Wafer Manufacturing

4Wafer Slicing Using a Modern Slurry Wiresaw and Other Saws

4.1 Introduction

This chapter begins a series of presentations on wafer forming after crystal growth. The first post‐growth wafer forming process is the slicing of ingot into wafers. Today, wafer slicing is performed by various types of saws, including, but not limited to, inner‐diameter (ID) saws, modern slurry wiresaws, and diamond‐impregnated wiresaws. In fact, the majority of current wafer slicing is performed using wiresaws, which will thus be the focus of this chapter.

A saw that utilizes wire as a machining tool is not a new technology. Such saws were used beginning in 19th century Europe on slab stones; the carpenter's wiresaw utilized a steel wire with notches as a cutting tool to carve through wood workpieces. The modern slurry wiresaw, in contrast, is quite different from wiresaws used centuries ago. The modern wiresaw is employed to produce semiconductor prime wafers and photovoltaic (PV) wafers, which require more rigorous processes and stringent requirements of the surface quality (a few microns of surface variation, or less). Modern microelectronics fabrication became a leading industry in the second half of the 20th century, and products using microelectronic chips create many consumer electronics in the 21st century, including PCs, laptops, tablets, and smart phones. Prime wafers, a product of wafer manufacturing, as discussed in Chapter 2, are an essential part of modern microelectronics fabrication. ...