After　the　shortage　of　the　conventional　lateral　structure　of　SiGe　HBT　was　analyzed,　A　new　lateral　structure　was　presented.　In　the　meantime,　the　new　fabrication　process　named　buried　metal　self-aligned　technique　was　designed.　The　measured　frequency　features　show　that　the　cut-off　frequency　fT　of　the　device　up　to　12.3GHz　and　the　maximum　oscillation　frequency　fmax　achieves　5.7GHz.　Compared　to　the　conventional　lateral　structure　and　process,　the　values　of　fT　and　fmax　SiGe　HBT　based　on　the　new　lateral　structure　and　process　have　been　increased　17%　and　18.75%　respectively.　This　indicates　that　the　new　lateral　structure　and　buried　metal　self-aligned　process　is　effective　to　improve　the　high　frequency　performance　of　SiGe　HBT.　©　2006　IEEE.