Enhanced sensitivity achievement using advanced device simulation of multifinger photo gate active pixel sensors

Phanindra V. R. H. Kalyanam; Glenn H. Chapman; Ash M. Parameswaran

doi:10.1117/12.839157

25 January 2010 Enhanced sensitivity achievement using advanced device simulation of multifinger photo gate active pixel sensors

Phanindra V. R. H. Kalyanam, Glenn H. Chapman, Ash M. Parameswaran

Author Affiliations +

Proceedings Volume 7536, Sensors, Cameras, and Systems for Industrial/Scientific Applications XI; 75360G (2010) https://doi.org/10.1117/12.839157
Event: IS&T/SPIE Electronic Imaging, 2010, San Jose, California, United States

Abstract

A 2-dimensional device simulation of Multi finger active pixel sensors is investigated for obtaining enhanced pixel sensitivity. Photo gate APS use a MOS capacitor that can capture incident illumination with a potential well created under the photo gate. The major drawback of such a technology is the absorption of shorter wavelength by the polysilicon gate resulting in a higher sensitivity in the red visible spectrum than in the blue range. In our previous work we implemented 0.18μm CMOS standard and multi fingered photo gate design where the enclosed detection area is divided by 3, 5 and 7 fingers. The experimental results showed that fringing field created potential wells for the 3 and 5 finger photo gate designs have 1.7 times higher collection of photo carriers over the standard photo gate. The device simulation showed that fringing fields from the edges of the poly gates created potential wells that fully covered the open silicon areas allowing light conversion without the optical absorption in the poly silicon gates. Extending simulations to 0.5 μm, 0.25 μm and 0.18 μm multifinger poly gates showed that the fringing fields stayed the same width as the gates shrunk, so that as the number of fingers increased the potential well in the open areas became more uniform. The device sensitivity based on the potential well locations, and previous experimental results, suggested peak efficiencies for the 0.5 μm design as 7 fingers, 0.25 μm at 9 fingers and 0.18 μm at 11 fingers. Peak efficiency was projected to be 2.2 times that of a standard photogate.

Citation Download Citation

Phanindra V. R. H. Kalyanam, Glenn H. Chapman, and Ash M. Parameswaran "Enhanced sensitivity achievement using advanced device simulation of multifinger photo gate active pixel sensors", Proc. SPIE 7536, Sensors, Cameras, and Systems for Industrial/Scientific Applications XI, 75360G (25 January 2010); https://doi.org/10.1117/12.839157

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available