The latest promising optoelectronic devices require complex 3D structures. In this study, optical grayscale microlenses and multi-height structures are etched into a polymer layer in a Capacitively Coupled Plasma reactor (CCP).
Etching can cause profile deformation and surface roughness, which may affect device performances. A parametric study is conducted to investigate 3D etching mechanisms.
We observed strong shape modulation by varying plasma parameters. Increasing chamber pressure, or decreasing High Frequency power, show similar tendencies, going from a rounded to a conic profile. Additional experiments suggest that 3D etching mechanisms rely on complex passivation processes and ion bombardment effects.
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