Manufacturing method of thermopile device with suspension bridge structure

Abstract

The invention relates to a manufacturing method of a thermopile device with a suspension bridge structure. The manufacturing method comprises the following steps: sequentially depositing multiple layers of isolation materials on the front surface of the semiconductor substrate to form a stacked isolation layer; forming a polycrystalline silicon layer on the surface of the stacked isolation layer,and then photoetching and patterning to obtain a plurality of polycrystalline silicon thermocouples; depositing a silicon oxide film above the thermocouple, and photoetching and patterning to form anelectrode contact hole; depositing conductive metal in the electrode contact holes, patterning the conductive metal, then covering the metal with an infrared absorption layer, then patterning and etching the metal to the semiconductor substrate, and breaking through the front suspension bridge; forming a protective layer on the surface of the semiconductor substrate in the front surface direction,then depositing silicon oxide on the back surface of the semiconductor substrate to serve as a mask layer, and selectively etching the semiconductor substrate until the silicon oxide penetrates through the semiconductor substrate to form a back cavity; and removing the protective layer, and optionally obtaining the thermopile device with the suspension bridge structure through a subsequent process. The process is simple, and convenience is provided for manufacturing the thermopile with the suspension bridge structure.

Description

technical field [0001] The invention relates to the field of semiconductor production technology, in particular to a method for manufacturing a thermopile device with a suspension bridge structure. Background technique [0002] At present, infrared detectors are widely used in civilian and military fields, and thermopile infrared detectors are the earliest developed among many types of infrared detectors. Due to its advantages of being able to work at room temperature, wide response band, and low production cost, it develops extremely rapidly and is widely used. In the process preparation of thermopile infrared detectors, the compatibility of its manufacturing process with the integrated circuit process is the main way to form a large-scale detection array, improve the detection responsivity, and reduce the process manufacturing cost. [0003] In order to establish effective heat conduction between the hot junction area and the cold junction area, it is necessary to build a...

AI Technical Summary

Problems solved by technology

In terms of heat insulation effect of thermopile, suspension bridge has more advantages, because the membrane structure is surrounded by an atmosphere medium (such as air) with poor thermal conductivity, so the heat dissipation is small, the thermal resistance is high, and the heat insulation effect is good. At the same time, the absorbed heat can be effectively conducted along the direction of the thermocouple pair, so the thermoelectric conversion efficiency is better and the sensitivity is high; and for the closed film, after absorbing infrared radiation, the heat can propagate along the dielectric support film instead of Propagate along the thermocouple pair, so the heat dissipation is relatively large, the thermoelectric conversion efficiency is low, and the sensitivity is small

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