Discipline: Nanoscience or Materials Science
Subcategory: Materials Science
Kelsea Yarbrough - Norfolk State University
Co-Author(s): Makhes Behera, Norfolk State University, Norfolk, VirginiaSangram Pradhan, Norfolk State University, Norfolk, VirginiaMessaoud Bahoura,Norfolk State University, Norfolk, Virginia
Over the past decades, silicon dioxide (SiO2) is the most used dielectric for electronics devices including metal oxide semiconductor capacitors (MOSCAP), metal oxide semiconductor field effect transistors (MOSFET), thin film transistors (TFT), and very large-scale integration technology (VLSI). SiO2 is used extensively because it is cheap and easy to grow. However, SiO2 is facing difficulties in terms of scaling down the device size because it shows higher leakage current during device operations. Researchers have been actively searching for alternative materials for the replacement of the longstanding traditional SiO2. Scaling down electronics is the most popular and somewhat easier approach from the performance point of view, where SiO2 will not be able to withstand these adjustments. One tactic to scaling down electronics, while supporting satisfactory dielectric properties is the incorporation of high k dielectrics. Noteworthy high k dielectrics that are of our current research interest include hafnium oxide (HfO2), zirconium oxide (ZrO2), and aluminum oxide (Al2O3). We used atomic layer deposition (ALD) to grow these large area and conformal high k dielectrics thin films with fixed thickness on a p-type silicon substrate at different growth temperatures. MOSCAP’s were fabricated to observe the dielectric integrity of the device. The MOSCAP devices were post-annealed at 800⁰C in an oxygen ambient environment for 1 hour. Fabricated MOSCAP devices displayed a low current density of 10 -8 A/cm2, a surface roughness of 0.197 nm and a high capacitance of 698 pF. The effect of growth and post-annealing on the structure and surface morphology, crystallinity, capacitance, and dielectric properties was systematically analyzed through several measurement techniques such as X-ray diffraction, atomic force microscopy, raman spectroscopy, and ultraviolet visible spectroscopy.
Funder Acknowledgement(s): This work is supported by the NSF-CREST Grant number HRD 1547771 and NSF-CREST Grant number HRD 1036494.
Faculty Advisor: Messaoud Bahoura, firstname.lastname@example.org
Role: My contribution to this research project included device fabrication, device analysis, theoretical development, and material selection and characterization.