Chemical Mechanical Planarization of Microelectronic Materials

Why CMP?

“…Among all these techniques, CMP is the only one that can offer excellent local and global planarities at the same time. More specifically, CMP can yield local planarization of features in the order of tens of microns and near-global planarization as far as tens of millimeters [5,20].…”

“…In a state-of-the-art integrated circuit, there are many active and passive elements including millions of transistors, capacitors, and resistors on a single chip [5]. In this ultra-large-scale integration (ULSI) era, the number of transistors per chip has already crossed the 40 million mark and is expected to increase to more than a billion over the next decade [6].…”

“…This leads to a significant reduction in signal processing delays and improvement in chip performance (see Section 1.3.1 for details). Figure 1.1 shows a cross section of such a multilevel interconnect network in which metal lines are isolated by the dielectric and connected by vertical vias [5,7]. It is noted that the metal lines on the lower levels are much narrower in order to match the dimensions of the transistors and other microstructures.…”

“…To meet the requirement set by the depth of focus for subquarter micron technology, the roughness to be eliminated is in the regime of nanotopography and microwaviness. In other words, the step height of interest has an average wavelength of several microns to millimeters [1,5,[20][21][22][23]. Similarly, depending on the net effectiveness on various types of topography, planarization processes can also be categorized as smoothing, local, and global planarizations.…”

“…Soon the technique also enabled the implementation of copper as a better electric conductor, ending more than 40 years of monopoly of aluminum as an interconnect [4]. Since the publication of the first book dedicated to this topic in 1997 [5], the field has been flourished with innovations, discoveries, breakthroughs, and successful implementations. Part of this book will cover the new breakthroughs and discoveries with an emphasis on the chemistry behind the processes and the materials used in the applications.…”