Experimental Characterization of the Effect of Metal Dummy Fills on Spiral Inductors

Abstract

In modern CMOS technologies, metal dummy fills are required to maintain metal density uniformity and to planarize the layers. As frequency increases, the effect of the metal dummy fills on the CMOS integrated circuits or components should be taken into account. This work presents experimental results of the effect of metal dummy fills on the microwave behavior of spiral inductors fabricated in a standard 0. 18-µm CMOS technology. The influences on the equivalent model parameters and the Q-factor are characterized based on measured S-parameters of inductors with and without metal dummy fills.Index Terms -CMOS technology, chemical-mechanical polishing process (CMP), metal dummy fills, microwave measurements, spiral inductors.

A Thru-Only De-Embedding Method Foron-Wafer Characterization of Multiport Networks

“…One Fig. 1(b) In particular, hardly any justification has been given for the validity of the Π-equivalent-based bisecting of the THRU Laney, 2003;Nan et al, 2007;Song et al, 2001;Tretiakov et al, 2004a). There are other possible ways of bisecting the THRU.…”

“…The high cost associated with the large area required for dummy patterns is a drawback of advanced de-embedding methods. Thru-only methods, in contrast, require only one THRU and gaining popularity (Daniel et al, 2004;Goto et al, 2008;Laney, 2003;Nan et al, 2007;Song et al, 2001;Tretiakov et al, 2004a). In Laney, 2003;Nan et al, 2007;Song et al, 2001;Tretiakov et al, 2004a), the THRU is modeled by a Π-type equivalent circuit shown in Fig.…”

“…1(b) is negligible (Goto et al, 2008;Rautio, 1991). In what follows, we will focus on the method of Laney, 2003;Nan et al, 2007;Song et al, 2001;Tretiakov et al, 2004a). The THRU pattern used in ) is shown in Fig.…”

“…4 shows good agreement between the measurement data and the model up to 100 GHz. The procedure of the thru-only de-embedding method ( Laney, 2003;Nan et al, 2007;Song et al, 2001;Tretiakov et al, 2004a)) is as follows. The 2-port containing the DUT and the THRU a are assumed to be representable by Fig.…”

“…5 shows that those do hold approximately. Published papers indicate reasonable success of the thru-only de-embedding method for 2-ports Laney, 2003;Nan et al, 2007;Song et al, 2001;Tretiakov et al, 2004a).…”