Alignment marks and applications thereof, readout circuit chip and applications thereof

Abstract

This invention relates to an alignment mark and its application, and a readout circuit chip and its application. The alignment mark includes: a first alignment mark disposed on the front and / or back of a substrate, and a second alignment mark disposed on a photomask and matching the shape of the first alignment mark. The first alignment mark includes a photolithographic area, and the second alignment mark includes a first photolithographic area and a second photolithographic area. The first and second photolithographic areas are spaced apart. A light-transmitting material is disposed in the photolithographic area and the first photolithographic area to form a light-transmitting area. During photolithography, the first alignment mark corresponds to the second alignment mark, so that indium pillar holes are formed on the substrate. The first indium pillar and the second indium pillar are formed by vapor deposition in the indium pillar hole area. The readout circuit chip includes a readout circuit disposed on the substrate, a pad, the first indium pillar, and the second indium pillar. The readout circuit chip is applied to an infrared detector, and the readout circuit is flip-chip interconnected with a second chip through a second indium ball formed by the second indium pillar.

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