An　ultraviolet　(UV)　laser　lift-off　(LLO)　technique　was　presented　to　form　a　roughened　surface　morphology　on　GaN　membrane　grown　by　metalorganic　chemical　vapor　deposition　(MOCVD).　The　etched　surface　showed　cone-like　structures　on　a　free-standing　GaN　membrane.　Based　on　the　scanning　electron　microscopy　(SEM)　and　atom　force　microscopy　(AFM)　measurements,　the　etching　mechanism　was　proposed,　which　was　related　to　the　different　decomposition　depth　caused　by　the　dislocations　in　the　GaN　membrane.　The　etching　efficiency　and　morphology　of　GaN　by　the　LLO　technique　and　the　photoelectrochemical　(PEC)　wet　etching　technique　was　compared　and　analyzed.　This　roughed　cone-like　surface　morphology　by　LLO　can　enhance　the　external　efficiency　of　vertical　structure　n-side-up　GaN-based　light-emitting　diodes　(LEDs)　simultaneously　while　being　released　of　the　performance　constrains　impeded　by　sapphire.