Bi1.5Zn1.0Nb1.5O7　(BZN)　thin　films　were　prepared　on　Pt/TiO2/SiO2/Si(100)　substrates　at　650　degrees　C　under　an　oxygen　pressure　of　10　Pa　by　using　pulsed　laser　deposition　process.　The　crystallinity,　microstructure　and　electrical　properties　of　BZN　thin　films　were　investigated　to　verify　the　influences　of　post-annealing　thermal　process　on　them.　The　X-ray　diffractometer　(XRD)　results　indicate　that　all　Bi1.5Zn1.0Nb1.5O7　thin　films　without　post-annealing　process　or　with　post-annealing　in　situ　vacuum　chamber　and　in　oxygen　ambient　exhibit　a　cubic　pyrochlore　structure.　The　improved　crystallinity　of　BZN　thin　films　through　post-annealing　was　confirmed　by　XRD　and　scanning　electron　microscope　(SEM)　analysis.　Dielectric　constant　and　loss　tangent　of　the　as-deposited　BZN　thin　films　are　160　and　0.002　at　10　kHz,　respectively.　After　annealing,　dielectric　properties　of　thin　films　are　significantly　improved.　Dielectric　constant　and　loss　tangent　of　the　in　situ　annealed　films　are　181　and　0.0005　at　10　kHz,　respectively.　But　the　films　post-annealed　in　O-2　oven　show　the　largest　dielectric　constant　of　202　and　the　lowest　loss　tangent　of　0.0002,　which　may　attribute　to　the　increase　in　grain　size　and　the　elimination　of　oxygen　vacancies.　Compared　with　the　as-deposited　BZN　thin　films,　the　post-annealed　films　also　show　the　larger　dielectric　tunability　and　the　lower　leakage　current　density.　(c)　2012　Elsevier　B.V.　All　rights　reserved.