High-Q Transformers in Copper-Interconnection CMOS Technology

Abstract

This paper proposes the adoption of aluminum-pad (AL-pad) film to improve the performance of on-chip transformers using current CMOS technology. Two devices proposed in this paper use an AL-pad film, without adding extra process, to enhance the Q value and bandwidth in the copper-interconnection process. The first device changes the transformer's coil location to increase the peak Q value and operation bandwidth, and the second device alters the coil material to improve the Q value in the entire operating band. A foundry 0.13-mu m CMOS technology is fabricated the proposed transformers. The measurement results demonstrate that the first proposed device improves the peak Q value and operation bandwidth with the values of 32.5% and 22.6%, respectively. Afterward, the second proposed device increases the peak Q value 44.7% more than the standard device.