차세대 DRAM 전극을 위한 원자층 증착법 기반 SnO2 박막의 연구

초록

Tin dioxide (SnO₂) is a transparent conductive oxide material that is currently being investigated for potential application in DRAM electrodes, driven by the increasing demand for semiconductor scaling. The practical limitations of increasing capacitance by continuously reducing the thickness of the dielectric film have led to a growing need for new dielectric materials. Among these materials, rutile-TiO₂ (k>100) is particularly noteworthy. However, synthesizing a high-k rutile phase requires high-temperature processes exceeding 700 °C, which are incompatible with the CMOS process. To overcome this challenge, the rutile structure of SnO₂ can be employed as a seed layer, enabling the low-temperature synthesis of rutile TiO₂ via local epitaxy. In this study, we developed a method for synthesizing low-resistivity rutile SnO₂ by atomic layer deposition (ALD) without the use of ozone, which has the inherent potential to oxidize the DRAM bottom electrodes. We believe that the SnO₂ seeds layer can be utilized to fabricate of the next generation of dielectric films, rutile TiO₂, regardless of bottom electrode type.