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• Silicon is the basic material of a chip, which is a small piece of matter inside an electronic device.
• Silicon has crystalline defects.
• Silicon is the structure of an electronic device.
• A silicon wafer is obtained through polycrystalline silicon.
• Silicon is inside the single crystal.
• Silicon is doped.
• Silicon is available in great abundance on the Earth, making up approximately 40% of the Earth's crust.
• Silicon does not occur naturally in its elemental state, but in compound forms such as silicates and quartz.
• Quartz is the primary source of silicon in the semiconductor industry.
• Silicon has crystalline defects.
• Silicon is doped.
• Silicon is the structure of a single crystal.
• Silicon is obtained from polycrystalline silicon.
• Silicon is inside the single crystal.
• Due to the increase in concentration in the melt, the dopant concentration increases in the crystal as well.
• The dopant is added to the polysilicon charge or melt in the crucible.
• Element segregation coefficient is a ratio of concentrations of the dopant in the two phases.
• Most of elements have segregation coefficient less than unity, meaning only a part of dopant is integrated into the crystal.
• Carbon has much lower concentration than oxygen in the crystal.
• During the cropping of the crystal, a few thin slices are removed for testing.
• Wafer manufacturing involves processes such as wafer edge grinding, double-sided lapping, stress relief etching, etching machine backside treatment, CVD equipment, polishing, and chemical cleaning.
• Between the two phases, redistribution of the dopant takes place.
• The dopant concentration in the crystal will be the lowest at the top end and the highest at the bottom end of the ingot.
• In the crystal growth process, there are two phases at the interface - the solid crystal and the liquid melt.
• Knowing the orientation, the position of the flat is accurately determined by X-ray diffraction.
• The rest of the dopant is rejected back into the melt, resulting in dopant accumulation in the melt as crystal growth proceeds.
• Silicon is the main component of a silicon wafer.
• The cropped ingot is placed in the grinding machine and the machine grinds down the crystal until the target diameter of the cylinder is reached.
• Traces of other impurities are also present in the crystal.
• Heavy metals have very low segregation coefficients which results in further material purification.
• The concentration of these impurities is lower than that of carbon and they accumulate in the melt residue left in the crucible.
• Silicon is obtained from polycrystalline silicon.
• Ingot shaping and testing involves cutting the pulled ingot into individual sections, examining for defects, removing the ends of the ingot, and removing a few thin slices for testing.
• If the wafer material is doped and it is P or N-type then the crystallographic orientation, in respect to the silicon wafer surface, is important for the wafer properties.
• The conductivity (P or N) type and a silicon wafer crystallographic orientation are encoded in a relative position of primary and secondary flat on each wafer.
• A 100 mm wafer is about half a millimeter thick.
• A defect can influence the electrical and mechanical properties of a crystal.
• Many chips are processed together in one slice of semiconductor - silicon wafer.
• In practice, the orientations according to the pictures are used and they are classified as <111> or <100>.
• Silicon crystallographic structure is diamond type lattice.