Recent Progress on Metal Oxide Semiconductor Thin Film Transistor Application via Atomic Layer Deposition Method

Abstract

On these days, display industries have rapidly adopted high-performance oxide semiconductors (OS, such as amorphous InGaZnO semiconductor) as an active layer in active matrix organic light-emitting diodes (OLEDs), liquid crystal display (LCD), and flexible active matrix device applications. In this talk, I will present the recent progress of OS materials and the associated device application. Unlike commercial sputtering method, atomic layer deposition (ALD) can make an opportunity to enhance not only device performances but also flexible properties. First, I will show various oxide semiconductors deposited by ALD and compare with their semiconductor properties and device performances. Also, multicomponent oxide semiconductors (such as ZnSnO, InZnO, InGaO, InZnSnO, InGanZnO, etc.), deposited by super cycle ALD methods, will be discussed regarding process issues vs. material properties. Then, I will show the effect of various ALD-based gate insulators on oxide semiconductor thin film transistors (TFTs). The ALD-based gate insulators will be important roles to consider panel and circuit designs. The mobility and stability of the devices will be discussed in terms of gate insulators. The flexible oxide semiconductor thin film transistors will be presented via ALD methods, and the device may be evaluated by mechanical stresses such as bending radius and mechanical fatigue. This work will be an important suggestion for ALD-based device applications.