Front-end manufacturing is the process of fabricating a chip’s design onto a raw wafer to yield a die.
The process of semiconductor manufacturing consists of the steps listed below. These steps can be repeated several hundred times to yield a semiconductor fabricated wafer.
- Oxidation adds thin layers onto the wafer to form microstructures. New layers can function as an insulator, a conductor, or a protective barrier. Different methods—like spraying metals, gases, or using plasma—are used to apply new materials.
- Photolithography works like stenciling new patterns with light. A light-sensitive coating is spread onto the wafer, then ultraviolet light shines through a patterned mask. The light hardens or softens the exposed areas, leaving a designed surface.
- Doping changes electrical conductivity in specific parts of the wafer by applying impurities. Beams of special atoms are implanted into select spots, then heat locks those changes. These treated areas will become the “on” and “off” switches for future transistors.
- Thin Film Deposition creates extremely thin layers of material on the surface of a substrate. These films provide electrical, optical, mechanical, and chemical functionality to the surface.
- Metalization creates electrical interconnections between a wafer’s transistors. The process relies on a variety of techniques to deposit different types of barrier or conductive layers.
- Etching removes the unwanted material left after photography. Liquids or plasma carve out the pattern and leave behind the patterned circuitry. The wafer is then cleaned and smoothened to ensure the next layer can be added.
- Chemical mechanical planarization uses chemical and physical forces to yield a perfectly flat surface ready for the next layer of circuitry. After deposition or etch processes, a pad or slurry solution is used to polish the surface and thereby remove undesired materials.
- Metrology is the quality control for chipmaking. After each layer is deposited, inspection tools check for defects by measuring the wafer thickness, alignment, and features. These inspections detect and allow for problems to be fixed before more layers are added.
If you are interested in learning more about semiconductor manufacturing, please refer to our Chemistry of Semiconductors video series.
