AVS 57th International Symposium & Exhibition
    MEMS and NEMS Thursday Sessions
       Session MN-ThP

Paper MN-ThP10
Improvement of Optical Properties in 3D CMOS Image Sensor (CIS) by Using Insertion Structure of Metal Slot

Thursday, October 21, 2010, 6:00 pm, Room Southwest Exhibit Hall

Session: MEMS and NEMS Poster Session
Presenter: G.-M. Han, Chonnam National University, Republic of Korea
Authors: S.-Y. Kim, Korea Polytechnic College IV, Republic of Korea
G.-M. Han, Chonnam National University, Republic of Korea
N.-H. Kim, Chonnam National University, Republic of Korea
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High integrated CMOS image sensor (CIS) has contimuously decreased the area of photodiode in CIS structure. This is the origitnated reason to decline the optical characteristics of CIS including optical generation collection efficiency (CE), and crosstalk. Although the conventional structure used the PD structure with shallow trench isolation (STI) for pixel-to-pixel isolation, this structure brought out the high leakage characteristics. To improve this leakage problem, the conventional process employed the counter-doping method of impurities; however, this method could not solve the crosstalk problem by the obliquely incoming light. In this study, both the counter-doping of impurities and insertion of metal slot into the center of counter-doping were proposed to form the pixel-to-pixel isolation. This structure carried out the role of wave-guide with the excellent light reflection characteristics of metal as well as the conventional ground of contact. The crosstalk issue was successfully improved with the enhancement of the optical generation characteristics of 3D CIS by using this novel structure instead of the conventional STI pixel-to-pixel isolation method.