Aberration measurement of projection optics in lithographic tools by use of an alternating phase-shifting mask


Autoria(s): Wang F; Wang XZ; 马明英; Zhang DQ; Shi WJ; Hu JM
Data(s)

2006

Resumo

As a critical dimension shrinks, the degradation in image quality caused by wavefront aberrations of projection optics in lithographic tools becomes a serious problem. It is necessary to establish a technique for a fast and accurate in situ aberration measurement. We introduce what we believe to be a novel technique for characterizing the aberrations of projection optics by using an alternating phase-shifting mask. The even aberrations, such as spherical aberration and astigmatism, and the odd aberrations, such as coma, are extracted from focus shifts and image displacements of the phase-shifted pattern, respectively. The focus shifts and the image displacements are measured by a transmission image sensor. The simulation results show that, compared with the accuracy of the previous straightforward measurement technique, the accuracy of the coma measurement increases by more than 30% and the accuracy of the spherical-aberration measurement increases by approximately 20%. (c) 2006 Optical Society of America.

Identificador

http://ir.siom.ac.cn/handle/181231/1794

http://www.irgrid.ac.cn/handle/1471x/10422

Idioma(s)

英语

Fonte

Wang F;Wang XZ;马明英;Zhang DQ;Shi WJ;Hu JM.,Appl. Optics,2006,45(2):281-287

Tipo

期刊论文