Design Impact on Charge Transfer Inefficiency of Surface CCD on CMOS Devices: TCAD and Characterization Study

This paper presents a study of design optimization of charge-coupled device on CMOS devices, in order to minimize the charge transfer inefficiency (CTI). To achieve this goal, 3-D Technology Computer Aided Design (TCAD) simulations with a trap model at silicon-oxide interface were conducted, and measurements on two test chips manufactured on two different foundries were performed. TCAD simulations predict trends in agreement with measurements, but trap models at silicon trench isolation (STI) and gate oxides should be adapted accordingly to the technology used. Some design variations show results depending on the technology chosen, and the best CTI reduction is obtained with an increase of p-well inclusion over STI edges.

[1]  A. El Gamal,et al.  A 0.5 μm pixel frame-transfer CCD image sensor in 110 nm CMOS , 2007, 2007 IEEE International Electron Devices Meeting.

[2]  Edward S. Cheng,et al.  A comparison of charge transfer efficiency measurement techniques on proton damaged n-channel CCDs for the Hubble Space Telescope Wide-Field Camera 3 , 2001 .

[3]  M. J. Deen,et al.  Charge transfer efficiency in proton damaged CCD's , 1998 .

[4]  T. Lee,et al.  An Active Pixel Sensor Fabricated Using CMOS / CCD Process Technology , 1995 .

[5]  Olivier Marcelot,et al.  Study of CCD Transport on CMOS Imaging Technology: Comparison Between SCCD and BCCD, and Ramp Effect on the CTI , 2014, IEEE Transactions on Electron Devices.

[6]  R. L. Nielsen,et al.  A 360 000-pixel charge-coupled color-image sensor for imaging photographic negative , 1985, IEEE Transactions on Electron Devices.

[7]  Albert J. P. Theuwissen,et al.  CMOS image sensors: State-of-the-art , 2008 .

[8]  A. Tasch,et al.  Experimental characterization of transfer Efficiency in charge-coupled devices , 1975, IEEE Transactions on Electron Devices.

[9]  J. Johansson,et al.  Evaluation of a Surface-Channel CCD Manufactured in a Pinned Active-Pixel-Sensor CMOS Process , 2011, IEEE Transactions on Electron Devices.

[10]  G. Meynants,et al.  Time-Delay-Integration Architectures in CMOS Image Sensors , 2009, IEEE Transactions on Electron Devices.

[11]  James R. Janesick,et al.  Effects of proton damage on charge-coupled devices , 1991, Medical Imaging.

[12]  J. P. Krusius,et al.  Characteristics of submicrometer gaps in buried-channel CCD structures , 1991 .

[13]  B. De Monte,et al.  First measurements of true charge transfer TDI (Time Delay Integration) using a standard CMOS technology , 2017, International Conference on Space Optics.

[14]  M. Tompsett.  Surface potential equilibration method of setting charge in charge-coupled devices , 1975, IEEE Transactions on Electron Devices.

[15]  B. LaMarr,et al.  CCD Charge Injection Structure at Very Small Signal Levels , 2008, IEEE Transactions on Electron Devices.

[16]  P. Paillet,et al.  Analysis of Total Dose-Induced Dark Current in CMOS Image Sensors From Interface State and Trapped Charge Density Measurements , 2010, IEEE Transactions on Nuclear Science.