The complete process of chip production includes chip design, chip production, package production, cost testing and other links, among which the chip production process is particularly complex. The first is the chip design, according to the design needs, the generated \"pattern\"
1, the raw material of the chip wafer wafer composition is silicon, silicon is refined by quartz sand, the wafer is the silicon element to be purified (99.999%), and then these pure silicon into silicon rods, become the material of quartz semiconductor manufacturing integrated circuit, the chip is the specific wafer required for chip production. The thinner the wafer, the lower the cost of production, but the higher the requirements for the process.
2, wafer coating wafer coating can resist oxidation and temperature resistance, the material is a kind of photoresistance.
3. Wafer lithography development and etching The process uses chemicals that are sensitive to ultraviolet light, that is, they become soft when confronted with ultraviolet light. The shape of the chip can be obtained by controlling the position of the shade. Silicon wafers are coated with photoresist so that they dissolve when exposed to ultraviolet light. At this time, the first shade can be used, so that the part of the ultraviolet light is dissolved, which can then be washed away with a solvent. So the rest of the piece is in the same shape as the shade, which is exactly what we want. This gives us the silica layer we need.
4. Add impurities to implant ions into the wafer to generate corresponding P and N class semiconductors. The specific process is to start from the exposed area on the silicon wafer and put it into a chemical ion mixture. This process will change the way the doped zone conducts electricity, so that each transistor can be on, off, or carry data. Simple chips can use only one layer, but complex chips often have many layers, and this process is repeated over and over again, and the different layers can be connected by opening a window. This is similar to the production principle of multi-layer PCB board. More complex chips may require multiple layers of silica, which can be achieved through repeated lithography and the above process to form a three-dimensional structure.
5, wafer test After the above several processes, a lattice grain is formed on the wafer. The electrical characteristics of each grain were detected by means of needle measurement. Generally, the number of grains per chip is huge, and organizing a pin test mode is a very complex process, which requires the production of a large batch of models with the same chip specifications as far as possible. The larger the quantity, the lower the relative cost, which is also a factor why the mainstream chip device cost is low.
6, packaging will be manufactured to complete the wafer fixed, binding pins, according to demand to make a variety of different packaging forms, which is the same chip core can have different packaging forms of reason. For example: DIP, QFP, PLCC, QFN and so on. This is mainly determined by the user's application habits, application environment, market form and other peripheral factors.
7, testing, packaging After the above process, the chip production has been completed, this step is to test the chip, remove the defective products, and packaging.