Multi-level interconnects for heterojunction bipolar transistor integrated circuit technologies

[摘要] Heterojunction bipolar transistors (HBTs) are mesa structures which present difficult planarization problems in integrated circuit fabrication. We report a multilevel metal interconnect technology using benzocyclobutene (BCB) to implement high-speed, low-power photoreceivers based on InGaAs/InP HBTs. Processes for patterning and dry etching BCB to achieve smooth via holes with sloped sidewalls are presented. Excellent planarization of 1.9 mu m mesa topographies on InGaAs/InP device structures is demonstrated using scanning electron microscopy (SEM). Additionally, SEM cross-sections of both the multi-level metal interconnect via holes and the base-emitter via heres required in the HBT IC process are presented. All via holes exhibit sloped sidewalls with slopes of 0.4 mu m mu m(-1) to 2 mu m mu m(-1) which are needed to realize a robust interconnect process. Specific contact resistances of the interconnects are found to be less than 6 x 10(-8) Omega cm(2). Integrated circuits utilizing InGaAs/InP HBTs are fabricated to demonstrate the applicability and compatibility of the multi-level interconnect technology with integrated circuit processing.

[发布日期] 1996-12-15

[效力级别]  Proceedings Paper

[关键词] benzocyclobutene;heterojunction bipolar transistors;planarization;multi-level interconnects