Optical metrology tool, LX530, is designed for high throughput and dense sampling metrology in semiconductor manufacture. It can inspect the dose and focus variation in the process control based on the critical dimension (CD) and line edge roughness (LER) measurement. The working principle is shown with a finite-difference-time-domain (FDTD) CD simulation. Two optical post lithography wafers, including one focus-exposure-matrix (FEM) wafer and one nominal wafer, are inspected for CD, dose and focus analysis. It is demonstrated that dose and focus can be measured independently. A data output method based on global CD uniformity (CDU), inter CDU and intra CDU is proposed to avoid the data volume issue in dense sampling whole wafer inspection.
At SPIE 2013 in Metrology, Inspection, and Process Control for Microlithography an invited paper was published titled “In-line E-beam wafer metrology and defect inspection: the end of an era for image-based critical dimensional metrology? New life for defect inspection”. Three years have passed and numerous developments have occurred as predicted in this paper. The development of E-beam tools that can concurrently handle metrology and defect applications is one of the primary developments. In this paper, the capabilities of these new E-beam tools and their current use cases will be discussed in the areas of Critical Dimension Uniformity (CDU), In-die overlay, Hot spot and Physical defect inspection. Emphasis will be placed on use cases where “massive” CDU data is collected in order to increase yield learning for manufacturing (14nm) and decrease cycles of learning for development (7nm). Additionally, some of the other subject material from the previous publication will also be discussed such as the current state of E-beam critical dimension image fidelity and physical defect detection capabilities. Lastly, future directions and opportunities for In-line E-beam including Multi-beam and/or Multi-column E-beam will be discussed.
Proc. SPIE. 10145, Metrology, Inspection, and Process Control for Microlithography XXXI
KEYWORDS: Semiconductors, Signal to noise ratio, Metrology, Logic, X-rays, Silicon, Inspection, Image resolution, Scanning electron microscopy, Signal processing, 3D metrology, High volume manufacturing, Critical dimension metrology, Overlay metrology, Nanowires
This paper will provide a high level overview of the future for in-line high volume manufacturing (HVM) metrology for the semiconductor industry, concentrating on logic applications. First, we will take a broad view of the needs of patterned defect, critical dimensional (CD/3D), overlay and films metrology, and present the extensive list of applications for which metrology solutions are needed. Commonalities and differences among the various applications will be shown. We will then report on the gating technical limits of the most important of these metrology solutions to address the metrology challenges of future nodes, highlighting key metrology technology gaps requiring industry attention and investment