Extended electrode for photovoltaic tellurium-cadmium-mercury probe and preparation method for extended electrode

Abstract

The invention discloses an extended electrode for a photovoltaic tellurium-cadmium-mercury probe and a preparation method for the extended electrode. The electrode is an extended electrode, and the electrode of a pn junction injection area is extended to the surface of a composite passivation layer of a non-injection area. The method comprises the following steps of: performing photoetching by adopting a negative photoresist to obtain a photoresist mesa with big top and small bottom, growing the composite passivation layer with slowly variable thickness around the pn junction injection area of a tellurium-cadmium-mercury chip by using the pattern shadow effect of the photoresist mesa when a film is grown, growing a layer of electrode, and extending the electrode to a position far away from the pn junction injection area. The electrode prepared by using the method can ensure that the electrode in the pn junction injection area is completely electrically communicated with the electrode on the surface of the composite passivation layer; and meanwhile, an indium post for face-down bonding interconnection is prepared at the extended position of the electrode and far away from the pn junction injection area, so that a pressure bearing point is far away from the pn junction during face-down bonding interconnection and the performance of a device is improved.

Description

technical field [0001] The invention relates to an electrode film preparation technology for a photovoltaic type mercury cadmium telluride detector, in particular to an extended electrode and a preparation method for a photovoltaic type mercury cadmium telluride detector. Background technique [0002] Infrared focal plane detector is an imaging sensor that realizes infrared information acquisition and information processing at the same time, and it has a wide range of applications in military and civilian fields. Mercury cadmium telluride infrared focal plane detector is currently the most rapidly developing and most demanded detector in the world. It has developed from the first generation to the third generation focal plane characterized by large array, miniaturization, multicolor and integration. . [0003] Since the long-wave 8-14 micron is the window for surface radiation detection, it is in the CO2 spectral absorption region, and it is the main area for thermal imagin...

AI Technical Summary

Problems solved by technology

If the indium column is directly grown on the photosensitive element of the chip, the stress point of the flip soldering pressure will directly act on the pn junction of the photosensitive element, and various material defects are likely to be caused at the stressed position. The long-wave detector has a small band gap and is easier to form Leakage current, which makes the dark current of the device too large and reduces the performance of the device

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