Room Temperature Growth and Investiagtion of Electrical Properties of Amorphous Boron Nitride

C.L. Arnold, M. Dockins, C. Muratore, N.R. Glavin, N.D. Shepherd, A.A. Voevodin
University of North Texas,
United States

Keywords: amorphous BN, 2D materials, electrical properties

Summary:

Traditional material and processing techniques for nanoelectronics are approaching a ceiling, requiring a paradigm shift. 2D materials have emerged as leading candidates for next-generation nanoelectronics. Research and development have created numerous conducting and semiconducting 2D materials for futuristic transistors, capacitors, batteries, and memory devices; however, 2D dielectric materials have not received the same attention. Advancement in nanoelectronics based on 2D materials will only occur when matching reliable, high dielectric strength, transparent, and chemically inert 2D dielectric materials are established. Several insulating materials (such as BN, HfO, Al2O3, etc) are believed to be suitable candidates for transistor gate dielectrics, an environmental passivation layer, and other device elements. However, the obstacle of obtaining required insulating properties at low temperatures constrains the progress of integrating these materials with nanodevices, particularly those on soft or flexible substrates. In this study, we demonstrate the use of pulsed magnetron RF sputtering to grow amorphous boron nitride (a-BN) at room temperature as a possible solution. Film thickness in the range of 10 – 20 nm was determined using a Veeco Dektak 150 stylus profilometer and atomic force microscopy (AFM), and their chemical composition determined using X-ray photoelectron spectroscopy (XPS). Electrical properties such as dielectric constant, leakage current, and breakdown strength were determined using M-I-M structures consisting of W/a-BN/Ti. Exploration of oxide charges at the a-BN interface was achieved using M-I-S structures and frequency-dependent capacitance-voltage (C-V) and conductance-voltage (G-V) measurements to evaluate the potential of a-BN. An understanding of the defect chemistry and their influence on the properties of a-BN is discussed.