Zoolied's Silicon Wafer
2022-8-22
What Is A Silicon Wafer Used For?
Silicon Wafers are made from a single crystal of highly pure silicon, typically with less than one part per billion of contaminants. The Czochralski process is the most common method of forming large crystals of this purity, which involves pulling a seed crystal from molten silicon, commonly known as a melt. The seed crystal is then formed into a cylindrical ingot known as a boule.
Elements such as boron and phosphorus may be added to the boule in precise quantities to control the wafer`s electrical properties, generally for the purpose of making it an n-type or p-type semiconductor. The boule is then cut into thin slices with a wire saw also known as a wafer saw. The cut wafers may be polished to varying degrees.
What Is A Silicon Wafer Used For?
A silicon wafer is a thin slice of crystalline silicon commonly used in the electronics industry. Silicon is used for this purpose because it`s a semiconductor, meaning it`s neither a strong conductor nor strong insulator of electricity. Its natural abundance and other properties generally make silicon preferable to other semiconductors such as germanium for making wafers.
The most common dimensions of silicon wafers depend on their application. The wafers used in ICs are round with diameters typically ranging from 100 to 300 millimeters (mm). The thickness generally increases with the diameter and is usually in the range of 525 to 775 microns (μm). The wafers in solar cells are usually square with sides measuring 100 to 200 mm. Their thickness is between 200 and 300 μm, although this is expected to be standardized to 160 μm in the near future.
The production of silicon wafer usually has the following steps
1) long crystal, which can be divided into CZ and FZ, because the fused polycrystalline material will directly contact with the quartz crucible, so the impurities in the quartz crucible will contaminate the fused polycrystalline. The CZ method is suitable for drawing large-diameter (300 mm) silicon wafers, which is the main Semiconductor Silicon Wafer material at present. As the polycrystalline raw materials are not in contact with the quartz crucible, there are few internal defects and low carbon and oxygen content, but the price is expensive and the cost is high. It is suitable for high-power devices and some high-end products.
2) slicing and drawing of the single crystal silicon rod need to cut off the head and tail material, then roll and grind it to the required diameter, cut the flat edge or V groove, and then cut into thin silicon wafer. At present, diamond wire cutting technology is usually used, with high efficiency and good warpage and curvature of silicon wafer. A small number of special shaped pieces can be cut with an inner circle.
3) grinding: after slicing, the damaged layer on the cutting surface needs to be removed by grinding to ensure the quality of the silicon wafer surface, about 50um.
4) corrosion: corrosion is to further remove the damaged layer caused by cutting and grinding, so as to prepare for the following polishing process. Corrosion usually includes alkali corrosion and acid corrosion. At present, due to environmental factors, most of them adopt alkali corrosion. The removal amount of corrosion can reach 30-40um, and the surface roughness can also reach micron level.
5) polishing: polishing is an important process for silicon wafer production. Polishing is to further improve the surface quality of silicon wafer through CMP (chemical mechanical polished) technology, so that it can meet the requirements of chip production. After polishing, the surface roughness is usually RA < 5A.
6) cleaning and packaging: as the linewidth of the integrated circuit is getting smaller and smaller, the requirements for improving the particle size index are getting higher and higher. Cleaning and packaging is also an important process for silicon wafer production. Most particles attached to the surface of silicon wafer > 0.3um can be cleaned by megasonic cleaning, and then the silicon wafer surface can be made by vacuum sealing packaging or inert gas packaging with a plug box free of cleaning The surface cleanliness meets the requirements of IC.
Silicon Wafers are made from a single crystal of highly pure silicon, typically with less than one part per billion of contaminants. The Czochralski process is the most common method of forming large crystals of this purity, which involves pulling a seed crystal from molten silicon, commonly known as a melt. The seed crystal is then formed into a cylindrical ingot known as a boule.
Elements such as boron and phosphorus may be added to the boule in precise quantities to control the wafer`s electrical properties, generally for the purpose of making it an n-type or p-type semiconductor. The boule is then cut into thin slices with a wire saw also known as a wafer saw. The cut wafers may be polished to varying degrees.
What Is A Silicon Wafer Used For?
A silicon wafer is a thin slice of crystalline silicon commonly used in the electronics industry. Silicon is used for this purpose because it`s a semiconductor, meaning it`s neither a strong conductor nor strong insulator of electricity. Its natural abundance and other properties generally make silicon preferable to other semiconductors such as germanium for making wafers.
The most common dimensions of silicon wafers depend on their application. The wafers used in ICs are round with diameters typically ranging from 100 to 300 millimeters (mm). The thickness generally increases with the diameter and is usually in the range of 525 to 775 microns (μm). The wafers in solar cells are usually square with sides measuring 100 to 200 mm. Their thickness is between 200 and 300 μm, although this is expected to be standardized to 160 μm in the near future.
The production of silicon wafer usually has the following steps
1) long crystal, which can be divided into CZ and FZ, because the fused polycrystalline material will directly contact with the quartz crucible, so the impurities in the quartz crucible will contaminate the fused polycrystalline. The CZ method is suitable for drawing large-diameter (300 mm) silicon wafers, which is the main Semiconductor Silicon Wafer material at present. As the polycrystalline raw materials are not in contact with the quartz crucible, there are few internal defects and low carbon and oxygen content, but the price is expensive and the cost is high. It is suitable for high-power devices and some high-end products.
2) slicing and drawing of the single crystal silicon rod need to cut off the head and tail material, then roll and grind it to the required diameter, cut the flat edge or V groove, and then cut into thin silicon wafer. At present, diamond wire cutting technology is usually used, with high efficiency and good warpage and curvature of silicon wafer. A small number of special shaped pieces can be cut with an inner circle.
3) grinding: after slicing, the damaged layer on the cutting surface needs to be removed by grinding to ensure the quality of the silicon wafer surface, about 50um.
4) corrosion: corrosion is to further remove the damaged layer caused by cutting and grinding, so as to prepare for the following polishing process. Corrosion usually includes alkali corrosion and acid corrosion. At present, due to environmental factors, most of them adopt alkali corrosion. The removal amount of corrosion can reach 30-40um, and the surface roughness can also reach micron level.
5) polishing: polishing is an important process for silicon wafer production. Polishing is to further improve the surface quality of silicon wafer through CMP (chemical mechanical polished) technology, so that it can meet the requirements of chip production. After polishing, the surface roughness is usually RA < 5A.
6) cleaning and packaging: as the linewidth of the integrated circuit is getting smaller and smaller, the requirements for improving the particle size index are getting higher and higher. Cleaning and packaging is also an important process for silicon wafer production. Most particles attached to the surface of silicon wafer > 0.3um can be cleaned by megasonic cleaning, and then the silicon wafer surface can be made by vacuum sealing packaging or inert gas packaging with a plug box free of cleaning The surface cleanliness meets the requirements of IC.
