By　using　the　wafer　bonding　technique　and　wet　etching　process,　a　wafer　bonded　thin　film　AlGaInP　LED　with　wet　etched　n-AlGaInP　surfaces　was　fabricated.　The　morphology　of　the　etched　surface　exhibits　a　pyramid-like　feature.　The　wafer　was　cut　into　270　×　270　μm2　chips　and　then　packaged　into　TO-18　without　epoxy　resin.　With　20-mA\　current　injection,　the　light　intensity　and　output　power　of　LED-I　with　surface　roughening　respectively　reach　315　mcd　and　4.622　mW,　which　was　1.7　times　higher　than　that　of　LED-II　without　surface　roughening.　The　enhancement　of　output　power　in　LED-I　can　be　attributed　to　the　pyramid-like　surface,　which　not　only　reduces　the　total　internal　reflection　at　the　semiconductor-air　interface　but　also　effectively　guides　more　photons　into　the　escape　angle　for　emission　from　the　LED　device.　©　2010　Chinese　Institute　of　Electronics.