Large Area Electronics, Applications and Requirements

Abstract

Large area, matrix addressed, pixel arrays are used for active matrix liquid crystal displays (AMLCD) and more recently are being introduced for medical X-ray imaging devices. These arrays and their applications for computer displays and medical imaging are summarized. The arrays are steadily increasing in size, with the largest being >40 cm on a side, and have as many as 5 to 10 million pixels. The need for accurate control of gray scale information in both LCDs and image sensors is a further challenge to the array design and fabrication technology. The performance of the arrays depends on the properties of the thin film transistors (TFT) and sensors in the pixels. The paper outlines the requirements demanded by the different applications, it terms of size, pixel count, addressing speed, and noise etc. These requirements influence the choice of the device materials and design, with particular emphasis on TFT properties such as mobility, leakage current and parasitic capacitance, and influence the choice of laser re-crystallized silicon or amorphous silicon devices. The integration of drive, readout and control electronics on the array substrate is a further opportunity for high performance laser recrystallized TFTs.