High-isolation bonding pad design for silicon RFIC up to 20 GHz

A simple depletion-insulation (DI) bonding pad structure is presented for silicon radio frequency integrated circuits (RFIC). Experimental results show that DI bonding pads can achieve a 3 to 7 dB improvement in cross-talk isolation compared with an ordinary bonding pad at all measured frequencies. An improvement of up to 90% in the Q-factor is also achieved by the DI pad indicating a significantly reduced high-frequency substrate loss. When compared with a ground-shield (GS) bonding pad, the isolation and the Q-factor of the DI bonding pad is inferior. However, the DI pad has a 40% smaller pad capacitance compared with the GS pad. The DI structure can be used in interconnect optimization to achieve high cross-talk isolation and low substrate loss, with minimal increase in parasitic capacitance.

[1]  K. Mizuno,et al.  Analog CMOS integrated circuits for high-temperature operation with leakage current compensation , 1998, 1998 Fourth International High Temperature Electronics Conference. HITEC (Cat. No.98EX145).

[2]  R. Collin.  Foundations for microwave engineering , 1966 .

[3]  J. Colvin,et al.  Effects of substrate resistances on LNA performance and a bondpad structure for reducing the effects in a silicon bipolar technology , 1999 .

[4]  Ashok V. Krishnamoorthy,et al.  Optoelectronic-VLSI: photonics integrated with VLSI circuits , 1998 .

[5]  N. Camilleri,et al.  Bonding pad models for silicon VLSI technologies and their effects on the noise figure of RF NPNs , 1994, Proceedings of 1994 IEEE Microwave and Millimeter-Wave Monolithic Circuits Symposium.

[6]  On-chip spiral inductors with patterned ground shields for Si-based RF ICs , 1998 .

[7]  Changmo Sung.  Material and device characterization to improve yield and performance , 1995, Proceedings of Electro/International 1995.

[8]  Scott A. Wartenberg.  RF measurements of die and packages , 2002 .

[9]  R. C. Frye.  Integration and electrical isolation in CMOS mixed-signal wireless chips , 2001 .

[10]  Denis Flandre,et al.  Substrate crosstalk reduction using SOI technology , 1997 .

[11]  Yuan Taur,et al.  Fundamentals of Modern VLSI Devices , 1998 .

[12]  Behzad Razavi,et al.  Design of Analog CMOS Integrated Circuits , 1999 .

[13]  S. Campbell.  The Science and Engineering of Microelectronic Fabrication , 2001 .

[14]  C. Yue,et al.  On-chip Spiral Inductors With Patterned Ground Shields For Si-based RF IC's , 1997, Symposium 1997 on VLSI Circuits.

[16]  Cheon Soo Kim,et al.  Gate layout and bonding pad structure of a RF n-MOSFET for low noise performance , 2000, IEEE Electron Device Letters.

[17]  D. Schroder.  Semiconductor Material and Device Characterization , 1990 .

[18]  T. E. Kolding.  Shield-based microwave on-wafer device measurements , 2001 .

[19]  D. J. Allstot,et al.  Computer-aided design considerations for mixed-signal coupling in RF integrated circuits , 1998 .