Hot embossing of thick amorphous fluoropolymer for back end processing of infrared arrays

Abstract

A process is presented for patterning vias into thick amorphous fluoropolymer layers for a novel In bump fabrication process, achieved using a hot embossing technique. The technique uses a patterned Si stamp that employs a two-step etching process to obtain pillars with a controlled positive sidewall angle. After embossing with the Si stamp, vias are formed in amorphous fluoropolymer layers. A postembossing blanket reactive ion etch step is then used to remove excess fluoropolymer from the bottoms of the vias, exposing a Ni film. Successful electroplating of In bumps into vias initiated at the Ni layer is demonstrated, confirming complete removal of excess fluoropolymer.

Experimental and numerical study on deformation behavior of polyethylene terephthalate two-dimensional nanochannels during hot embossing process

“…Cyclic olefin copolymer (COC) replicas were embossed using an SU-8/Si mold with micro-features 100 μm wide and 80 μm deep [13]. Smooth via-arrays were imprinted into a thick fluoropolymer using a silicon stamp [14]. Various polymer microstructures with high aspect ratios were fabricated by hot embossing [15][16][17][18][19][20].…”