Electronics Components: How Integrated Circuits Are Made - dummies

Electronics Components: How Integrated Circuits Are Made

By Doug Lowe

You don’t have to know how integrated circuits (IC) are made to use them in your electronics projects, but the process is pretty interesting The process is complex and varies depending on the type of chip being made. But the following process is typical:

  1. A large, cylindrical piece of silicon crystal is shaved into thin wafers about one-hundredth of an inch thick.

    Each of these wafers will be used to create several hundred or thousand finished integrated circuits.

  2. A special photoresist solution is deposited on top of the wafer.

  3. A mask is applied to over the photoresist.

    The mask is an image of the actual circuit, with some areas transparent to allow light through and others opaque to block the light.

  4. The wafer is exposed to intense ultraviolet light.

    The ultraviolet light etches the wafer under the transparent portions of the mask but leaves the areas under the opaque parts of the mask untouched.

  5. The mask is removed and any remaining photoresist is cleaned off.

  6. The wafer is then exposed to a doping material.

    This creates n-type and p-type regions in the etched areas of the wafer.

  7. The process is repeated for each layer until all of the layers have been created.

    Of course, this assumes that the circuit design calls for multiple layers stacked on top of one another.

  8. The individual integrated circuits are then cut apart and mounted in their final packaging.

Here are a few other tidbits worth knowing about how integrated circuits are made:

  • As you’ve probably seen on Intel commercials, the manufacturing process for integrated circuits is done in a clean room, where workers wear special suits and masks. This is necessary because at the scale of the integrated circuits, even the smallest speck of dust is enormous.

  • Each integrated circuit goes through a variety of complicated quality tests after the circuit is finished. The manufacturing process is by no means perfect, so many are discarded.