Study of aluminum nitride films deposited on silicon for fabrication of MEMs devices

Péricles Lopes Santana,Aledir Silveira Pereira ,Argemiro Soares Da Silva Sobrinho ,Julio Cezar Faria ,Douglas Marcel Gonçalves Leite ,Newton Adriano Santos Gomes

doi:10.17563/rbav.v40.1198

Abstract

In this work, aluminum nitride (AlN) thin films deposited on the silicon (100) by RF magnetron-sputtering were analyzed. Nitrogen and argon plasmas were used in a vacuum system technique, being possible to obtain films oriented to the (oo2) crystallographic direction analyzed by X-ray diffraction (XRD) technique. Scanning electronic microscopy (SEM) was used to obtain the chemical composition (% at.) of AlN thin films. SEM analyses were accomplished to verify the images of the AlN films. Raman spectroscopy was used to obtain the Raman displacement as a function of the light intensity of the beam incident on the AlN films. Therefore, it was possible to reach the peaks of laser radiation absorption (λ = 514 nm) during Raman scattering. Ellipsometry was required to obtain: the roughness (Rz), optical gap (E04), and films thickness. Optical properties of the films depend on the temperature during the deposition. COMSOL software was required to simulate the performance of MEMS device, operating in the match circuit on a few ten of MHz resonance frequency.

Highlights

The III-V nitrides are potential candidates for optoelectronic applications owing to their direct and broadband gaps
For these and other reasons, aluminum nitride (AlN) is a potential candidate for use in the manufacture of microelectromechanical systems (MEMs), including those ones using surface acoustic waves (SAWs)[3]
The structural characterization of the thin films was performed by means of X-ray diffraction (XRD) measurements, as shown in the diffractogram of Figs. 1 and 2, provided by the software of equipment, the Panalytical X’Pert[3] Powder, using the powder method

Summary

Introduction

The III-V nitrides are potential candidates for optoelectronic applications owing to their direct and broadband gaps. Study of aluminum nitride films deposited on silicon for fabrication of MEMs devices surface acoustic speed, thermal conductivity, dielectric constant, and stability and hardness at high temperatures[2] For these and other reasons, AlN is a potential candidate for use in the manufacture of microelectromechanical systems (MEMs), including those ones using surface acoustic waves (SAWs)[3]. AlN has become very popular in resonator application owing to its high electrical resistivity, homogeneous grain nucleation along the c axis and constant piezoelectric performance throughout the operating frequency[2] In the latter field the ability to deposit high-quality films on silicon substrates by spraying at low temperature[3] allowed the manufacture of chip integrated signal filters for telecommunication devices in the ultra-high frequency (UHF) regime, based on MEMs devices[4]. High-quality epitaxial AlN films on suitable substrates are essential for this application

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Conclusion