Fabrication of Aluminum Oxide Thin-Film Devices Based on Atomic Layer Deposition and Pulsed Discrete Feed Method

Shih-Chin Lin; Ching-Chiun Wang; Chuen-Lin Tien; Fu-Ching Tung; Hsuan-Fu Wang; Shih-Hsiang Lai

doi:10.3390/mi14020279

Fabrication of Aluminum Oxide Thin-Film Devices Based on Atomic Layer Deposition and Pulsed Discrete Feed Method

Micromachines (Basel). 2023 Jan 21;14(2):279. doi: 10.3390/mi14020279.

Authors

Shih-Chin Lin¹, Ching-Chiun Wang¹, Chuen-Lin Tien², Fu-Ching Tung¹, Hsuan-Fu Wang¹, Shih-Hsiang Lai¹

Affiliations

¹ Mechanical and Systems Research Lab, Industrial Technology Research Institute, Hsinchu 310401, Taiwan.
² Department of Electrical Engineering, Feng Chia University, Taichung 40724, Taiwan.

Abstract

This study demonstrates the low-temperature (<100 °C) process for growing a thin silica buffer layer and aluminum oxide by atomic layer deposition (ALD) in the same reaction chamber. Heterogeneous multilayer thin films are prepared by a dual-mode equipment based on atomic layer deposition and plasma-enhanced chemical vapor deposition (PECVD) techniques. The pulse discrete feeding method (DFM) was used to divide the precursor purging steps into smaller intervals and generate discrete feeds, which improved the saturated distribution of gas precursors, film density and deposition selectivity. The experimental results show that the process method produces a uniform microstructure and that the best film uniformity is ±2.3% and growth rate is 0.69 Å/cycle. The thickness of aluminum oxide film has a linear relationship with the cyclic growth number from 360 to 1800 cycles. Meanwhile, the structural and mechanical stress properties of aluminum oxide thin films were also verified to meet the requirements of advanced thin-film devices.

Keywords: aluminum oxide; atomic layer deposition; buffer layer; mechanical stress; plasma-enhanced chemical vapor deposition; pulsed discrete feed method; thin film.

Grants and funding

This research was supported in part by the National Science and Technology of Council, under project number 111-2622-E-035-003. This study was also supported by Feng Chia University (Contract No. 21H00723).