Process scheme for removing buffer layer on multilayer of EUVL mask

被引：5

作者：

Hoshino, E ^{[1
]}

Ogawa, T ^{[1
]}

Takahashi, M ^{[1
]}

Hoko, H ^{[1
]}

Yamanashi, H ^{[1
]}

机构：

[1] NTT, Telecommun Energy Labs, Atsugi Res Ctr, Assoc Super Adv Elect Technol, Atsugi, Kanagawa 2430198, Japan

来源：

PHOTOMASK AND NEXT-GENERATION LITHOGRAPHY MASK TECHNOLOGY VII | 2000年 / 4066卷

关键词：

EUVL; buffer layer; mask; side etching; SiO2;

D O I：

10.1117/12.392050

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

In the fabrication of masks for Extreme Ultraviolet Lithography (EUVL), a combination of dry and wet etching was used to remove the SiO2 buffer layer. This technique greatly improves the pattern quality, yielding re-entrant shaped mask patterns with a steep SiO2 sidewall. Under proper conditions, etching results in the base of the sidewall being recessed around 5 nm from the edge of the Ta pattern. The strength of hydrofluoric acid (HF) solution was set to 3.3% to allow good control of the etching rate. A combination of dry and wet etching is an effective way to remove the SiO2 buffer layer because it can compensate for a variation of as much as 7.6% in the thickness of the SiO2 film before etching.

引用

页码：124 / 130

页数：7