Process of Making Microchips

Chips are made in multibillion-dollar fabrication plants called fabs. Fabs melt and refine sand to produce 99.9999% pure single-crystal silicon ingots. Saws slice the ingots into wafers about as thick as a dime and several inches in diameter. The wafers are cleaned and polished, and each one is used to build multiple chips. 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. Some clean rooms are even cleaner than hospital surgical rooms!

Silicon Wafer
Silicon Wafer


Here is how memory chips are made from wafers:

A 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 photoresist is exposed to ultraviolet light shined through a patterned plate, or "mask," which hardens the areas exposed to the light. Unexposed areas are then etched away by hot gasses to reveal the silicon dioxide base below. The base and the silicon layer below are further etched to varying depths.

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 electrical conductivity of certain parts of the chip can also be altered by doping them with chemicals under heat and pressure. 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.

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. Sometimes several layers of conductors, separated by glass insulators, are laid down.

Each chip on the wafer is tested for correct performance and then separated from other chips on the wafer by a saw. Good chips are placed into the supporting packages that allow them to be plugged into circuit boards, and bad chips are marked and discarded

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What are microchips used for?

Microchips are commonly used in electronical devices such as in your computer, thumbdrive or SD cards in cameras. Microchips can help store memory in bytes. In computers, microchips are also used in the Dynamic Random Access Memory (DRAM), NAND and NOR. NAND Flash memory chips is a special form of Flash memory, Flash memory is a memory technology that can keep data even when the power is cut off, otherwise known as non-volatile memory chips. NOR flash memory supports one-byte random access, which allows machine instructions to be retrieved and run directly from the chip, in the same way that a traditional computer will retrieve instructions directly from main memory. NOR flash has an SRAM interface that includes enough address pins to map the entire chip, enabling for access to every byte stored within it.

NOR and NAND are used differently. NOR is more often used in mobile phones because of its small size while NAND is more commonly used in computers because of its storage capacity.

NAND Flash
NAND Flash


NOR Flash
NOR Flash