• Kaplan-Ashiri, Ifat
• Cohen, Asaf
• Ehre, David
• Kossoy, Anna
• Khodorov, Sergey
• Cohen, Hagai
• Cohen, Sidney R.
• Frenkel, Anatoly
• Wachtel, Ellen
• Lubomirsky, Igor
• Feldman, Yishay

Abstract

<jats:p>A protocol for successfully depositing [001] textured, 2–3 µm thick films of Al0.75Sc0.25N, is proposed. The procedure relies on the fact that sputtered Ti is [001]-textured α-phase (hcp). Diffusion of nitrogen ions into the α-Ti film during reactive sputtering of Al0.75,Sc0.25N likely forms a [111]-oriented TiN intermediate layer. The lattice mismatch of this very thin film with Al0.75Sc0.25N is ~3.7%, providing excellent conditions for epitaxial growth. In contrast to earlier reports, the Al0.75Sc0.25N films prepared in the current study are Al-terminated. Low growth stress (&lt;100 MPa) allows films up to 3 µm thick to be deposited without loss of orientation or decrease in piezoelectric coefficient. An advantage of the proposed technique is that it is compatible with a variety of substrates commonly used for actuators or MEMS, as demonstrated here for both Si wafers and D263 borosilicate glass. Additionally, thicker films can potentially lead to increased piezoelectric stress/strain by supporting application of higher voltage, but without increase in the magnitude of the electric field.</jats:p>

Topics

• impedance spectroscopy
• phase
• thin film
• glass
• reactive
• glass
• Nitrogen
• tin