In　order　to　weaken　the　lattice　self-heating　effect　of　strained-Si　HBT　with　vertical　substrate,　a　trapezoid　Ge　doping　profile　in　base　is　proposed　and　the　device　model　is　established　with　SIL　VACO　TCAD.　It　is　shown　that　temperature　coefficient　of　the　device　is　decreased,　which　is　benefit　for　high　power　application,　at　the　expense　of　the　decrease　of　the　current　gain.　Therefore,　a　further　design　of　superjunction　collector　structure　is　presented　to　enhance　the　breakdown　voltage　which　is　irrelevant　to　the　current　gain.　As　a　result,　the　product　of　current　gain-breakdown　voltage　in　the　novel　strained-Si　HBT　with　vertical　substrate　is　1.61　times　higher　that　the　conventional　device,　which　develops　the　high　power　application　of　SiGe　HBTs.