After　the　longitudinal　structure　of　Si/SiGe　HBT　is　determined,　the　bad　noise　performance　is　mainly　caused　by　the　high　base　resistance　of　the　device,　and　the　large　mesa　area　of　base　or　emitter　leads　to　the　poor　frequency　characteristics.　In　order　to　improve　the　noise　and　frequency　features,　both　the　ion　implantation　and　the　buried　metal　self-aligned　technique　were　used　during　the　fabrication　procedure.　Compared　to　the　traditional　fabrication,　ion　implantation　can　reduce　the　extrinsic　base　resistance,　the　buried　metal　self-aligned　technique　can　decrease　the　contact　resistance　of　the　electrode　lead　and　reduce　the　area　of　the　electrode　mesa.　Basing　on　this,　the　minimum　noise　figure　and　the　cut　off　frequency　of　the　Si/SiGe　HBT　were　tested.　The　results　indicate　that　the　noise　performance　and　frequency　performance　of　the　device　are　improved　apparently　than　before.