Rochester Institute of Technology RIT Scholar Works Theses 2005 Operating, testing and evaluating hybridized silicon P-I-N arrays Andrew C. Moore Follow this and additional works at: https://scholarworks.rit.edu/theses Recommended Citation Moore, Andrew C., "Operating, testing and evaluating hybridized silicon P-I-N arrays" (2005). Thesis. Rochester Institute of Technology. Accessed from This Dissertation is brought to you for free and open access by RIT Scholar Works. It has been accepted for inclusion in Theses by an authorized administrator of RIT Scholar Works. For more information, please contact [email protected]. Operating, Testing and Evaluating Hybridized Silicon P-I-N Arrays by Andrew C. Moore B.S.E.E. State University of New York at Buffalo 1986 M.S.E.E. Rochester Institute of Technology 1991 A Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Chester F. Carlson Center for Imaging Science Rochester Institute of Technology 2005 SIgnature. of the Author ____________________Andrew C. Moore _ Accepted by __N_a_m_e_I_II_e-=-9_ i b_l_e __---=c?L=----~_ . -=-.,f,f--' _~~- Coordinator, Ph.D. Degree Program Date CHESTER F. CARLSON CENTER FOR IMAGING SCIENCE ROCHESTER INSTITUTE OF TECHNOLOGY ROCHESTER, NEW YORK CERTIFICATE OF APPROVAL Ph.D. DEGREE DISSERTATION The Ph.D. Degree Dissertation of Andrew C. Moore has been examined and approved by the dissertation committee as satisfactory for the dissertation required for the Ph.D. degree in Imaging Science Zoran Ninkov Dr. Zoran Ninkov, Ph.D. Advisor Ian Gatley Dr. Ian Gatley William J. Forrest Dr. William J. Forrest P. R. Mukund Dr. P. R. Mukund to (t,iJo \ Date iii DISSERTATION RELEASE PERMISSION ROCHESTER INSTITUTE OF TECHNOLOGY COLLEGE OF SCIENCE CHESTER F. CARLSON CENTER FOR IMAGING SCIENCE Title of Dissertation: Operating, Testing and Evaluating Hybridized Silicon P-I-N Arrays I, Andrew C. Moore, hereby grant permission to Wallace Memorial Library of R.I.T. to reproduce my thesis in whoIe' or in part. Any reproduction will not be for commercial use or profit. Signature Andrew C. Moore v Operating, Testing and Evaluating Hybridized Silicon P-I-N Arrays by Andrew C. Moore Submitted to the Chester F. Carlson Center for Imaging Science in partial fulfillment of the requirements for the Doctor of Philosophy Degree at the Rochester Institute of Technology Abstract Use of CCD detector arrays as visible imagers in space telescopes has been problematic. Charge-coupled devices rapidly deteriorate due to damage from the high radiation environ ment of space. CMOS-based imagers, which do not transfer charge, offer an alternative technology that is more tolerant of a high-radiation environment. "pathfinder" This dissertation evaluates the performance of four IK by IK hybridized silicon P-I-N detector arrays made by Raytheon under subcontract to RIT as candidates for use in a space telescope application. Silicon P-I-N arrays have photon capture properties similar to back-thinned CCD's and should be far more robust than CCD's in the high- radiation environment of space. The first two devices, 1 80 [im thick prototypes, demon strate crisp imaging with lateral diffusion of 5 microns at 35 Kelvin. The nodal capacitance is estimated to be 41 fF and the quantum efficiency is remarkably good (typically > 0.75) over a spectral range from 410 to 940 nm. A second pair of devices, fabricated with de tectors thinned to 40 ixm, exhibits similar performance but with blue-enhanced spectral response from an improved anti-reflective coating. Operating, testing, and evaluating imaging devices similar to the ones tested here is also problematic. Precise, low-noise, flexible control systems are required to operate the devices, and interpretation of the data is not always straightforward. In the process of eval- vn uating these pathfinder devices, this dissertation surveys and advances systems engineering and analysis (i.e. the application of linear and stochastic system theory) generally useful for "staring" arrays. Most operating and evaluating similar hybridized focal plane significantly, a previously unaccounted for effect causing significant errors in the measurement of quan tum efficiency inter-pixel capacitive coupling is discovered, described, measured, and compensated for in the P-I-N devices. This coupling is also shown to be measurably present in hybridized indium antimonide arrays. Simulations of interpixel coupling are also performed and predict the coupling actually observed in the P-I-N devices. Additional analysis tools for characterizing these devices are developed. An optimal es timator of signal on a multiply-sampled integrating detector in the presence of both photon and read noise is derived, modeling a pixel as a simple linear system, and