CMOS Image Sensor Hot Pixels Study
|Keywords||CMOS image sensor CIS Process technology Hot pixels|
CMOS image sensor has advantages of high integration, low power consumption, low cost etc. It has been widely used in many fields such as the cell phones, digital cameras, PC cameras, surveillance systems, toys, automotive electronics and medical equipment and other areas, which make it become a hot research increasingly .The hot pixel is a key factor that restricts the quality of the image. This paper focuses on the way to control the hot pixel during the manufacturing of the CMOS image sensor.Base on the CMOS image sensor Final Test result for the much more hot pixels, this paper covers its manufacturing process, related technical features, the testing and the evaluate method. After using experimental batch method that is widely used in semiconductor manufacturing foundries to analyze this question, it is found that the root reason is the "PIN IMP" process issue. After comparing and analyzing the equipments and manufacturing process of the "PIN IMP", it is proposed that modify-ing "PIN IMP" process order may get improvement. And then its feasibility and reliability are verified. In the result, the number of hot pixels in the CMOS image sensor reduce from 500～600 to 120 or less. This paper has positive significance and great value to the microelectronics manufacturing technology.