20 August 1986 Simulations Of Optical Lithography Test Structures: Murray Daggers And Contact Arrays
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This paper presents simulations of lithography test structures, Murray daggers and contact arrays, and includes comparisons to experiment. Murray daggers are triangular structures whose height is determined by lithography system resolution and process conditions. The tip of a dagger can be seen optically (with a 50 or 100X magnification), making it simple to use. Contact arrays are measured by locating the smallest size contact where the resist has cleared. Aerial image and development simulation programs (SAMPLE) are used to find clearpoint regions in the structure for given lithographic conditions. The location of the clearpoint within the structure is then mapped out as a function of stepper exposure dose and defocus value. Correlations of dagger and contact array readings to develop check CD's are also derived. From the structures investigated, it is found that contact arrays with varying dimensions are sensitive to defocus at low doses (1.2 times the dose needed to clear a large area in the resist, 1.2E0), and that line daggers are the most sensitive at high doses (3.6E0). Sensitivity to exposure dose depends on defocus for all the test structures, but the space dagger appears to be the most reliable indicator. Correlations of printed spacewidth to test structure readings reveal sensitivities on the order of .1 micron/ 1 increment change observed in readings. Experimental dagger measurements suggeit that the simulations are correct.
© (1986) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Andrew Muray, Andrew Muray, Doug Thompson, Doug Thompson, } "Simulations Of Optical Lithography Test Structures: Murray Daggers And Contact Arrays", Proc. SPIE 0633, Optical Microlithography V, (20 August 1986); doi: 10.1117/12.963729; https://doi.org/10.1117/12.963729

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