Silicon wafer
Silicon wafer is one of the most widely used semiconductor materials. It is used to create transistors, integrated circuits and microprocessors for use in many consumer and industrial electronics, as well as in other electronic products. Silicon wafer is made of crystalline silicon, which is highly electrically conductive and thermally stable. The surface of a silicon wafer is typically used to create the desired pattern of transistors and other electronic circuit components.
Silicon wafer is formed by cutting a large block of crystalline silicon into thin slices. Each slice is called a wafer, and each wafer has a specific number of grains or crystals in it. These grains act like tiny electronic switches, controlling how electricity flows through the silicon wafer. Silicon wafers come in a variety of shapes and sizes, and are typically used for large-scale production of components for silicon-based electronics.
Silicon wafers come in either single-crystal or poly-crystalline form. Single-crystal silicon wafers are made from a single large crystal of silicon, and are the most efficient form of wafer when used to make transistors and other device components. However, due to the difficulty in creating single-crystal wafers, poly-crystal silicon wafers are more commonly used in consumer electronics. The advantage of poly-crystalline silicon is that it can be cut into slices with relatively few imperfections or grain boundaries, as opposed to single-crystal silicon which can be too difficult to machine.
Silicon wafer is designed to be as thin and uniform as possible, so that it can take up minimal space on a circuit board, while still conducting electricity efficiently. The typical thickness of a silicon wafer is between 75-150 microns (0.003 to 0.006 inches). Wafers are polished to ensure that their surfaces are as flat and smooth as possible, with minimal outward curvature or undulations.
In addition to the materials used to make silicon wafers, there are also processes used to refine them and make them usable for creating electronics. The most common processes for refining silicon include oxidation, diffusion and etching. Oxidation is the process by which a layer of silicon dioxide is deposited onto the wafer, creating an insulator to separate transistors from each other and prevent unwanted electrical currents from passing between them. Diffusion is the process by which dopant atoms are introduced into the surface of the wafer. Doping helps to control the flow of electricity and thus the performance of transistors and other circuit components. Etching is the process by which features are created on the wafer, allowing circuit components to be connected and wires to be soldered.
The silicon wafer industry is highly competitive. Some of the key players in the industry include Shin-Etsu, Tokyo Electron and IQE PLC. Companies such as Intel and AMD produce their own silicon wafers or purchase them from outside manufacturers. The cost of a silicon wafer is largely dependent on the quality and complexity of its surface. The complexity of the surface affects the cost and feasibility of producing the desired device, while the quality and efficiency of the wafer can affect the performance of the device.
