RF MEMS

The research focus in this area is on CMOS integrated with low loss RF MEMS & RF passives, and also to establish RF MEMS capability in IME through the demonstration of RF switch, phase shifter and tunable filter, etc. This work is currently targeting at the 10-40 GHz frequency range.

Strategy & Focus

  • Design & simulation of RF MEMS components
  • Wafer transfer technology for heterogeneous material integration

Significant Results

Integration of RF MEMS switch and CMOS IC on organic substrate

Monolithic integration of RF MEMS and CMOS IC has long been a goal for both MEMS and IC industries. This integration would simplify the way to incorporate RF MEMS device into RF system at low-cost while maintaining high performance. Due to its better RF performance over the currently used solid state counterparts - FET or p-i-n diodes, integration of RF MEMS switch with IC enables the implementation of compact RF system of light weight, low power consumption and small size for next generation communication systems. Substrate compatibility was the major issue in the above integration, as RF MEMS switch and CMOS IC require different substrate materials for optimised performances. Integration on high-resistive Si, SOI, GaAs has been demonstrated with marginal RF performance improvement in the RF switches. Direct integration on printed circuit board (PCB) offers unique advantages, but only integration of RF switch with antenna was realised.

IME successfully developed a platform technology for integration of MEMS and CMOS on organic substrate. An integration of RF MEMS switch and CMOS IC was demonstrated on a flexible organic substrate at 8” wafer level. The performance of RF-MEMS switch was significantly improved by the elimination of Si substrate and optimised integrated sequence. Sub-µm (0.15µm) CMOS FETs showed preserved device performance on an organic substrate, similar to that on bulk-Si. This technology demonstrated the feasibility of building high performance, compact RF system on organic substrate for wireless communication applications.

 

(a) (b)

(c)

A platform technology for integrated MEMS and CMOS on organic substrate:
a) Schematic cross-sectional view of integrated RF-MEMS Switch and CMOS IC on organic
(b) Top-view of devices transferred onto 8" FR-4 substrate, stacked RF MEMS/CMOS IC on FR-4 (left) and RF MEMS alone on FR-4 (right)
(c) Perspective SEM picture showing RF MEMS switches integrated with CMOS transistors covered by Si-island on top of FR-4 substrate

Key Publication Titles

  • "Novel monolithic integration of RF-MEMS switch with CMOS-IC on organic substrate for compact RF system," IEEE International Electron Devices Meeting (2006)
  • "RF MEMS Switch Integrated on Printed Circuit Board With Metallic Membrane First Sequence and Transferring", Electron Device Letters (July 2006)
  • "Development of RF MEMS Switch on Flexible Organic Substrate with Wafer Transfer Technology (WTT)," 56th Electronic Components and Technology Conference 2006

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