Waqas Bashir | EPFL Graph Search

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Effect of AlN seed layer on crystallographic characterization of piezoelectric AlN

Paul Muralt, Luis Guillermo Villanueva Torrijo, Annalisa De Pastina, Ramin Matloub Aghdam, Kaitlin Marie Howell, Waqas Bashir

Ultrathin aluminum nitride (AlN) films are of great interest for integration into nanoelectromechanical systems for actuation and sensing. Given the direct relationship between crystallographic texture and piezoelectric (PZE) response, x-ray diffraction has become an important metrology step. However, signals from layers deposited below the PZE AlN thin film may skew the crystallographic analysis and give misleading results. In this work, the authors compare the use of a Ti or AlN seed layer on the crystallographic quality of PZE AlN. The authors also analyze the influence of several AlN seed layer thicknesses on the rocking curve FWHM of PZE AlN and demonstrate a larger effect of the AlN seed layer on the theta-2 theta AlN crystallographic peak for increasing AlN seed layer thickness. Published by the AVS.

2019

50 nm thick AlN Films for Actuation and Detection of Nanoscale Resonators

Paul Muralt, Luis Guillermo Villanueva Torrijo, Annalisa De Pastina, Ramin Matloub Aghdam, Kaitlin Marie Howell, Waqas Bashir

We report on the optimization of a multilayer platinum/aluminum nitride (AlN) stack with an AlN active layer thickness of 50 nm for piezoelectric actuation in nanoelectromechanical systems (NEMS). Experiments in reactive sputtering of AlN were used to find optimal parameters for good crystallinity and low residual stress of a four layer film stack, shown in Figure 1. A direct relationship was measured between the AlN seed layer thickness and the x-ray diffraction (XRD) rocking curve’s full width at half maximum (FWHM) of the AlN active layer. However, no influence of seed layer thickness was found in double beam laser interferometric measurements of the clamped longitudinal piezoelectric coefficient d33,f, relating thickness strain from an applied electric field, of the XRD measured four layer film stacks.

2016