| Popis: |
The newest etching technique, magnetic neutral loop discharge etching (NLDE), is evaluated as a candidate for 130 nm device generation photomask fabrication. In order to ensure the mask etching performances corresponding to the 130nm generation, neutral loop discharge (NLD) etching feasibility for photomask fabrication was examined, and characteristics of NLD plasma and etching performances for Cr opaque material using a chemically amplified resist have been demonstrated. Under the practical etching conditions, nearly vertical Cr cross sectional profile with no undercutting for 0.4 micrometers mask patterns and sufficiently resist selectivity of 1.8 are obtained. CD linearity of down to 0.4 micrometers on the mask is ensured with remarkable CD accuracy. CD uniformity of 9.3 nm in range/2 on 88mm square area is achieved. CD variation caused by a global pattern density effect was examined and it was demonstrated that the NLD etching has higher performance for it in comparison with other etching systems. |
