Vertical-cavity　surface-emitting　lasers(VCSELs)　are　widely　used　in　short-reached　optical　interconnects　and　data　communication　links　because　of　their　low　energy　consumption　and　high　modulation　speed.　Capacitance,　as　the　parasitic　parameters,　affects　the　modulation　bandwidth.　In　this　paper,　parasitic　capacitance　of　VCSELs　is　reduced　by　using　a　low-k　benzocyclobutene(BCB)　planarization　technique.　The　detail　BCB　planarization　technique　has　been　discussed　with　optimal　process　parameters,　which　is　useful　for　high-speed　VCSEL　fabrication.　The　small　signal　modulation　bandwidth　of　the　low-k　BCB　planarization　VCSEL　with　7　μm　oxide　aperture　has　been　achieved　to　15.2　GHz.　©　2018,　China　Science　Publishing　&　Media　LTD.　All　right　reserved.