Stay Justin L, Gaylord Thomas K
School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive. N.W., Atlanta, Georgia 30332-0250, USA.
Appl Opt. 2009 Aug 20;48(24):4801-13. doi: 10.1364/ao.48.004801.
Four distinct conditions for primitive-lattice-vector-direction equal contrasts in four-beam interference are introduced and described. By maximizing the absolute contrast subject to an equal contrast condition, lithographically useful interference patterns are found. Each condition is described in terms of the corresponding constraints on the plane wave wave vectors, polarizations, and intensities. The resulting locations of global intensity maxima, minima, and saddle points are presented. Subordinate conditions for unity absolute contrast are also developed. Three lattices are treated for each condition: simple cubic, face-centered cubic, and body-centered cubic.
介绍并描述了在四束干涉中原始晶格矢量方向等对比度的四个不同条件。通过在等对比度条件下最大化绝对对比度，找到了光刻中有用的干涉图案。每个条件都根据平面波波矢量、偏振和强度的相应约束进行了描述。给出了全局强度最大值、最小值和鞍点的最终位置。还推导了绝对对比度为1的从属条件。对每个条件处理了三种晶格：简单立方晶格、面心立方晶格和体心立方晶格。
