Thin-film MCM-D technology with through-substrate vias for the integration of 3D SiP modules

Abstract

In this paper we present the integration of high-quality passive components and circuits within a thin-film technology on high-resistivity silicon. 100 μm thick wafers are used, allowing the integration of though-silicon vias with a diameter of 100 μm and the implementation of high-quality passive components in a microstrip configuration. Integrated high-density capacitors (650 pF/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), resistors and high-Q inductors are available in this technology. Microstrip lines integrated on the thin high-resistivity silicon present a quality factor 2.5 times higher than coplanar waveguide lines with similar dimensions on AF45 glass, highlighting the advantages of using microstrip type of circuits. High-quality bandpass filters ranging from RF to millimeter-wave frequencies are demonstrated in this technology. A 5.2 GHz lumped element filter as well as coupled lines filters around 30, 50, 60 and 77 GHz providing low losses and a high level of miniaturization are presented. A vertical RF interconnection that brings an RF signal from the front side of the wafer to the backside of the wafer is demonstrated by using the through silicon vias, presenting a loss of about 0.1 dB at 40 GHz. Being able to integrate high-quality passive components at various frequencies and low-loss vertical RF interconnections, this technology is a powerful platform for the integration of high performance 3D system in a package modules.