Study of the Interfacial Properties of Heterostructures Based on Aluminum and Hydrogenated Diamond

Recently, scientific research has demonstrated that the use of hydrogenated diamond as a P-type material can be a relevant innovation for the production of new generation field-effect transistors (FET) [1-3]. To create FETs based on hydrogenated diamond, it is necessary to evaluate its behavior in contact with the materials that are used to form the NPN junction. In the case of the source and drain terminals of the FET, N-type metallic materials are generally used to form a Schottky barrier at the interface with the P-type material. Due to its ease of production and integration, one of the most used metals is o Aluminum [4]. Although there are already studies on the evaluation of the properties of composites based on pure diamond and aluminum [5], it is still not known whether (and how) the use of hydrogenated diamond would alter such properties, which is essential to determine the feasibility of use in FET construction. Through theoretical studies of Molecular Dynamics using reactive force fields, in this work we study how the degree of hydrogenation on the diamond surface affects the diamond/metal interface, especially when subject to temperature variations. Using degrees of hydrogenation on the diamond surface of 0%, 15%, 25%, 50%, 75% and 100%, we notice that at room temperature, 75% hydrogenation is already capable of preventing chemical interaction between the diamond and the aluminum. However, from 500K onwards, even with 75% hydrogenation of the surface, a small fraction of aluminum atoms begin to interact with the diamond. As electronic devices can be subject to high temperatures and to ensure that interfacial properties do not change during operation, our results suggest that a high degree of hydrogenation of the diamond surface (&gt;75%) is required to ensure that there is no chemical interaction. between the diamond.<br/><br/>[1] ZHOU, C. J.; et al., Appl. Phys. Lett. 2019, 114, 063501.<br/>[2] PHAM, T. T.; et al., Appl. Phys. Lett. 2017, 111, 173503.<br/>[3] KOIZUMI, S.; PERNOT, J.; UMEZAWA, H.; SUZUKI, M. Power Electronics Device Applications of Diamond Semiconductors, 1a ed., Woodhead Publishing, 2018.<br/>[4] DIMITRIJEV, S. Principles of Semiconductor Devices (The Oxford Series in Electrical and Computer Engineering), 2a ed., Oxford University Press, 2011.<br/>[5] ZHU, P.; et al., Compos. Part A Appl. 2022, 162, 107161.