Browsing by Author "Tasi, Min-Ching"

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Grating Pitch Measurement Beyond the Diffraction Limit with Modified Laser Diffractometry
(2011-06-01)
Pan, Shan-Peng
;
Liu, Tzong-Shi
;
Tasi, Min-Ching
;
Liou, Huay-Chung
;
機械工程學系
The demand for accurate measurements of nanostructures is increasing for the microprocesses and nanotechnology used in the semiconductor industry. In this study, we present an improved method for measuring gratings with a pitch size lower than one-half of the laser wavelength by using a modified laser diffractometer (LD). In experiments, the modified LD with a 633nm laser is used to measure a grating with a 288nm pitch size. This result is compared with results measured by both a metrological atomic force microscope and the traditional LD with a 543nm laser. The validity of this method is demonstrated. The difference between the pitch size of 288nm obtained by these three methods is approximately 0.17 nm. (C) 2011 The Japan Society of Applied Physics
Method for Determining the Angle in Two Dimension Nanoscale: Pitch Grating
(2011-06-01)
Pan, Shan-Peng
;
Liu, Tzong-Shi
;
Tasi, Min-Ching
;
Liou, Huay-Chung
;
機械工程學系
A two-dimensional (2D) grating is useful for calibrating the accuracy of an electron microscope and atomic force microscope (AFM). An inter laboratory comparison has been carried out for measuring pitches and angles of 2D gratings with 292 and 1000nm pitches using both AFM and an optical diffractometer (OD). The grating angle at the 292nm pitch size was obtained at some of the laboratories by the conventional OD method. However, they could not measure the grating angle when the grating pitch was smaller than (lambda/2) x root 2, where lambda denotes the laser wavelength. We propose a diffraction angle rotation method of grating angle measurements. Using a precision rotary table along with diffractive light, we accurately measure a 2D grating angle for any pitch size larger than lambda/2. (C) 2011 The Japan Society of Applied Physics