Title :
A multilayer circuit technology for GaAs MMICs
Author :
Donahue, R.S. ; Putnam, J. ; Tajadod, J.
Author_Institution :
M/A-COM Adv. Semiconductor Div., Lowell, MA, USA
Abstract :
A multilayer circuit technology using a layer of polyimide on the top surface of a GaAs MMIC (monolithic microwave IC) is presented. The circuit ground plane is located on top of this coating of polyimide and miniature low inductance vias to ground are etched through the photosensitive polyimide to the top surface of the GaAs substrate. The removal of vias in the GaAs substrate allows the wafer backside processing steps to be eliminated, leaving the GaAs substrate relatively thick. Also, selective patterning of the ground plane affords an added degree of design flexibility. The feasibility of the process is demonstrated using a single-bit phase shifter which is translated to the new medium. Results for the X-band phase shifter in both the original microstrip and the new topology are presented. Data for nonhomogeneous asymmetric transmission lines are also detailed.<>
Keywords :
III-V semiconductors; MMIC; gallium arsenide; integrated circuit technology; polymer films; GaAs; GaAs substrate; X-band phase shifter; circuit ground plane; miniature low inductance vias; monolithic microwave IC; multilayer circuit technology; nonhomogeneous asymmetric transmission lines; polyimide; selective patterning; Coatings; Gallium arsenide; Inductance; MMICs; Microwave integrated circuits; Microwave technology; Monolithic integrated circuits; Nonhomogeneous media; Phase shifters; Polyimides;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1990. Technical Digest 1990., 12th Annual
Conference_Location :
New Orleans, LA, USA
DOI :
10.1109/GAAS.1990.175498
