In order to meet stringent mask CD uniformity requirements, mask makers require a high precision CD metrology tool. According to the 2003 revision of the International Technology Roadmap for Semiconductors, there are no known solutions for sub-nanometer CD precision requirements. Furthermore, ITRS lists non-destructive, production worthy mask level microscopy for CD measurement for 3D structures as one of the five difficult challenges for 2009 and beyond. This paper focuses on the recent development successes of a scanning force based microscopy platform (Stylus NanoProfilometry, SNP). Innovative scanning strategies are discussed that enable high throughput, sub nanometer CD precision on advanced mask structures. Advancements in tip technology are also highlighted with metrology data presented on re-entrant alternating aperture phase shift mask features.