RF power characteristics of SiGe heterojunction bipolar transistor with high breakdown voltage structures

The collector profile dependences of RF power characteristics of SiGe HBT have been studied. A selectively ion implanted collector (SIC) structure with a thick and lightly doped collector layer showed good RF power characteristics including the adjacent-channel-power-ratio characteristics for middle class power around output power of 16 dBm while maintaining BV/sub CEO/ over 5 V. The maximum BVCEO of 9 V was obtained using the same process only by removing the SIC structure. Both structures are available to fabrication of multi-stage RF power amplifier on to one chip by single process.