Editing Dry etching (section)

==Hardware design==
The dry etching hardware design basically involves a [[vacuum chamber]], special gas delivery system, [[radio frequency]] (RF) [[waveform generator]] to supply power to the plasma, heated chuck to seat the wafer, and an exhaust system.

Design varies from manufacturers such as Tokyo Electronic, Applied Materials, and Lam. While all designs follow the same physical principles, the variety of designs target more specialized processing characteristics. For example, dry etch steps that come into contact with or form critical parts of the device may require higher levels of directionality, selectivity, and uniformity. The tradeoff is that more complex dry etch equipment comes at a higher cost to purchase and is more difficult to understand, more expensive to maintain, and may operate more slowly. 

Dry etch equipment can control for process uniformity with several knobs. The chuck temperature can be varied to control the heat of the wafer across the radius of the wafer, which influences the rate of reactions and thus the etch rate across different regions of the wafer. The plasma uniformity can be controlled with plasma confinement, which may be controlled with a high speed magnet rotating around the chamber, variations in gas flow into the chamber and pump out of the chamber, or RF braiding around the chamber. These strategies vary per equipment manufacturer and intended application.