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The conventional premise, long-touted among the semiconductor processing community, that metrology is a "non-value-added necessary evil," is a misleading and dangerous assertion, which must be viewed as obsolete thinking. Many metrology applications are key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts of the processes.Various key trends in modern, state-of-the-art processing such as optical proximity correction, design for manufacturability, and advanced process control are based, at their hearts, on the assumption of fine-tuned metrology, in terms of uncertainty and accuracy. These trends are vehicles where metrology thus has large opportunities to create value through the engineering of tight and targetable process distributions. Such distributions make possible predictability in speed-sorts and in other parameters, which results in a high-end product. Additionally, significant reliance has also been placed on defect metrology to predict, improve, and reduce yield variability. The necessary quality metrology is strongly influenced by not only the choice of equipment, but also the quality application of these tools in a production environment. The ultimate value added by metrology is a result of quality tools run by a quality metrology team using quality practices. This paper will explore the relationships among present and future trends and challenges in metrology, including equipment, key applications, and metrology deployment in the manufacturing flow. Of key importance are metrology personnel, with their expertise, practices, and metrics in achieving and maintaining the required level of metrology performance, including where precision, matching, and accuracy fit into these considerations. The value of metrology will be demonstrated to have shifted to being a "key enabler of large revenues," debunking the out-of-date premise that metrology is "non-value-added." Index Terms-Advanced process control (APC), critical dimension (CD), design-based metrology (DBM), design for manufacturability (DFM), ISMI, metrology, optical proximity correction (OPC).

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The conventional premise that metrology is a is the result of the metrology team executing its job correctly "non-value-added necessary evil" is a misleading one, which and thoroughly. mufst he viewed as obsolete thinking. Much oJf the metrololQv requirements are now key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts ofthe processes. This paper will explore the present and future trends and challenges in CD metrology. However, equipment is only part of the battle. The quality application of these tools in a production environment is quite important; the ultimate valueadded by metrology is a result ofquality tools run by a quality metrology team using quality practices.

Accurate, precise, and rapid three-dimensional (3D) characterization of patterning processes in integrated circuit development and manufacturing is critical for successful volume production. As process tolerances and circuit geometries shrink with each technology node, the precision, accuracy, and capability requirements for dimension and profile metrology intensify. The present work adopts the scanning probe based technology, 3D atomic force microscopy (AFM), to address current and next-generation critical dimension (CD) metrology needs for device features at a variety of process steps. Fast, direct, and non-destructive 3D profile characterization of patterning processes is a primary benefit of CD AFM metrology. The CD AFM utilizes a deep trench (DT) mode for narrow and deep trenches, and a CD mode for linewidth and sidewall profiling. The 3D capability enables one tool for many applications where conventional scanning electron microscopy (SEM), scatterometry, and stylus profiler tools fall short: Gate etch/resist linewidth and sidewall cross-section profile, etch depth for high aspect ratio via, STI etch depth, 3D analysis for MUGFET multi-gate devices, pitch/CD/sidewall angle (SWA) verification for scatterometry targets, and post-CMP active recess. The AFM is an efficient tool for inline monitoring, rapid process improvement/development, and is a complementary addition to the dimension metrology family.