Pyroelectric infrared detector for planarization thermal isolation structure and method for making same

Abstract

The invention discloses a pyroelectric infrared detector provided with a planarized heat-insulated structure and a preparation method thereof. The pyroelectric infrared detector comprises a substrate and the heat-insulated structure, wherein the heat-insulated structure is as follows: a deep notch of a corresponding figure of a lower electrode of a detector is etched on the silicon or sapphire substrate; a porous silicon dioxide layer is deposited inside the deep notch; and silicon dioxide layers or silicon nitride layers are deposited on the porous silicon dioxide layer and the substrate. The detector is easy to be integrated with other devices by means of single scale intergration, is favorable for high-density integration of detector units, has simple manufacturing technique and low processing cost, simultaneously greatly reduces the vertical height difference of steps of a mesa device structure, is easy to interconnect metals, reduces the difficulty of the processing technique of devices and the surface leakage current of the devices, improves the performance and the finished product rate of the pyroelectric infrared detector, and obviously improves the reliability of the devices. The detector provided with the structure is suitable for infrared-ultraviolet dual-range single scale intergration and manufacture of the infrared detector and a CMOS ROIC one chip integrated focal plane device.

Description

technical field [0001] The invention belongs to the technical field of optical detectors, in particular to a pyroelectric infrared detector with a planar thermal insulation structure and a preparation method thereof. Background technique [0002] Pyroelectric infrared detectors are widely used in industry, environment, medical treatment, military, etc. It has become one of the hot spots in the field of infrared technology research. There are two key factors affecting the performance of pyroelectric infrared detectors: one is the performance of the ferroelectric thin film material, and the other is the structure of the detector unit; The thermal conductivity and the heat capacity of the device are improved, so the design of the thermal insulation structure of the detector unit is a key factor in the production of high-performance devices. The thermal insulation structures of pyroelectric infrared detectors that have been reported mainly have three forms: composite film mesa...

AI Technical Summary

Problems solved by technology

The first is the porous SiO2 / SiO2 composite membrane mesa structure, which is relatively simple, but the high steps affect passivation and metallization interconnection and other issues , which increases the difficulty of the process and the surface leakage current of the device, and it is not easy to monolithically integrate with other devices, and the process compatibility is poor; the air gap and micro-bridge structure, these two structures have good heat insulation effect, but the manufacturing process is complicated, which increases the cost , low yield

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