Damage control during dry etching of EUV mask - 1 - Control of surface roughness

被引：4

作者：

Hoshino, E ^{[1
]}

Ogawa, T ^{[1
]}

Takahashi, M ^{[1
]}

Hoko, H ^{[1
]}

Yamanashi, H ^{[1
]}

Hirano, N ^{[1
]}

Okazaki, S ^{[1
]}

机构：

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

来源：

19TH ANNUAL SYMPOSIUM ON PHOTOMASK TECHNOLOGY, PTS 1 AND 2 | 1999年 / 3873卷

关键词：

EUV; tantalum; dry etching; mask; AFM;

D O I：

10.1117/12.373372

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

To obtain good optical properties in an EUVL mask, the substrate should not suffer any damage either during mask fabrication or during use. As one step in ensuring that this is the case, the surface roughness of patterns etched on a mask substrate was examined, since it reduces the reflectance of the substrate. The experiments involved coating a Mo/Si multilayer with a SiO2 buffer layer and a Ta absorber layer. After the absorber was dry etched with a mixture of Cl-2 and BCl3 gases, dry etching was used to over-etch the buffer layer. It was found that dry etching with Cl-2 + BCl3 provides both a smooth Ta surface (roughness: < 1 nm rms) and good control of the etching depth, even though the Ta etching rate was very high (389.6 nm/min.). The results indicate that the process used in this study is quite suitable for making absorber patterns.

引用

页码：786 / 791

页数：6

共 4 条

[1] Pattern etching of Ta X-ray mask absorber on SiC membrane by inductively coupled plasma [J].