Open AccessMulti-level interconnects for heterojunction bipolar transistor integrated circuit technologies
Author(s) -
G A Patrizi,
M L Lovejoy,
Jr Schneider,
H.Q. Hou,
P.M. Enquist
Publication year - 1995
Language(s) - English
Resource type - Reports
DOI - 10.2172/212553
Subject(s) - chemical mechanical planarization , materials science , heterojunction bipolar transistor , optoelectronics , interconnection , benzocyclobutene , bipolar junction transistor , common emitter , integrated circuit , heterojunction , fabrication , etching (microfabrication) , transistor , electrical engineering , nanotechnology , computer science , engineering , voltage , layer (electronics) , medicine , alternative medicine , pathology , dielectric , computer network
Heterojunction bipolar transistors (HBTs) are mesa structures which present difficult planarization problems in integrated circuit fabrication. The authors 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 {micro}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 holes required in the HBT IC process are presented. All via holes exhibit sloped sidewalls with slopes of 0.4 {micro}m/{micro}m to 2 {micro}m/{micro}m which are needed to realize a robust interconnect process. Specific contact resistances of the interconnects are found to be less than 6 {times} 10{sup {minus}8} {Omega}cm{sup 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