Abstract
Amorphous (Al 2 O 3 ) x -(TiO 2 ) 1-x composite films are prepared using r.f. unbalanced magnetron sputtering in an atmosphere of argon and oxygen at room temperature. The optical constants of (Al 2 O 3 ) x -(TiO 2 ) 1-x composite films are linearly dependent on the Al 2 O 3 mole fraction in the Al 2 O 3 -TiO 2 composite film. The optical constants of these Al 2 O 3 -TiO 2 composite films can be made to meet the optical requirements for a high transmittance attenuated phase shift mask (HT-APSM) blank by tuning the Al 2 O 3 mole fraction. The Al 2 O 3 mole fraction range that would allow the films to meet the optical requirements of an HT-APSM blank for ArF immersion lithography is calculated to be between 76% and 84%. One π-phase-shifted Al 2 O 3 -TiO 2 composite thin film to be used as an HT-APSM blank for ArF immersion lithography is fabricated and is shown to satisfy the optical requirements.
Original language | English |
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Pages (from-to) | 716-720 |
Number of pages | 5 |
Journal | Microelectronic Engineering |
Volume | 84 |
Issue number | 5-8 |
DOIs | |
State | Published - 1 May 2007 |
Keywords
- ArF immersion lithography
- Composite film
- High transmittance attenuated phase shift mask
- Optical property