Research Projects

Research Rationale: Ferroelectric materials like Hafnium Zirconium Oxide (HZO) and Aluminium Scandium Nitride (AlScN) have exhibited significant potential for non-volatile memory (NVM) applications due to their ability to sustain polarization states without bias voltage and CMOS compatibility. However, performance uniformity, low data retention, and endurance present ample challenges upon scaling which are targeted in the proposed research work for next-generation ferroelectric NVM. Scientific Objectives: 1. To fabricate nanoelectronics standard sub-10 nm ultrathin films of HZO and AlScN. 2. To investigate the ferroelectric characteristics of HZO and AlScN thin films. 3. To refine the scalable deposition method/process, ensure the integration feasibility with standard CMOS technology, and achieve consistent ferroelectric performance. 4. Fabrication of prototype NVM devices such as Metal/HZO/Metal, Metal/AlScN/Metal, Metal/HZO/high-k/Si, Metal/AlScN/high-k/Si and effect of scaling to critical dimensions. 5. Performance and Reliability assessment of NVM devices. Hypothesis/Model: The central hypothesis posits that HZO and AlScN ferroelectric materials can provide superior ferroelectric properties (higher coercive field and remnant polarization) and maintain compatibility with CMOS processes. The integration with an optimum high-k buffer layer can lead to the development of advanced NVM devices with enhanced performance, scalability, and reliability. Key Experiments: 1. Thin Film Formation: Utilize techniques such as sputtering and atomic layer deposition to deposit HZO and AlScN ultrathin films at optimum process conditions. 2. Thin film characterization: Employ methods like piezoresponse force microscopy and X-ray diffraction to measure ferroelectric properties & phase formation. 3. Investigation of metal-ferroelectric-metal (MFM) structures: To examine P-E hysteresis loops, coercive field, and remnant polarization with variation in material, physical, and process parameters. 4. Fabrication of Prototype NVM Devices: Metal-ferroelectric-insulator-semiconductor (MFIS) structures with high performance and reliability. 5. Performance and Reliability Evaluation: Testing the prototype devices for performance (memory window, leakage) and reliability (endurance, data retention) under various environmental conditions. Significance of Research: The outlined objectives will enhance the understanding of HZO and AlScN ferroelectric material systems and their application in NVM devices. The proposed HZO based NVM is expected to be suitable for low-power applications. While AlScN NVM can be helpful for defence and space applications. The successful development of high-performance, reliable, and scalable NVM devices using these materials is expected to address existing limitations, open new avenues for advancements in data storage technologies and revolutionize fields such as artificial intelligence, big data, and Internet of Things.