| Summary: | 碩士 === 國立清華大學 === 電子工程研究所 === 87 === It is a tendency using the mature CMOS technology to fabricate cheaper but higherperformance image sensors to take
place CCDs in imaging applications. There are severalkinds of CMOS image sensor, such as photo-gate type, photo-diode
type, etc. In this paper, we will focus on these two types of imager to measure their dark current, saturation level,sensitivity
and other characteristics by designing a variety of active pixeltest-keys. Therefore, we can analyze their
formingmechanisms, and then improve theimaging qualities by changing the process parameters of these devices, unlike
others'methods : bettering the imaging qualities through external image processing. We will design and develop other new
image sensor structures toimprove the characteristics without changing standard CMOS technology or with least changes.
Besides, we will set up a measurement system to facilitate our research. Andwe will go toward one-million-pixel CMOS
image sensor in the near future.
CMOS image sensor has some advantages: low cost, low power consumption and high integrate. We must understand
effects upon the sensing quality detail to improve CMOS imager. In this paper, we design different structures of photodiode
in CMOS imager base on the 0.6mm CMOS technologic of TSMC. We find N+-P photodiode has good characteristic in
dark current and dynamic range measurement; the structure of N-Well has good characteristic in sensitivity and sensing
speed measurement. On the other hand, we design a new "Wafer Level" measurement system.
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