Deposition of ultrathin AlN films for high frequency electroacoustic devices

Abstract

Articles you may be interested inSynthesis and characterization of 10nm thick piezoelectric AlN films with high c-axis orientation for miniaturized nanoelectromechanical devices Appl. Phys. Lett.

Piezoelectric aluminum nitride thin films for microelectromechanical systems

“…High resolution TEM analyses have shown that these ultrathin fi lms have a fi ne columnar texture and a continuous lattice microstructure within a single grain from the interface with the Mo layer through to the AlN surface, thus confi rming the presence of a strong orientation even in the 25-nm-thick fi lm. 65 Preliminary characterizations of these ultrathin AlN fi lms performed in collaboration with Polytechnic University of Madrid (solidly mounted BAW resonators), 62 University of California-Berkeley (Lamb wave resonators), 68 and University of Pennsylvania piezoelectric nanoelectromechanical actuators) 10 , 69 validate the study's potential as a technological base by which to further increase operation frequency and overall performance of different types of electroacoustic devices.…”

“…65 Note that a smooth and well-textured bottom electrode is imperative for growth of highly c -axis oriented AlN fi lms. As a polar material with the wurtzite structure, an AlN fi lm with the c -axis perpendicular to the substrate can have two physical orientations of the columnar grains with the fi lm surface terminating in either the aluminum or nitrogen basal plane.…”

“…65 For the deposition of highly textured AlN fi lms with thicknesses below 200 nm, a dualtarget S-gun magnetron was employed. 66 In the S-gun for reactive sputtering, an alternating current (40 kHz) power applied between two concentrically nested ring-shaped targets creates a plasma discharge at the conical face of each target.…”

Aluminum nitride as nonlinear optical material for on-chip frequency comb generation and frequency conversion

“…1(a) shows the essential fabrication process steps. In this device, the 650-nm thick AlN is deposited on 2-µm thick thermally grown SiO 2 on Si substrate using an S-gun magnetron sputtering system [45]. The deposited film has around ±75 MPa stress and high c-axis orientation.…”

Low-thickness high-quality aluminum nitride films for super high frequency solidly mounted resonators

“…SHF applications require a remarkable reduction of the thickness of the AIN films to values for which their crystal quality and piezoelectric activity drop significantly [9], owing to the poor crystal quality of the material in the initial stages of growth. BAW resonators based on ultra thin AIN films (from 150 nm to 300 nm) are being developed in some research institutions and companies [1][2][3][10][11][12][13][14]. However, the crystal quality of such films is still far from that of thicker films.…”