Performance of InP/GaAsSb DHBTs Planarized with Teflon AF Compared to DHBTs with Airbridge Interconnects

We compare the DC and RF performance of InP/GaAsSb/InP DHBTs fabricated in a Teflon AF planarization process to identical DHBTs with airbridge interconnects. No statistically significant difference in performance was observed, proving that the Teflon AF layer does not degrade the devices. Multi-layer deposition and dry etching of Teflon AF were investigated to explore the suitability of Teflon AF as an interlevel dielectric in DHBT based MMICs.