Kim, Yoonjin Kwon, Heungdong Han, Hyun Soo Kim, Hyo Jin K. Kim, Brian S. Y. Lee, Byung Chul Lee, Joohyun Asheghi, Mehdi Prinz, Fritz B. Goodson, Kenneth E. Lim, Jongwoo Sim, Uk Park, Woosung 2024-01-19T16:32:35Z 2024-01-19T16:32:35Z 2021-09-02 2020-10 1944-8244 https://pubs.kist.re.kr/handle/201004/118070 The ability to control the properties of dielectric thin films on demand is of fundamental interest in nanoscale devices. Here, we modulate plasma characteristics at the surface of a substrate to tune both dielectric constant and thermal conductivity of amorphous thin films grown using plasma enhanced atomic layer deposition. Specifically, we apply a substrate bias ranging from 0 to similar to 117 V and demonstrate the systematic tunability of various material parameters of Al2O3. As a function of the substrate bias, we find a nonmonotonical evolution of intrinsic properties, including density, dielectric constant, and thermal conductivity. A key observation is that the maximum values in dielectric constant and effective thermal conductivity emerge at different substrate biases. The impact of density on both thermal conductivity and dielectric constant is further examined using a differential effective medium theory and the Clausius-Mossotti model, respectively. We find that the peak value in the dielectric constant deviates from the Clausius-Mossotti model, indicating the change of oxygen fraction in our thin films as a function of substrate bias. This finding suggests that the increased local strength of plasma sheath not only enhances material density but also controls the dynamics of microstructural defect formation beyond what is possible with conventional approaches. Based on our experimental observations and modeling, we further build a phenomenological relation between dielectric constant and thermal conductivity. Our results pave invaluable avenues for optimizing dielectric thin films at the atomic scale for a wide range of applications in nanoelectronics and energy devices. English American Chemical Society Tunable Dielectric and Thermal Properties of Oxide Dielectrics via Substrate Biasing in Plasma-Enhanced Atomic Layer Deposition Article 10.1021/acsami.0c11086 1 ACS Applied Materials & Interfaces, v.12, no.40, pp.44912 - 44918 ACS Applied Materials & Interfaces 12 40 44912 44918 scie scopus 000579956100051 2-s2.0-85092749560 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article ALUMINUM-OXIDE AL2O3 TEMPERATURE FILMS CONDUCTIVITY ALD SILICON GROWTH atomic layer deposition dielectric constant thermal conductivity mass density plasma