Effect of Process Parameters on Co-Sputtered Al(1-x)ScxN Layer's Properties: Morphology, Crystal Structure, Strain, Band Gap, and Piezoelectricity

Nguyen Quoc, Khánh and Horváth, Zsolt Endre and Zolnai, Zsolt and Petrik, Péter and Pósa, László and Volk, János (2024) Effect of Process Parameters on Co-Sputtered Al(1-x)ScxN Layer's Properties: Morphology, Crystal Structure, Strain, Band Gap, and Piezoelectricity. MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING : FUNCTIONAL MATERIALS FOR (OPTO)ELECTRONICS, SENSORS, DETECTORS, AND GREEN ENERGY, 169. No.-107902. ISSN 1369-8001 (print); 1873-4081 (online)

Text 1-s2.0-S1369800123005954-main.pdf Restricted to Repository staff only Download (6MB) | Request a copy

Abstract

The effect of pulse direct current (DC) reactive ion co-sputtering parameters on the morphology, crystal structure, residual stress, band gap, and piezoelectric properties of the Al(1-x)ScxN thin film deposited in large target-to-substrate distance (TSD) system has been studied using Scanning Probe Microscopy, X ray Diffractometry, Spectroscopic Ellipsometry, and profilometer, among others. The process pressure was revealed to be the key factor which essentially determines the quality of the film for such system. As low as 0.2 Pa working pressure is needed to achieve smooth nitride layer with good piezoelectric properties. High N2/(Ar + N2) gas ratio also was shown to result in better film properties. Residual stress in nitride film, and thereby the optical band gap can be tuned by variation of process pressure, gas ratio, and Sc fraction in the studied x range (0–0.5). The Al(1-x)ScxN film deposited at low pressure, medium N2 gas ratio with x ∼ 0.41 shows high piezoelectric coefficient, relatively low residual stress, and smooth surface. Top electrode has been applied to eliminate the interfering effect of the restraining force induced by the unexcited matrix materials around tip/sample contact for Piezoresponse Force Microscopic (PFM) measurement of piezoelectric constant of thin nitride film. We have shown by comparing the corrected d33corr data determined with PFM to those obtained from direct piezoelectric method that PFM using proper measurement conditions and correction can be applied as a quantitative method for study of piezoelectric properties of thin film.

Actions (login required)

Edit Item