D2S (R), a supplier of GPU-enabled software for semiconductor manufacturing, today announced that it has partnered with Advantest, the world’s largest supplier of semiconductor Automatic Test Equipment, to integrate D2S’ Wafer Plane Analysis engine into Advantest’s Mask MVM-SEM (Multi Vision Metrology Scanning Electron Microscope) systems. This new capability enables fast and highly repeatable CD metrology for complex photomask shapes, including those created by inverse lithography technology (ILT), which enables photomask manufacturers to quickly, accurately and cost-effectively identify mask-level CD uniformity (CDU) issues that will impact the wafer during subsequent lithography processing in the wafer fab.
“We’re pleased to be working with D2S on developing a joint solution to improve mask CDU analysis, which results in a better quality mask for our customers,” stated Takayuki Nakamura, Executive Officer, General Manager of Nanotechnology Business Division, Advantest. “Combining D2S’ expertise in GPU-accelerated simulation technologies with our leading-edge CD-SEM tools-such as our new E3640-allows us to provide a cost-effective platform for extremely fast lithography simulation.”
Advanced photomasks are increasingly adopting non-orthogonal patterns and complex shapes, such as curvilinear mask patterns, due to the need for aggressive optical proximity correction (OPC) and ILT to enable production of leading-edge semiconductor devices with ever-smaller feature sizes. As these mask patterns become more complex, conventional CD metrology that measures CDs on straight lines/spaces no longer works since most mask patterns do not have uniform CDs after OPC and ILT correction. In addition, the number of mask defect issues flagged during mask inspection increases. However, not all of these mask issues will actually result in yield problems on the wafer. As a result, this increases the need for photomask manufacturers to understand the wafer-level impact of mask-level issues.
Wafer plane (aerial) analysis has emerged as a solution for identifying mask-level CDU issues that will impact the wafer. However, optical-based wafer plane analysis solutions are expensive, can be slow to implement, and have difficulty providing repeatable results. Mask manufacturers need a new wafer plane analysis solution that is less expensive, faster, and highly repeatable without requiring new equipment or additions to the mask inspection process.
The D2S Wafer Plane Analysis Engine provides aerial simulation of mask contours extracted by the Advantest MVM-SEM for today’s complex mask patterns, including ILT shapes for memory and logic. It is fully integrated into the Advantest CD-SEM system, which enables mask shops to access the benefits of GPU-accelerated wafer plane analysis without adding costly iterations with a standalone optical system.
“GPU acceleration is a powerful tool for enabling fast and accurate aerial simulation of complex mask patterns. It is particularly advantageous on curvilinear mask contours, which are increasingly being populated in today’s leading-edge photomasks,” stated Dr. Linyong (Leo) Pang, chief product officer and executive vice president of D2S. “The new Wafer Plane Analysis Engine from D2S provides wafer plane analysis capability within seconds. Combining our capability with Advantest’s SEM solutions gives their customers a powerful solution for identifying which mask features truly have a CDU problem on the wafer in order to enable swift and cost-effective correction. It can also be used for mask post-inspection defect review to enable fast dispositioning of defects based on their simulated printability. “