Author : Fei Huang (Researcher in electrical engineering)
Release : 2023
Genre :
Kind : eBook
Book Rating : /5 ( reviews)
Book Synopsis Zirconium-doped Hafnium Oxide Based Ferroelectric Materials for Memory Applications by : Fei Huang (Researcher in electrical engineering)
Download or read book Zirconium-doped Hafnium Oxide Based Ferroelectric Materials for Memory Applications written by Fei Huang (Researcher in electrical engineering). This book was released on 2023. Available in PDF, EPUB and Kindle. Book excerpt: As data processing and storage needs continue to grow at a rapid pace, the development of innovative memory technologies is crucial. The discovery of ferroelectricity in hafnia (HfO2)-based materials has garnered significant attention in both academia and industry, owing to their potential to revolutionize non-volatile memory (NVM) technology and enable novel computing architectures. HfO2-based ferroelectric materials offer advantages over conventional perovskite oxides, such as low-temperature synthesis and conformal growth in three-dimensional structures on silicon, making them compatible with complementary metal-oxide-semiconductor (CMOS) technology and ideal for device scaling. However, several challenges still exist for implementing ferroelectric HfO2 in commercial products, such as polarization variation during cycling (wake-up effect), high operation voltage, compatibility with back-end-of-line (BEOL) processing temperatures, and low memory density. In this dissertation, I tackled the challenges outlined above. I began by focusing on the Hf0.5Zr0.5O2 (HZO) material itself and addressing the wake-up effect through the introduction of an HfO2 buffer layer at the HZO/electrode interface. Subsequently, I developed a new measurement setup capable of directly measuring individual nm-sized devices, which enabled investigating the scaling effect in HZO-based ferroelectric capacitors. Through my research, I was able to demonstrate excellent ferroelectricity and reliability in ultra-thin HZO (4 nm) capacitors with molybdenum (Mo) electrodes. These capacitors exhibited low operation voltage, wake-up-free behavior, high endurance, and low RTA temperatures, making them highly desirable for practical applications. I also studied the size scaling effect down to 65 nm × 45 nm devices, where I observed ultra-high remanent polarization (2Pr) for the first time at this scale. In addition to exploring two-dimensional scaling to improve density, I also proposed a hybrid structure for 4 bits/cell storage, increasing the multi-bit capability in a single cell.
