Ferroelectric Dielectrics Integrated on Silicon

Chapter 10Ferroelectric Tunable Capacitors ¹

 

 

 

10.1. Introduction

In terms of innovation, the emerging microelectronic technologies have advocated in recent years the proliferation of features within smaller and smaller devices. The most striking example is undoubtedly that of mobile telephony. Laptops manufactured nowadays offer the access to new features that coexist with their primary utility: radio, MP3 player, calendar, GPS, camera, camcorder, television, etc.

In addition, as a communication device, a modern mobile phone has the constraint of having to adapt to different environments (variations of network power, temperatures, changes in telephony standards according to the country, etc.).

Manufacturers of mobile devices have, therefore, been forced to supply more versatile components in recent years. In particular, they chose to replace the bulky passive components of integrated circuits by tunable elements. One possibility being considered in this regard is to use the properties of ferroelectric materials to obtain such components. This is what we intend to detail in this chapter through three sections:

– general issue on the tunable capacitors and state of the art;

– the two families of ferroelectric tunable capacitors: metal–insulator–metal (MIM) and planar; and

– innovative architectures of tunable capacitors.

Ferroelectric Dielectrics Integrated on Silicon

10.2. Overview of the tunable capacitors

10.2.1. Applications requiring a tunable element

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