Dixson Ronald
Microsystems and Nanotechnology Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899.
J Micro Nanolithogr MEMS MOEMS. 2018 Oct;17(4). doi: 10.1117/1.jmm.17.4.044001.
One type of atomic force microscopy (AFM) used for critical dimension (CD) metrology is commonly referred to as critical dimension atomic force microscopy (CD-AFM); it uses flared tips and two-dimensional surface sensing to enable scanning of features with near-vertical sidewalls. An important consideration in this type of CD-AFM metrology is the calibration uncertainty of the tip width. Standards for traceable tip width calibration have thus been developed both by national metrology institutes (NMIs) and commercial suppliers. The National Institute of Standards and Technology (NIST) has previously reported the implementation of a self-consistency tip width calibration using three CD-AFM tips to image each other. The results of this method were shown to be consistent with prior calibrations based on transmission electron microscope cross-sections. In the present work, the extension of this method to tips smaller than 50 nm is demonstrated, as well as the extension of the method to include a second lateral axis.
一种用于关键尺寸（CD）计量的原子力显微镜（AFM）通常被称为关键尺寸原子力显微镜（CD-AFM）；它使用扩口尖端和二维表面传感来扫描具有近垂直侧壁的特征。这种类型的CD-AFM计量中的一个重要考虑因素是尖端宽度的校准不确定度。因此，国家计量机构（NMI）和商业供应商都制定了可溯源的尖端宽度校准标准。美国国家标准与技术研究院（NIST）此前曾报告过使用三个CD-AFM尖端相互成像来进行自洽尖端宽度校准的实施情况。该方法的结果与基于透射电子显微镜横截面的先前校准结果一致。在本工作中，展示了将该方法扩展到小于50 nm的尖端，以及将该方法扩展到包括第二个横向轴。
