Rainbow 4420 Polysilicon

Polysilicon etchers are semiconductor process tools that remove patterned polysilicon from wafer surfaces. Polysilicon etchers are part of the dry etch equipment class used after lithographic patterning to transfer features into a deposited film. Single-wafer etchers process one wafer at a time under controlled plasma conditions.

Dry etch systems for polysilicon generally use reactive plasma chemistry to remove exposed film while preserving masked regions. Single-wafer cassette-to-cassette systems generally move wafers from carriers into a process chamber, carry out the etch step under controlled gas flow and temperature conditions, and then return the wafers to carriers. Electrostatic clamping is commonly used in this equipment class to hold wafers on the chuck during plasma processing. Gas delivery hardware and thermal control hardware are central subsystems in this equipment class because etch rate, profile control, and uniformity depend on chamber chemistry and wafer temperature.

Polysilicon etchers are used after a polysilicon film has been deposited and patterned with photoresist or another masking stack. Polysilicon etchers transfer the mask pattern into the polysilicon layer to define gates, conductors, or other device features. Subsequent flow commonly includes resist removal, post-etch cleaning, and follow-on dielectric, implant, or metallization steps depending on the device architecture.