由哺乳類動物視網膜生物模型所設計之金氧半仿視網膜晶片

Abstract

於本論文中，我們提出一個依據由哺乳類動物視網膜建立之生物模型所設計的仿視網膜矽晶片；文中亦詳論其特性與工作原理。一原本應用於細胞非線性網路機器(CNN-UM)的生物模型為此仿視網膜晶片的基礎架構；晶片之功能為模仿哺乳類動物視網膜內的光受器(photoreceptor)及水平細胞(horizontal cell)。 此晶片包含一個大小為32x32，可實現光受器及水平細胞功能的影像感測陣列；陣列中包含了許多完全相同的基本單元。每個基本單元中又包含四個主要部份：光輸入元件、光受器一、光受器二與水平細胞元件。晶片中還包括了輸出、輸入接墊(I/O pads)的靜電防護與位址解碼(Address decoder)及訊號讀出等電路。 藉由一維陣列的電路模擬(HSPICE)結果，我們驗證此晶片在空間域及時域的特性；而實際的二維感測陣列則利用0.35微米金氧半矽製程製造，用來測試實際的晶片反應。最後，我們比較原本生物模型的結果與電路模擬及實際電路量測的結果之異同以檢驗此晶片的正確性與待改進之處。

In this thesis, a retinal chip based on the biological model derived from the mammalian retina is proposed. The CMOS compatible retinal chip is designed based on the biological retinal model originally established for the implementation on CNN Universal Machine (CNN-UM) to mimic the functions of the photoreceptors and the horizontal cell and other cells in mammalian retina. The retinal chip contains a focal plane sensory array of 32x32 similar basic cells that perform the functions of photoreceptor and the horizontal cell. Each basic cell contains four main parts: photo-input, PH1, PH2, and the horizontal. ESD protection circuit for I/O pads, address decoder and other readout circuits are also included in this chip. Spatial and temporal characteristics of a one-dimensional array are verified via HSPICE simulations, while a two-dimensional array of 32x32 cells is fabricated to investigate the space-time pattern that this chip appears with subjected to a certain stimulus. The retinal chip is fabricated in 0.35µm double-poly triple-metal CMOS process. The results of HSPICE simulation and chip measurement are compared with that of the original biological model to examine the consistency and the difference for further improvements.