Improved power linearity of InGaP/GaAs heterojunction bipolar transistors (HBTs) with collector design is reported. The collector design is based on nonuniform collector doping profile which is to employ a thin high-doping layer (5 × 1017 cm-3/200 A) inside the collector (1 × 1016 cm-3/7000 Å). The additional thin high-doping layer within the collector shows no obvious effects and impacts in dc characteristics and device fabrication if the layer was inserted close to the subcollector. For an HBT with a thin high-doping layer being inserted 4000 Å from the base-collector junction, the experimental result on third-order intermodulation demonstrates the significant reduction by as large as 9 dBc and improved IIP3 by 5 dB under input power of -10 dBm at frequency of 1.8 GHz.
|Number of pages||3|
|Journal||IEEE Electron Device Letters|
|State||Published - Feb 2004|
- Heterojunction bipolor transistor (HBT)