairly uniform thickness. However, because the uniformity of the spin-coated LPR layer depends heavily on the topography of the wafer surface and the properties of the photoresist (viscosity and vapor pressure), this technology can fail dramatically in the coverage of highly elevated or deeply etched structures.
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