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By far one of the most common questions that we receive from various users is how to thermally evaporate Aluminum. Aluminum is very commonly evaporated for various applications and can be somewhat problematic. Through some internal experience and through with working with various customers, we recommend two ways to approach thermal evaporation of aluminum.

Dr. Kai Ni from the research group of Professor Suman Datta, Stinson Professor of Nanotechnology at the University of Notre Dame, in collaboration with Purdue University and Kurt J. Lesker Company recently developed conformal atomic layer deposition (ALD) based hafnium zirconium oxide thin film processes displaying excellent electrical properties for potential gate oxide complement or replacement in scaled logic and memory technology nodes. The findings were recently published and showcased in the IEEE International Electron Devices Meeting (IEDM) 2019 in San Francisco, CA [ref. 1]. In particular, hafnium zirconium oxide (Hf_xZr_1-xO₂, or HZO) has emerged as a ferroelectric (large charge density per unit area) material system that also displays a tunable permittivity or dielectric constant (charge response) depending on the concentration of Zr added to the base HfO2 oxide. The reported films indicate that by sweeping the concentration of Zr in HfO₂ during the ALD growth, a substantial boost in the dielectric constant can be observed around 70% Zr concentration due to the presence of a crystallographic phase transition of the underlying HZO material structure, which results in enhanced electrical performance even in ultrathin films 25Å thick [ref. 2]. These findings elucidate the necessity and importance of extremely stringent deposition process control along with corresponding electrical and structural characterization for the understanding of new materials systems for their further implementation in commercial applications such as high-performance digital and analog CMOS technology at advanced nodes.