Topography hotspot-aware process control metrology cell insertion: DFM: Design for manufacturability

Abstract

A novel Process Control Metrology (PCM) cell placement methodology to improve Depth of Focus (DOF) control in the advanced VLSI design is presented. PCM cells are typically inserted in both FEOL and BEOL chip design layers in order to control mask image size, improve mask alignment, monitor Critical Dimension (CD), and analyze critical process parameters. As process technology scales down, CMP related hotspots, such as Cu pooling and Depth of Focus (DOF) hotspots at high or low topography areas become prominent[1] and need to be detected, analyzed and accommodated for better yield [2][3]. In the new methodology, an intelligent analysis of design drives optimal placement of conventional PCM cells to achieve better DOF control and CMP monitoring.