“Slice” or “Substrate”, in other words WAFER!

A wafer, also called a slice or substrate. It is actually a thin piece of semiconductor material, such as a crystalline silicon. It is mostly used in electronics for the fabrication of integrated circuits and in photovoltaics for conventional, wafer-based solar cells. The wafer serves as the substrate for microelectronic devices. Today silicon chips are everywhere. Some microfabrication process step like doping or ion implantation, etching, deposition of various materials, and photolithographic patterning are applied. . Finally the individual microcircuits are separated (dicing) and packaged.

Wafers are formed of highly pure (99.9999999% purity), nearly defect-free single crystalline material. Ultrabook devices, smartphones, tablets, high performance computing, data centers included this material. Engineers automate factories and are embedded in automobiles and everyday devices. The most sophisticated processor can contain hundreds of millions or billions of transistors interconnected by fine wires made of copper. Each of these transistors acts as an on/off switch, controlling the flow of electricity through the chip to send, receive, and process information. Wafers today may have multiple cores.

http://nanografi.com/blog/slice-or-substrate-in-other-words-wafer/