CMOS Image Sensors Sensitivity Improvement Via Process Optimization

With the development of manufacturing technology of Integrated Circuit and the improvement of IC design along with its advantages, CMOS Image Sensor using CMOS techniques have been widely used in many areas. Examples include digital electronic products, video electronic mail, medical equipment, security monitor systems, video communication, retina identification, industrial video monitors, video toys…etc. The market is wide open, especially in the area of digital products, therefore it is very useful and valuable to research and develop the CMOS Image Sensors.First, an overview on the research background, development history and the trend of technology are given. Then comparisons are done on advantages and disadvantages of CIS and CCD. Then the paper introduces the system structure and role of CIS, the components and function of CIS chip, and working flow of CMOS image sensors adopting 4T technology.Finally, in this thesis, the emphasis is to research the photoelectric effect and analysis factor that impact the light sensitivity of CIS, such as Quantum Efficiency and Optical Efficiency. One photon simulation tool is introduced and used to simulate the transmittance of dielectrics with different thickness. Based on this, we review the CIS chip structure and initiate one method from the manufacture process to improve the light sensitivity of CIS, and emphasize on the process development and experiment result.