• Shifat, Zadid
• Stricklin, Isaac
• Siddiqui, Aleem
• Busani, Tito
• Chityala, Ravi Kiran

Abstract

<jats:p>A wide bandgap, an enhanced piezoelectric coefficient, and low dielectric permittivity are some of the outstanding properties that have made ScxAl1−xN a promising material in numerous MEMS and optoelectronics applications. One of the substantial challenges of fabricating ScxAl1−xN devices is its difficulty in etching, specifically with higher scandium concentration. In this work, we have developed an experimental approach with high temperature annealing followed by a wet etching process using tetramethyl ammonium hydroxide (TMAH), which maintains etching uniformity across various Sc compositions. The experimental results of etching approximately 730 nm of ScxAl1−xN (x = 0.125, 0.20, 0.40) thin films show that the etch rate decreases with increasing scandium content. Nevertheless, sidewall verticality of 85°~90° (±0.2°) was maintained for all Sc compositions. Based on these experimental outcomes, it is anticipated that this etching procedure will be advantageous in the fabrication of acoustic, photonic, and piezoelectric devices.</jats:p>

Topics

• impedance spectroscopy
• thin film
• aluminium
• nitride
• annealing
• Scandium
• wet etching