Patent ID: 9054113
Filing Date: 2015-06-09
Classification: G03F,H01L

Abstract:
1. A box-in-box overlay mark, comprising an inner box region and an outer box region surrounding the inner box region; dense narrow trenches in a previous layer in the inner box region and the outer box region, wherein at least the dense narrow trenches in the inner box region are orientated in a direction different from an x- or y-direction; a plurality of x-directional and y-directional linear photoresist patterns defining a rectangle over the dense narrow trenches in the inner box region, wherein the linear photoresist patterns are defined in or from a photoresist layer for defining a current layer, and each of the linear photoresist pattern is wider than each of the dense narrow trenches; and a plurality of x-directional and y-directional linear patterns defining another rectangle in the outer box region, wherein the linear patterns are defined in or from the previously layer, and each of the linear patterns is wider than each of the dense narrow trenches.