Piezoelectric properties of polycrystalline AlN thin films for MEMS application

Abstract The piezoelectric coefficient d 33eff of aluminium nitride thin films was measured using both, the piezoresponse force microscopy and an interferometric technique. Wurtzite AlN thin films were prepared on Si (1 1 1) substrates by reactive dc-sputtering and by metal organic chemical vapor deposition (MOCVD). Direct measurements of the inverse piezoelectric effect in the picometer range showed that the acceptable tolerance in the crystal orientation is much larger for MEMS applications than expected previously. The value of the effective piezoelectric coefficient d 33 for the prepared AlN thin films remained as high as 5.1 pm/V even for lower degrees of texture.

[1]  O. Ambacher,et al.  Piezoresponse force microscopy for polarity imaging of GaN , 2002 .

[2]  Oliver Ambacher,et al.  Growth and applications of Group III-nitrides , 1998 .

[3]  J. Bläsing,et al.  Optical and structural properties of highly c-axis oriented aluminum nitride prepared by sputter-deposition in pure nitrogen , 2000 .

[4]  F. Bernardini,et al.  First-principles calculation of the piezoelectric tensor d⇊ of III–V nitrides , 2002 .

[5]  S. Muensit,et al.  Extensional piezoelectric coefficients of gallium nitride and aluminum nitride , 1999 .

[6]  R. Reif,et al.  Measurements of the bulk, C-axis electromechanical coupling constant as a function of AlN film quality , 2000, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[7]  A. Kingon,et al.  Measurement of the effective piezoelectric constant of nitride thin films and heterostructures using scanning force microscopy , 2001 .

[8]  Toshio Kamiya,et al.  Calculation of Crystal Structures, Dielectric Constants and Piezoelectric Properties of Wurtzite-Type Crystals Using Ab-Initio Periodic Hartree-Fock Method , 1996 .

[9]  Xiao-Hong Xu,et al.  Morphological properties of AlN piezoelectric thin films deposited by DC reactive magnetron sputtering , 2001 .

[10]  M. A. Respaldiza,et al.  Influence of oxygen and argon on the crystal quality and piezoelectric response of AlN sputtered thin films , 2004 .

[11]  Judith A. Ruffner,et al.  Effect of substrate composition on the piezoelectric response of reactively sputtered AlN thin films , 1999 .

[12]  V. Kmetik,et al.  Measurement of piezoelectric constants using an optical heterodyne interferometer , 1992 .

[13]  J. Gardner,et al.  Microsensors, MEMS, and Smart Devices , 2001 .

[14]  P. Muralt,et al.  Thickness dependence of the properties of highly c-axis textured AlN thin films , 2004 .

[15]  Alan Francis Wright,et al.  Elastic properties of zinc-blende and wurtzite AlN, GaN, and InN , 1997 .

[16]  O. Ambacher,et al.  The role of Si as surfactant and donor in molecular-beam epitaxy of AlN , 2005 .