Approaches for 3D Integration Using Plasma-Enhanced Atomic-Layer-Deposited Atomically-Ordered InGaZnO Transistors with Ultra-High Mobility

Abstract

As the scale-down and power-saving of silicon-based channel materials approach the limit, oxide semiconductors are being actively researched for applications in 3D back-end-of-line integration. For these applications, it is necessary to develop stable oxide semiconductors with electrical properties similar to those of Si. Herein, a single-crystal-like indium–gallium–zinc–oxide (IGZO) layer (referred to as a pseudo-single-crystal) is synthesized using plasma-enhanced atomic layer deposition and fabricated stable IGZO transistors with an ultra-high mobility of over 100 cm2 Vs−1. To acquire high-quality atomic layer deposition-processed IGZO layers, the plasma power of the reactant is controlled as an effective processing parameter by evaluating and understanding the effect of the chemical reaction of the precursors on the behavior of the residual hydrogen, carbon, and oxygen in the as-deposited films. Based on these insights, this study found that there is a critical relationship between the optimal plasma reaction energy, superior electrical performance, and device stability.