Silicon-based　hetero-junction　phototransistor　(HPT)　is　a　potential　optical　detector　promising　for　communication　links　in　optic-interconnect　network　due　to　their　advantages　of　low　cost,　high　internal　gain,　high　sensitivity,　and　compatibility　with　CMOS　processes.　In　this　work,　a　SiGe/Si　HPT　with　double-zone　base　is　designed　and　optimized　to　provide　high　responsivity　and　outstanding　frequency　characteristics　simultaneously.　The　SiGe　HPTs　with　different　window　positions　and　areas　are　fabricated　using　BiCMOS-compatible　mesa　process,　and　the　influence　of　transverse　parameters　on　HPT　performance　is　analyzed　comprehensively.　With　this　design,　a　maximum　optical　responsivity　of　8.52　A/W　and　a　maximum　optical　3　dB　bandwidth　of　638　MHz　are　demonstrated.　The　responsivity　bandwidth　product　achieves　4.69　GHz　&　sdot;A/W　with　50　x　50　mu　m(2)　optical　window　on　emitter　mesa　under　850　nm　incident　light,　which　is　expected　to　be　applied　in　silicon-based　optical　connecting　technology　to　simplify　the　optical　receiving　circuits　and　lower　its　power　consumption.