Monoclinic　β　phase　Ga2O3　has　been　considered　as　a　promising　candidate　for　next　generation　radio　frequency　and　high-power　devices　because　of　its　ultrawide　bandgap　and　high　breakdown　field.　The　development　of　epitaxial　growth　techniques　and　the　synthesis　of　high　quality　β-Ga2O3　thin　films　are　crucial　for　the　device　applications.　In　this　work,　the　heteroepitaxial　β-Ga2O3　thin　films　were　grown　on　sapphire　(0001)　substrates　by　low　pressure　chemical　vapor　deposition.　The　influence　of　growth　parameters　such　as　the　source/substrate　temperatures,　the　oxygen/Ar　gas　flow　rates,　and　the　surface　morphology　of　substrate　on　the　resultant　crystallinity　and　surface　roughness　of　the　β-Ga2O3　films　were　investigated.　The　β-Ga2O3　heteroepitaxial　layer　on　sapphire　exhibits　an　RMS　roughness　of　1.82　nm,　an　XRD　rocking　curve　of　1.18°,　and　a　growth　rate　of　0.72　μm/h.　The　β-Ga2O3　film　grown　on　the　buffer　layer　exhibit　a　smoother　surface,　whereas　the　chemical　etching　and　annealing　lead　to　an　improved　crystallinity　and　a　rough　surface.　However,　there　is　a　trade-off　between　the　crystallization　and　the　surface　roughness.　©　2021　Elsevier　Ltd