METHOD AND APPARATUS FOR THE ETCHING OF PHOTOMASK SUBSTRATES USING PULSED PLASMA

摘要

Disclosed is a method and apparatus for the etching of a thin film upon a photomask (24) . The etching is carried out in a reactor (20) via an inductively coupled pulsed plasma. Pulsing of the plasma is achieved by regulating the time period (or duty cycle) in which the plasma is generated. It has been found that by decreasing the duty cycle, high etch selectively can be achieved and feature sizes can be faithfully maintained.