| 摘要 |
An X-ray absorber used for X-ray lithography is made of Ta base metal and a small amount of additive element such as Al, Ti, Si or W. By adding such additive elements, the gas pressure in the sputtering chamber can be reduced compared to the pressure for sputtering pure Ta. The stress in the sputtered film is reduced, and the surface of the mask becomes smooth. By adding nitrogen to argon sputtering gas, the stress is further reduced. Sputtering is done using a composite target (5), which is made of Ta, and a plurality of studs (6) made of the additive element. The studs are embedded in holes formed on the surface of the target. By varying the number of the studs, the content of the added element can be varied. The reproducibility of such a sputtering method is very good and easy to control. Ar gas is used for sputtering. If nitrogen is mixed with the Ar, the stress in the sputtered film is further reduced. |
