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Title: AlN texturing and piezoelectricity on flexible substrates for sensor applications

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.
Authors:
; ;  [1] ; ; ;  [2] ; ;  [3] ;  [4] ;  [5]
  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)
Publication Date:
OSTI Identifier:
22415112
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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