Validation of Nu-Flare E-beam Emulation software in a Simulation Environment

In order to reduce mask making costs and improve wafer printability it is advantageous to determine machine parameters that will create highest probability of successful mask yield and mask image at CD and inspection. Proper simulation of actual product database helps to define the optimum e-beam machine settings for maximum probable yield and best mask pattern including OPC structures. In this paper we study the basic capability of the Nu-Flare E-beam mask writer emulation taking into account mask processing effects such as PEB. Analysis of how well software emulates the actual PEC corrections applied in the mask writer is necessary in predicting proper initial and subsequent machine settings for optimum yield and OPC structure fidelity. Comparisons of the Nu-Flare PEC emulation against actual mask PEC patterns on chrome masks are presented. Excellent agreement is found to experimental data when the PEC algorithm is modified to keep dose to the dense line pattern constant for any given setting of the eta PEC parameter.