互補式金氧半導體影像感測器技術（一）

Abstract

近來，互補式金氧半導體影像感測器已經受到廣泛的注意，顧客對於微型化、低功率、低成本的需求成為受到持續關注的主要原因。互補式金氧半導體影像感測器提供了整合超大型積體電路中各個系統在同一個晶片上的機會，並且減少了電路版上分離電路元件的數量，降低包裝成本。一個包含時序控制器，感測器陣列，訊號處理器，類比到數位轉換器，數位介面的單晶片照相機是可預期的。在標準邏輯電路電壓提供下，此單晶片照相機的功率消耗僅有數十毫瓦。 互補式金氧半導體影像感測器包含了三個重要部分：第一個是像素陣列，第二個是晶片內部的訊號處理，而第三個是可變增益放大器。互補式金氧半導體影像感測器運用在高解析度方面，將會面臨像素尺寸過大的問題，因此一個像素中只含三個電晶體的架構被採用來克服此困難。晶片內部的訊號處理可以使用來加強互補式金氧半導體影像感測器的效能與功能。一般的方法是使用關連雙倍取樣(CDS)的方法來減少像素重置時的kTC雜訊，像素內源極追隨放大器的1/f雜訊，以及不同像素中源極追隨放大器不同的臨界電壓所造成的固定式樣雜訊。可變增益放大器用來產生彩色濾波器式樣。 互補式金氧半導體影像感測器之設計使用台積電之標準邏輯製程(0.35um)，工作電壓3.3伏特，操作在25百萬赫茲，像素陣列是640乘以480。

Recently, there has been a growing interest in CMOS image sensors. The major reason for this interest is the customer demand for miniaturized, low-power, and low-coast digital cameras. CMOS image sensors offer a great potential to integrate a significant amount of VLSI electronics on a single chip and reduce discrete components and packaging costs. It is now straightforward to envision a single-chip camera that has integrated timing and control electronics, sensor array, signal processing electronics, analog-to-digital converter (ADC) and full digital interface. Such a camera-on-a-chip will operate with standard logic supply voltages and consume power measured in the tens of milli-watts. The CMOS image sensor under studies includes three important parts: the first is pixel array, the second is on-chip signal processing and the third is programmable-gain amplifier. The pixel size is the key point for CMOS image sensors in high-resolution applications. In this thesis, the structure of three transistors is proposed. On-chip analog signal processing can be used to improve the performance and functionality of a CMOS image sensor. The general method is to use correlated-double-sampling (CDS) to suppress kTC noise from pixel reset, 1/f noise from the in-pixel source follower amplifier, and fixed-pattern-noise (FPN) originating from pixel-to-pixel variation in source-follower threshold voltage. The programmable gain settings are used to create color-filter-patterns. The CMOS image sensor uses the standard logic process offered by TSMC (0.35um) with applied voltage of 3.3v and operates at 25MHz, and the pixel array is 640*480.