The Latest Plasma-Enhanced Chemical-Vapor Deposition Technology for Large-Size Processing

The thin-film transistor liquid crystal display (TFT-LCD) industry has in recent years demanded ever-larger- area substrate processing capability to keep up with consumer market demands for larger and larger displays. This paper discusses the latest plasma-enhanced chemical-vapor deposition (PECVD) system, the AKT 50 K PECVD, which handles up to 2160 x 2460 mm² substrates. As substrate size increases, lowering the processing temperature is getting even more important to improve production reliability and cost performance. The most commonly used process temperature for the so-called active layers of amorphous silicon (a-Si) TFTs is approximately 350 degC. In this paper, a newly developed single-chamber low-temperature PECVD active-layers process is discussed. In particular, our low-temperature process maintains film performance at the same level as high-temperature active layers while also maintaining system productivity and throughput.