Silicon / Cellulose Wafers List
With the rapidly development of information technology, the importance of silicon wafers becomes more and more prominent, which is the raw material for making transistors and integrated circuits. Various semiconductor devices can be made by means of photolithography and ion implantation of silicon wafer. The main element of silicon wafer is silicon. Because silicon is one of the most abundant elements in the earth's crust, it is possible to prepare silicon wafer on a large scale. Cellulose wafer is a kind of rod-shaped crystal with particle size generally between 30 nm and 100 nm, which can be dispersed in water to form a stable suspension.
Applications:
- Silicon wafers: The applications of silicon wafers mainly focus on semiconductor field and photovoltaic field.
- Semiconductor field: Semiconductor grade silicon wafer has high requirements on the smoothness, and cleanliness of the surface. Silicon wafer is the beginning of the semiconductor industry chain, which runs through the front and back processes of chip manufacturing. As the key materials for chip manufacturing, the production and quality of silicon wafers restrict the development of the whole semiconductor industry and many other industries downstream, such as communication, automobile and computer.
Figure 1. An example of silicon wafer used in semiconductor field.
- Photovoltaic field: Photovoltaic power generation is based on the principle of photovoltaic effect. Photovoltaic devices can effectively utilize solar energy to alleviate energy crisis. As the key component, Silicon wafer plays an important role in the performances of photovoltaic devices.
Figure 2. Schematic diagram of solar cell structure based on silicon wafer.
- Cellulose wafers: Due to the small particle size and large specific surface area, cellulose wafers have some unique optical properties, rheological properties and mechanical properties, and they have been widely used in many fields.
- Nanocomposite field: Cellulose wafers can be used as natural and novel reinforcing agents in the field of nanocomposites. New nanocomposites can be obtained by adding cellulose wafers into the matrix materials. The properties of the nanocomposites largely depend on cellulose wafer morphology, matrix properties and the interaction between cellulose wafer and matrix.
- Pulp and paper industry field: With the advantages of large specific surface area and rich surface hydroxyl, cellulose wafers can be added into the pulp to improve the binding force between the pulp fibers. Therefore, cellulose wafers have a good development prospect as a reinforcement, retention aid and filter aid in pulp and paper industry field.
- The others: The water suspension of cellulose wafers can form a stable colloidal liquid under the action of strong shear force, which is used as a highly effective additive in medicine, food, cosmetics and cement. In addition, cellulose wafers have emulsification and thickening function, and can withstand high and low temperature, which can replace cream to reduce the calories of dairy products. Furthermore, after chemical modification, cellulose wafers can be used as a new type of fine chemical product in the filling material of liquid chromatography separation column.
Classification:
According to the diameter, silicon wafers can be divided into 3 inches, 4 inches, 6 inches, 8 inches, 12 inches (300 mm) and 18 inches (450 mm) silicon wafers. The larger the diameter, the more integrated circuit chips that can be made in a single process cycle on a silicon wafer, and the lower the cost per chip. Therefore, larger diameter silicon wafer is the development direction of various silicon wafer manufacturing technologies. However, the larger the silicon wafer size is, the higher the requirements of microelectronic process equipment, materials and technology will be.
References
- Takaaki Kakitsuka, Takuro Fujii, Koji Takeda, et al. Lateral Current-injection Membrane Lasers Fabricated on a Silicon Substrate[J]. NTT Technical Review, 2016, 14(1):1-7.
- Zin N, Blakers A, Mcintosh K R, et al. Continued Development of All-Back-Contact Silicon Wafer Solar Cells at ANU[J]. Energy Procedia, 2013, 33(1):50-63.
