Weichelt T, Vogler U, Stuerzebecher L, Voelkel R, Zeitner U D
Opt Express. 2014 Jun 30;22(13):16310-21. doi: 10.1364/OE.22.016310.
The application of the phase-shift method allows a significant resolution enhancement for proximity lithography in mask aligners. Typically a resolution of 3 µm (half-pitch) at a proximity distance of 30 µm is achieved utilizing binary photomasks. By using an alternating aperture phase shift photomask (AAPSM), a resolution of 1.5 µm (half-pitch) for non-periodic lines and spaces pattern was demonstrated at 30 µm proximity gap. In a second attempt a diffractive photomask design for an elbow pattern having a half-pitch of 2 µm was developed with an iterative design algorithm. The photomask was fabricated by electron-beam lithography and consists of binary amplitude and phase levels.
相移法的应用能够显著提高掩膜对准器中接近式光刻的分辨率。通常，使用二元光掩模在30 µm的接近距离下可实现3 µm（半间距）的分辨率。通过使用交替孔径相移光掩模（AAPSM），在30 µm的接近间隙下，对于非周期性线条和间隔图案实现了1.5 µm（半间距）的分辨率。在第二次尝试中，使用迭代设计算法开发了一种用于半间距为2 µm的弯头图案的衍射光掩模设计。该光掩模通过电子束光刻制造，由二元振幅和相位级别组成。
