AlN texturing and piezoelectricity on flexible substrates for sensor applications

Journal Article · Mon Jun 08 04:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4922229· OSTI ID:22415112

Smecca, Emanuele; Pellegrino, Giovanna; Alberti, Alessandra ^[1]; Maita, Francesco; Maiolo, Luca; Fortunato, Guglielmo ^[2]; Vinciguerra, Vincenzo; La Magna, Luigi ^[3]; Mirabella, Salvo ^[4]; Condorelli, Guglielmo G. ^[5]

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1. CNR-IMM, Zona Industriale Strada VIII, n°5, 95121 Catania (Italy)
2. CNR-IMM, Via del Fosso del Cavaliere 100, 00133 Roma (Italy)
3. STMicroelectronics, Stradale Primosole 50, 95121 Catania (Italy)
4. CNR-IMM, Matis Via Santa Sofia n°64, 95123 Catania (Italy)
5. Dipartimento di Scienze Chimiche, Università degli Studi di Catania, V.le A.Doria 6, 95125 Catania (Italy)

We show that AlN-based piezocapacitors with relatively high piezoelectric coefficient (d{sub 33}) values (3–4 pC/N) can be fabricated on polyimide (PI) substrates at 160 °C or even at room temperature by sputtering processes. With respect to PI, a reduction of the piezoelectric performances was observed on polyethylene naphthalate (PEN). With the same approach, a d{sub 33} value as high as 8 pC/N was achieved on rigid substrates (SiO{sub 2}/Si). In all cases, a thin Al buffer layer was deposited, immediately before AlN, without breaking the vacuum in the deposition chamber, in order to preserve the interface from contaminations that would obstruct the optimal atomic stratification with the desired [0001] growth axis. The piezoelectric behavior was thus correlated to the degree of texturing of the AlN layer through the evaluation of the XRD texturing coefficients and to the morphology by means of AFM analyses. We show that a high level of roughness introduced by the PEN substrate, coupled with the effect of the substrate flexibility on the piezoelectric coefficient, reduces the impact of the AlN texturing on the d{sub 33} values.

• OSTI ID: 22415112
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 23 Vol. 106; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM NITRIDES
ATOMIC FORCE MICROSCOPY
LAYERS
PIEZOELECTRICITY
POLYETHYLENES
SILICON OXIDES
SPUTTERING
SUBSTRATES
TEMPERATURE RANGE 0273-0400 K
TEXTURE
X-RAY DIFFRACTION