59.2: Development of Ni Sputtering System for Mass Production of Large AMOLED TV Based on SGS Technology

Abstract

Abstract‘Super Grain Silicon’ (SGS) technology, a non‐laser crystallization method, to fabricate LTPS TFT backplane for large AMOLED TV is known to require an extremely small amounts of Ni (1012∼14 atoms/cm2) deposited onto a‐Si thin film. We developed the world's first, prototype generation 6 (Gen 6, 1,500 × 1,850 mm) Ni sputtering system for SGS method. For such sputtering system to be employed for mass production, we should confirm the main performances of the system such as the uniformity of Ni distribution, the controllability, and reproducibility of Ni deposition. In this work, we revealed that the grain size of SGS poly‐Si ranged from about 10 μm to about 130 μm by controlling some of main factors such as the substrate moving speed and the electrical power density of Ni target. The sputtering system also showed an excellent reproducibility of average value of 30 μm with a variation of ±5 μm for 43 substrates. At this time, the crystallization of SGS poly‐Si was over 88%, and the grain size uniformity was less than 10% within Gen 6 substrate area. In addition to the performance of the system, we will discuss its basic concepts and potentials to be used as a system for mass production of AMOLED TV on large substrates such as Gen 8 (2,200 × 2500 mm) to Gen 11 (3,000 × 3,200 mm).