| 摘要 |
PURPOSE: A method for fabricating a heterojunction bipolar transistor(HBT) is provided to easily fabricate a bipolar complementary metal oxide semiconductor(BiCMOS) device employing CMOS and HBT by simplifying the process for forming a SiGe HBT and by simultaneously embodying the CMOS and the HBT. CONSTITUTION: An N+ silicon epi-layer(22) and an N- silicon epi-layer(23) are sequentially grown on a substrate(21). The N- silicon epi-layer, the N+ silicon epi-layer and the substrate are etched to form the first trench. Silicon is filled in the first trench. Predetermined portions of the N- silicon epi-layer including the first trench portion are etched to form the second trenches. An oxide layer is filled in the second trenches. An ion implantation mask exposing a collector formation region is formed on the N- silicon epi-layer. N-type impurity ions are implanted into the exposed region to form a collector region(27). A SiGe layer(28) and a silicon epi-layer(29) are sequentially formed on the exposed N- silicon epi-layer region except the collector region. A polysilicon layer(30) and a tetraethoxysilane(TEOS) layer are sequentially formed. The TEOS layer, the polysilicon layer, the silicon epi-layer and the SiGe layer are patterned to form an emitter(32) on the N- silicon epi-layer region. P-type impurity ions are implanted into the N- silicon epi-layer region at both sides of the emitter to form a base region(34). The TEOS layer is removed and a spacer is formed on both sidewalls of the emitter. Metal silicide(36) is formed on the collector region, the base region and the emitter.
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