應用於下視網膜植入具太陽能電池及分區供電之65奈米互補式金氧半64像素雙向刺激晶片設計

Abstract

本篇論文提出及分析應用於下視網膜互補式金氧半太陽能電池刺激晶片移植系統，晶片架構基於分區供電方式改良輸出刺激電流之效率。在雙井式互補式金氧半製程中利用P型基底浮接感光之N+/P-well 接面光二極體以及在P型井中之N型通道金氧半電晶體並以深層N型井(DNW)加以隔絕避免光電流漏電。實驗之晶片包含三個利用四區和八區分區供電之8x8的光二極體陣列以及控制訊號產生電路。而這些晶片分別採用台積電0.18um以及65nm互補式金氧半標準製程工藝。最終的晶片尺寸為2.8mm x 2.8mm，在80mW/cm2之訊號光以及40mW/cm2 之紅外線背景光照射下量測到八區控制訊號頻率為189赫茲；時脈頻率為1500赫茲，輸出的雙向刺激電流有9.9uA。此量測結果驗證了晶片可以正常操作。除此之外，體外與體內的動物實驗也成功地被實驗

In this thesis, a solar-cell powered CMOS current stimulation chip and an implant system for subretinal prostheses are proposed and analyzed. The chip structure is based on the proposed Divisional Power Supply Scheme (DPSS) to improve the efficiency of output stimulation current. N+/P-well photodiode structure with floating P-substrate and NMOSET in P-well with floating deep n-well (DNW) are adopted to prevent photocurrent leakage and enable CMOS devices integration in twin-well CMOS technology with DNW structure. The experimental chips consists of three 8×8 photodiode array with 4 and 8 divisions and control signal generator circuits. The experimental chips has been designed and fabricated in TSMC 0.18um and 65nm CMOS standard process technology respectively. The final chip size is 2.8 mm×2.8 mm. The measured frequency of four eight phase control signals is 189 Hz with the clock frequency of 1.5 kHz under 80mW/cm2 of signal light intensity and 40mW/cm2 of background IR. The measured output biphasic stimulation current is 9.9