In　this　Letter,　a　Ga2O3　vertical　Schottky　barrier　diode　(SBD)　with　self-aligned　field　plate　and　mesa　termination　is　fabricated　and　studied.　The　combination　of　field　plate　and　mesa　termination　can　effectively　make　the　electric　field　distribution　uniform　in　the　termination,　and　thus　the　proposed　SBD　features　high　breakdown　voltage　(BV).　Moreover,　to　eliminate　alignment　deviation　and　simplify　the　fabrication　process,　a　self-aligned　etching　process　is　developed.　The　experimental　results　show　that　a　low　specific　on-resistance　of　4.405　m　Omegacm(2)　and　a　high　BV　of　3113　V　can　be　simultaneously　derived　on　the　proposed　SBD,　yielding　a　high　power　figure　of　merit　of　2.2　GW/cm(2).　Meanwhile,　a　considerably　low　forward　voltage　of　1.53　V　at　100　A/cm(2)　is　also　achieved,　demonstrating　the　low　conduction　loss　of　the　device.