Demonstration of a 3-D GaAs HEMT Phase Shifter MMIC Utilizing a Five Layer BCB Process with Seven Metal Layers

In this paper, we demonstrate a vertically integrated 3-D MMIC phase shifter at 8 GHz that utilizes a 5-layer benzocyclobutene (BCB) process providing a total of 7 metal layers. This multi-layer technology is fully compatible with Northrop Grumman's 0.15 um GaAs HEMT technology and enables a high level of MMIC compaction which will substantially reduce the size and cost of MMICs. A key feature of this technology is the ability to isolate vertically integrated components of a MMIC' with separate ground planes allowing circuit compaction while maintaining high isolation.