Development of EUV mask inspection system using high-order harmonic generation with a femtosecond laser

作者：Kinoshita Hiroo^*; Harada Tetsuo; Nagata Yutaka; Watanabe Takeo; Midorikawa Katsumi

来源：Japanese Journal of Applied Physics, 2014, 53(8): 086701.

DOI：10.7567/JJAP.53.086701

An EUV mask inspection system, called a coherent scatterometry microscope (CSM), has been developed, in which high-order harmonic generation (HHG) is employed to produce coherent 13.5 nm light. It was designed for detecting defects and measuring the critical dimension (CD) of EUV mask patterns. The required resolution for pattern defects is 20 nm, and the required repeatability for CD measurements is 0.1 nm. To achieve these specifications, it was necessary to return to the basic principles of optics and to develop a new inspection method, rather than relying on conventional optics, such as those of an optical microscope. The HHG-CSM was used to inspect absorber pattern defects (missing holes, bridges) for the 22 nm node by the die-to-die method and was found to exhibit satisfactory performance.

• 出版日期2014-8
• 单位RIKEN