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Characterization of Hydrogenated Boron Carbide and Boron Carbon Nitride Thin Films and Applications

MetadataDetails
Publication Date2021-01-01
JournalSTARS (University of Central Florida)
AuthorsShraddha Dhanraj Nehate

Dimension scaling has been the driving force for improved performance of semiconductor integrated circuits (ICs) for the past few decades. While the semiconductor industry continues to achieve returns on Moore’s law, the resistance-capacitance (RC) delay remains a critical bottleneck towards further performance improvement. To support advanced computing performance, the development and integration of new low dielectric (low-k) materials to reduce the capacitance of interconnects are crucial. Apart from the low dielectric constant value, one of the other vital parameters to replace the current dielectric material is mechanical stability. Materials in the boron, carbon, and nitrogen ternary triangle have emerged promising low dielectric materials. The combination of boron, carbon, and nitrogen leads to unique materials exhibiting distinct properties from graphite to boron carbide (B4C), boron nitride (BN), boron carbon nitride (BCN) compounds going from metallic to semiconducting to insulating. BCN compounds combine properties of diamond to display excellent mechanical properties and reproduce BN semiconducting properties with adjustable bandgaps. The dielectric constant (k) value of B4C and BCN is between 4-6. This dissertation attempted to reduce the k value of B4C and BCN by introducing non-polar bonds in the materials through hydrogenation using the RF magnetron sputtering technique. Thin films were deposited by single or dual-target sputtering from B4C and BN targets by varying hydrogen to nitrogen reactive gas and substrate temperature. All the films demonstrated distinct composition at different growth parameters and displayed evidence of tunable properties with film composition. It was shown that tuning film composition achieves low-k values while ensuring no deterioration in the mechanical properties of thin films. Moreover, the influence of hydrogenation and variation in substrate temperature was investigated on B4C and BCN properties for applications in electrical, mechanical, and optical devices. Additionally, graphene analogous BCN nanocoating synthesized in this study exhibited outstanding inhibition against bacterial growth and biofilm formation, making them promising for biomedical devices.