采用双向偏置曝光的成像干涉光刻技术

成像干涉光刻技术(IIL)具有干涉光刻技术(IL)的高分辨力和光学光刻技术(OL)产生任意形状集成电路特征图形的能力。在IIL中,按掩模图形的不同空间频率成份分区曝光,并使其在抗蚀剂基片上非相干叠加,得到高分辨抗蚀剂图形。本文在研究一般三次曝光IIL原理基础上,提出采用沿X轴正、负方向以及沿Y轴正、负方向偏置的双向偏置照明,分别曝光 X方向、-X方向、 Y方向、-Y方向的高空间频率分量并与垂直于掩模方向的低空间频率分量曝光相结合的五次曝光IIL。理论和计算模拟表明,该方法可以提高图形对比度和分辨力,并减小因调焦误差引起的图形横向位移误差,有利于改善抗蚀剂图形质量。

Imaging interferometric lithography with bidirection biased illumination

Imaging Interferometric Lithography (IIL) has high resolution of interferometric lithography(IL) and ability for printing arbitrary patterns of optical lithography (OL). By exposing different spatialfrequency sections respectively and making the exposures noncoherently superposed on photoresistcoated substrate, better resist patterns with higher resolution and arbitrary IC patterns can be obtained. Inthe paper, based on conventional tri-exposure IIL, proposed is a new IIL which uses five exposures,including four biased exposures for higher spatial frequency components of patterns on mask in X, -X, Y and -Y directions along X and Y axes, respectively, and a perpendicularly illuminated exposurerelative to mask plane with lower spatial frequency. Theoretical research and computer simulation showthat the new IIL can obtain higher resolution and better resist patterns as well as decrease position errorof patterns out of focusing.