Immersion liquids for lithography in the deep ultraviolet

被引：26

作者：

Switkes, M ^{[1
]}

Kunz, RR ^{[1
]}

Sinta, RF ^{[1
]}

Rothschild, M ^{[1
]}

Gallagher-Wetmore, PM ^{[1
]}

Krukonis, VJ ^{[1
]}

Williams, K ^{[1
]}

机构：

[1] MIT, Lincoln Lab, Lexington, MA 02420 USA

来源：

OPTICAL MICROLITHOGRAPHY XVI, PTS 1-3 | 2003年 / 5040卷

关键词：

D O I：

10.1117/12.485329

中图分类号：

O43 [光学];

学科分类号：

070207 [光学]; 0803 [光学工程];

摘要：

The requirements of liquids for use in immersion lithography are discussed. We present simple calculations of the transmission and index homogeneity requirements of the immersion liquid (T > 0.95 and deltan < 5 x 10(-7) respectively for sin 0 = NA/n = 0.9 and a working distance of 1 mm) along with the temperature and pressure control requirements which follow from them. Water is the leading candidate immersion liquid for use at 193 rim, and we present data on its chemical compatibility with existing 193 rim resists through dissolution/swelling and surface energy studies. We find that it has a minimal impact on at least some current 193 nm resists. At 157 nm, suitably transparent immersion fluids remain to be identified. Perfluorinated polyethers (PFPE) are among the most transparent organics measured. The lowest PFPE absorbance at 157 nm can be further reduced by roughly a factor of two, from 6 to 3 cm(-1) through removal of dissolved oxygen. We also discuss our efforts to understand the origin of the remaining absorbance through supercritical CO2 fractionation.

引用

页码：690 / 699

页数：10

共 20 条

[1]

*AUS INC, 2002, FOMBL PFPE FLUIDS GA

[2]

Benschop J., 2001, Microlithography World, V10, P4

[3]

SURVIVAL OF MAMMALS BREATHING ORGANIC LIQUIDS EQUILIBRATED WITH OXYGEN AT ATMOSPHERIC PRESSURE [J].