is shown to agree with known limiting cases. Theories of charge diffusion in detectors are surveyed and a system model based on the steady state diffusion equation, infinite lifetime, and contiguous pixels is derived and compared to other models. Simulations validate this theory and show the effect of finite mean free path, finite lifetime, and non-contiguous pixels upon it. A simple method for modeling and evaluating MTF from edge spread is developed and used. A model that separately measures system and device noise in multichannel systems is de veloped, and shown to agree with measurements taken with the same device in both a quiet and a somewhat noisy system. Hardware and software systems that operate these devices 'agile' are also surveyed, and technologies and development methodologies apprate for de tector research are employed to build a simple and flexible array control system, primarily from open-source components. The system is used to collect much of the experimental data. vm IX Acknowledgements in" Thanks first go to Zoran Ninkov for "taking me when I was looking for a dissertation topic that could utilize my skills and interests in electronics and system design. He was imaginative enough to envision a research possibil ity along those lines. His upbeat and easy-going attitude has made the expe rience enjoyable as well as educational. The expert guidance of University of Rochester Near Infrared Astronomy Lab professors Bill Forrest and Judith Pipher contributed much to my experience, and their support, encouragement, and patience has been overwhelming. I spent many hours in their lab, learning not only about devices and device testing, but also about people and team work. NIR Lab engineer Craig McMurtry always provided information and guidance. Rich Sarkis aided with all things computer. Candice Bacon's usage of the system and subsequent enhancement requests greatly improved its us ability. Working with Zoran and the NIR Lab connected me intimately with a large astronomical community. Greg Burley and Carnegie Observatories were the originators of the open-source electronics that was built upon here. Greg, a remarkably sharp electronics systems engineer, always had answers for my questions. The Raytheon team was a pleasure to work with. Ken Ando, Alan Hoffman, Peter Love, Jerry Cripe, Joe Rossbeck, Nancy Lum and others from the Raytheon team were very supportive. The Space Telescope Science In stitute, in particular Bernie Rauscher, Ernie Morse and Louis Bergeron of the Independent Detector Testing Lab were a constant wealth of information and insight. STScI's Paul Barrett was very helpful in many Python related issues. Association with Don Figer, Steve Beckwith, and others in the STScI fam ily helped to connect this research to a bigger perspective. The scientists at NASA Goddard and NASA Ames were always supportive, helpful, and infor "McSquad" mative. The at NASA Ames (Craig McCreight, Bob McMurray, Mark McKelvey) were happy to take time to listen to my ideas and relate their neighborhood." experiences to me one day when I was "in the Association with NASA Goddard Space Flight Center connected me with Bob Martineau and a group of other engineers and scientists. Along the way, I also met, exchanged email with, or teleconferenced with Al Fowler, James Garnett, Paul Hickson, Marcia Rieke, Gert Finger, James Beletic, Roger Smith, Bob Leach, and many others. It has truly been an honor to be a part of this community. The Cen ter for Imaging Science has been quite supportive as well. Previously directed by Ian Gatley and currently directed by Stefi Baum, it is well-connected with the issues of astronomical imaging. Robert Kremens helped with electronics ideas. Bob Slawson was quick to provide application insights. Sue Chan and Cindy Schultz tried to keep my ducks in something resembling a row. Dani Guzman, an RIT Imaging Science student at CalTech has shown great interest in the controllers. I hope his collaboration in this project grows and continues. Special thanks to Rich Hailstone and Judy Pipher for the suggestions and cor- xi rections they provided for this dissertation. In addition, recognition must be given to Tarry Polidor of Optical Gaging Products and Quality Vision Interna tional. His patience and support throughout this research have been more than I could have ever hoped for. Thanks especially to my wife Judy for her patience and support. This has been a long endeavor, for my family especially. My 10 year old son Joey (a newborn when I was just starting) chose stars and planets for his bedroom wallpaper after learning that I was working on electronics and software to help make better cameras for telescopes. Joey and my two other sons, Robert ("Chance") and