Image sensor and manufacturing method thereof

Abstract

The invention belongs to the technical field of semiconductor integrated circuit manufacturing technology, and discloses an image sensor and a manufacturing method thereof. The image sensor comprises a semiconductor substrate, an interlayer dielectric layer, contact electrodes, a perovskite photoelectric film, a passivation layer and a three-primary-color filtering film. A photoelectric conversion unit is enabled to be separated from other functional units through introduction of the perovskite photoelectric film, and the two-dimensional planer structure of a conventional CMOS image sensor is optimized into a three-dimensional laminated structure. The image sensor based on the perovskite photoelectric film can have 100% of filling coefficient, and the chip size is greatly reduced. Besides, the technological requirement for extremely low noise of a silicon photodiode does not need to be considered in the manufacturing process of the chip so that the technological requirement can be reduced and cost can be substantially reduced.

Description

technical field [0001] The invention belongs to the technical field of semiconductor integrated circuit manufacturing technology, and relates to a pattern sensor and a manufacturing method thereof. Background technique [0002] Image sensors are an important part of digital cameras. According to different components, it can be divided into two categories: CCD (ChargeCoupledDevice, charge-coupled device) and CMOS (ComplementaryMetal-OxideSemiconductor, metal-oxide-semiconductor element). [0003] Pixel sensitivity, one of the important performance indicators of CMOS image sensors, is mainly determined by the product of the fill factor (the ratio of the photosensitive area to the entire pixel area) and the quantum efficiency (the number of electrons generated by photons bombarding the screen). In CMOS image sensors, active pixels are used in CMOS image sensors in order to achieve a noise index and sensitivity levels comparable to those of CCD converters. At the same time, th...

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Problems solved by technology

[0004] However, in recent years, as the pixel size of solid-state image sensors has become smaller and smaller, its light absorption area has also decreased. Due to the existence of active readout circuits, the fill factor of silicon photodiodes has continued to decrease, and the signal-to-noise ratio of the device has deteriorated.

In addition, due to the influence of the metal interconnection, only part of the incident light can enter the photodiode area, further degrading the performance of the image sensor

[0005] At the same time, the CMOS image sensor is an analog-digital mixed SoC chip. Because different functional units in the chip have different technical requirements, such as photodiodes require extremely low noise, readout of analog circuits requires a large scanning voltage, while digital circuits It requires a very fast computing speed, and it is difficult to meet all the requirements of different functional units on the same technology platform.

We can only make some trade-offs in the performance of different unit circuits, which reduces the performance of the device and increases the cost of the chip

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