Pellicle Division

Definition and Usage

A Pellicle is a thin, transparent membrane that seals off the mask or reticle surface from airborne particulates and other forms of contamination. The membrane is mounted on a metal (usually anodized Aluminum) frame that is securely fastened onto the reticle. Generally, the pellicle is attached only onto chrome side of the reticle for projection aligner. For steppers, the pellicles are usually bonded onto both the chrome and the glass sides of the reticle. Particles residing on the pellicle surface are located at a sufficient distance from the reticle surface so as to have a negligible effect on the wafer image.

Pellicle Protection Machanism

Pellicle Structure

Purpose of Pellicle Use

• Improvement in acquiring rate of semiconductor products
• Protection from photo-mask pollutions
• Extension of life expectancy of photo-mask
• Extension of cleaning period of photo-mask
• Segregation from the pollution sources for repetitive photo-mask usages