| 摘要 |
PROBLEM TO BE SOLVED: To provide a halftone phase shift type photomask blank having a halftone phase shift film that has excellent chemical resistance, contains Si and one element selected from nitrogen and oxygen or both, and has good in-plane uniformity of optical characteristics.SOLUTION: Provided that a hysteresis curve defining a hysteresis region is drawn by applying a constant power across a target, sweeping the flow rate of a reactive gas introduced into a chamber, measuring a target voltage or target current value upon sweeping of the reactive gas flow rate, and plotting the target voltage or target current value versus the reactive gas flow rate, a halftone phase shift mask is formed by reactive sputtering while a reactive gas flow rate A is set to equal to or lower than the lower limit of the reactive gas flow rate in the hysteresis region, and a reactive gas flow rate C is set inside the lower and upper limits of the reactive gas flow rate in the hysteresis region.SELECTED DRAWING: Figure 1 |
