Chemical Etching Chemical etching is a process used in VLSI design to remove material from silicon wafers to create circuits and interconnects. This is achie...
Chemical etching is a process used in VLSI design to remove material from silicon wafers to create circuits and interconnects. This is achieved by applying a chemical solution to the silicon, which selectively dissolves the material to be removed.
The process is typically used to define the circuitry on a chip, and can also be used to remove unwanted features or patterns from the silicon. Chemical etching is a very precise process, and can be used to create extremely thin and complex circuits.
Chemical etching is a versatile process that can be used to create a wide variety of circuits, from simple resistors and capacitors to complex integrated circuits (ICs). The exact chemicals used in chemical etching will depend on the material being etched and the desired circuit.
Here are some examples of chemical etching:
Silicon chip fabrication: Chemical etching is used to create the circuits on a silicon chip. The silicon wafer is first cleaned and coated with a photoresist, which is a light-sensitive polymer. The photoresist is exposed to light, which develops a pattern of exposed and unexposed areas on the silicon. The wafer is then developed to remove the exposed areas, leaving behind the circuits.
Refractory etching: Chemical etching can also be used to create refractory features on a chip. A refractory material is one that is not easily dissolved by the chemical solution. By using a resistor material on the front side of the chip and an etchant solution on the back side, the resistor is etched away, leaving the silicon area with a smooth, featureless surface.
Lithography: Chemical etching can also be used to remove materials from a glass substrate. The substrate is first cleaned and coated with a resistor film, which is a light-sensitive polymer. The resistor is exposed to light, which develops a pattern of exposed and unexposed areas on the substrate. The resistor is then developed to remove the exposed areas, leaving behind the pattern