Impact of Zr Content in Atomic Layer Deposited Hf1−Zr O2 Thin Films

Abstract Atomic layer deposition (ALD) is the most preferred film growth process of the ferroelectric Hf 1 −  x Zr x O 2 thin films ( x  ~ 0.5) due to its characteristic self-limiting growth behavior. Mass-production of high- k HfO 2 and ZrO 2 films in logic transistors and dynamic random access memory capacitors, respectively, has clearly manifested their advantage in the fabrication process. However, the investigation of Hf 0.5 Zr 0.5 O 2 thin films deposited by the ALD method has been hampered because the involvement of ferroelectric properties should be suppressed. In this chapter, research on the atomic layer deposited Hf 1 −  x Zr x O 2 thin films is reviewed. The effects of various factors, such as film thickness, Zr/(Hf + Zr) ratio, deposition temperature, annealing atmosphere, and annealing temperature on the chemical, physical, and resulting electrical properties are systematically examined based on the previous studies. This chapter will summarize the experimental and theoretical results from various research groups from the authors’ best knowledge and will suggest the direction of future research in this field.