用于微机电系统的物理气相沉积AlScN薄膜中平面外弯曲应力梯度的补偿，低平面外弯曲。

Compensation of the Stress Gradient in Physical Vapor Deposited AlScN Films for Microelectromechanical Systems with Low Out-of-Plane Bending.

作者信息

Beaucejour Rossiny, D'Agati Michael, Kalyan Kritank, Olsson Roy H

机构信息

Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 220 S. 33rd St., Philadelphia, PA 19104, USA.

Department of Electrical and Systems Engineering, University of Pennsylvania, 3205 Walnut St., Philadelphia, PA 19104, USA.

出版信息

Micromachines (Basel). 2022 Jul 24;13(8):1169. doi: 10.3390/mi13081169.

DOI:10.3390/mi13081169

PMID:35893167

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9394260/

Abstract

Thin film through-thickness stress gradients produce out-of-plane bending in released microelectromechanical systems (MEMS) structures. We study the stress and stress gradient of AlScN thin films deposited directly on Si. We show that AlScN cantilever structures realized in films with low average film stress have significant out-of-plane bending when the AlScN material is deposited under constant sputtering conditions. We demonstrate a method where the total process gas flow is varied during the deposition to compensate for the native through-thickness stress gradient in sputtered AlScN thin films. This method is utilized to reduce the out-of-plane bending of 200 µm long, 500 nm thick AlScN MEMS cantilevers from greater than 128 µm to less than 3 µm.

摘要

薄膜的贯穿厚度应力梯度会在释放的微机电系统（MEMS）结构中产生面外弯曲。我们研究了直接沉积在硅上的AlScN薄膜的应力和应力梯度。我们表明，当在恒定溅射条件下沉积AlScN材料时，在平均薄膜应力较低的薄膜中实现的AlScN悬臂结构会有显著的面外弯曲。我们展示了一种方法，即在沉积过程中改变总工艺气体流量，以补偿溅射AlScN薄膜中固有的贯穿厚度应力梯度。该方法用于将200 µm长、500 nm厚的AlScN MEMS悬臂的面外弯曲从大于128 µm减小到小于3 µm。