Making a cpu transistor12/29/2023 ![]() Sometimes several layers of conductors, separated by glass insulators, are laid down.Įach chip on the wafer is tested for correct performance and then separated from other chips on the wafer by a saw. To create conducting paths between the components etched into the chip, the entire chip is overlaid with a thin layer of metal - usually aluminum - and the lithography and etching process is used again to remove all but the thin conducting pathways. Photolithography using different masks, followed by more etching and doping, can be repeated hundreds of times for the same chip, producing a more complex integrated circuit at each step. The electrical conductivity of certain parts of the chip can also be altered by doping them with chemicals under heat and pressure. The photoresist hardened by this process of photolithography is then stripped away, leaving a 3-D landscape on the chip that replicates the circuit design embodied in the mask. The base and the silicon layer below are further etched to varying depths. ![]() Unexposed areas are then etched away by hot gasses to reveal the silicon dioxide base below. The photoresist is exposed to ultraviolet light shined through a patterned plate, or "mask," which hardens the areas exposed to the light. These and subsequent steps are done in a "clean room" environment, where extensive precautions are taken to prevent contamination by dust and other foreign substances.Ī nonconducting layer of silicon dioxide is grown or deposited on the surface of the silicon wafer, and that layer is covered with a photosensitive chemical called a photoresist. The wafers are cleaned and polished, and each one is used to build multiple chips. Saws slice the ingots into wafers about as thick as a dime and several inches in diameter. Fabs melt and refine sand to produce 99.9999% pure single-crystal silicon ingots. Application-specific integrated circuits are special-purpose chips used in things such as cars and appliances.Ĭhips are made in multibillion-dollar fabrication plants called fabs. Digital signal processors convert between analog and digital signals (QuickLink: a2270). ![]() Microprocessors are logic chips that perform the computations inside most commercial computers. Several types of microchips are made today. Transistors can also act as switches - on/off devices used in combination to represent the Boolean operators "and," "or" and "not." These characteristics make it an ideal material for making transistors, which are simple devices that amplify electrical signals. Silicon's electrical properties can be altered by the addition of impurities, a process called doping. ![]() Under some conditions, it conducts electricity under others, it acts as an insulator. ![]()
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |