Thin-film optimization strategy in high numerical aperture optical lithography, part 1: principles

Yu, Shinn-Sheng; Lin, Burn J.; Yen, Anthony; Ke, Chih-Ming; Huang, Jacky; Ho, Bang-Ching; Chen, Chun-Kuang; Gau, Tsai‐Sheng; Hsieh, Hong-Chang; Ku, Yao-Ching

doi:10.1117/1.2137967

Cited by 7 publications

(3 citation statements)

References 11 publications

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“…This is an example of a swing curve with minima and maxima. Wafer numbers 1,2,4, 6,8,10,12,14,16,18,20 and 22 are in first set while wafer 5,7,9,11,13,15,17,19,21,and 23 are in second set. Wafer number 24 is exposed and developed first to find out the center exposure so that the clearing points are in the middle of the 20 by 10 matrix.…”

Section: Methodsmentioning

confidence: 99%

“…The swing curve effect for an alternating phase shift mask was studied in [14].With the application of high numerical aperture exposure tools, the characteristic of swing curve with high numerical aperture was given in [15][16][17]. An analytical study of resist CD variation with respect to resist thickness was carried out in [18] and [19] using rigorous electromagnetic theory with stringent specification on CD, the demand for a uniform and repeatable resist thickness can be expected…”

Section: Introductionmentioning

confidence: 99%

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Statistical parameter evaluation for swing curves for the 1.2 μm and 1.8 μm resist thickness in CMOS photolithography process technology

Adam

Hashim

2012

2012 International Conference on Statistics in Science, Business and Engineering (ICSSBE)

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The swing curve is depending on the rotation speed of the spinner and the thickness of the photoresist. The thickness should be thick enough to prevent the unexposed area from being etched. It is also need to be uniform so that the image of the pattern to be developed later is in focus at all points on the resist surface. The variation of the photoresist thickness will impact the overall yield of the devices. In this respect, the photoresist thickness needs to be characterized carefully. Therefore, an experiment was set up to determine the right thickness and exposure time to control the critical dimension of the pattern. Photoresist coater and stepper are the main equipment used in this experiment. Positive photoresist is utilized as a pattern transfer medium and elipsometer is employed for film thickness measurement. 24 wafers are used in this experiment. The wafers are separated into 2 sets, each set which consists of 12 wafers have all the thickness variation. This to test the effect of standing resist before exposure and development to the dose-to-clear. The first set is coated, exposed and development. However, the second set is exposed and developed two days after being coated. After the wafer went through the standard cleaning procedure, the wafers were then coated using standard recipes which the spin speed ranging from 6500 to 7600 rpm in 100 rpm incremental with the designated rpm fro 1.2 µm photoresist thicknesses is in the middle. Subsequently, the photoresist thickness of each wafer is measured using elipsometer. Then, the exposure process is done by creating job that will expose the wafers in 20 by 10 arrays of small squares of open field with size 2x2 mm. The exposure is done in such a way where the exposure time will step up to the right and step down to the left from the center after each column. The center of the exposure energy time/step is 240/5. Then the graph is plotted to see the different. From the results we obtained that the minima for the dose-to-clear is at 7200 rpm where the thickness is 1.22 µm. whereby the first set and the second set of wafers produce a slight variation in clearing point.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Statistical parameter evaluation for swing curves for the 1.2 μm and 1.8 μm resist thickness in CMOS photolithography process technology

Adam

Hashim

2012

2012 International Conference on Statistics in Science, Business and Engineering (ICSSBE)

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“…A significant number of alternative methods by which to produce a desired field distribution exist such as apodisation or phase masks [5], polarisation structuring [6] and computer generated holograms [7,8]. Numerical optimisation is however normally used to determine the appropriate mask or field distribution to use [9]. To the best of the authors' knowledge there does not currently exist an analytic method to invert the Debye-Wolf integral in the literature.…”

Section: Introductionmentioning

confidence: 99%

Inversion of the Debye-Wolf diffraction integral using an eigenfunction representation of the electric fields in the focal region

et al. 2008

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Abstract:The forward problem of focusing light using a high numerical aperture lens can be described using the Debye-Wolf integral, however a solution to the inverse problem does not currently exist. In this work an inversion formula based on an eigenfunction representation is derived and presented which allows a field distribution in a plane in the focal region to be specified and the appropriate pupil plane distribution to be calculated. Various additional considerations constrain the inversion to ensure physicality and practicality of the results and these are also discussed. A number of inversion examples are given.

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Information in Polarisation Imaging

Foreman

2012

Springer Theses

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Thin-film optimization strategy in high numerical aperture optical lithography, part 1: principles

Cited by 7 publications

References 11 publications

Statistical parameter evaluation for swing curves for the 1.2 μm and 1.8 μm resist thickness in CMOS photolithography process technology

Statistical parameter evaluation for swing curves for the 1.2 μm and 1.8 μm resist thickness in CMOS photolithography process technology

Inversion of the Debye-Wolf diffraction integral using an eigenfunction representation of the electric fields in the focal region

Information in Polarisation Imaging

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Thin-film optimization strategy in high numerical aperture optical lithography, part 1: principles

Cited by 7 publications

References 11 publications

Statistical parameter evaluation for swing curves for the 1.2 &#x03BC;m and 1.8 &#x03BC;m resist thickness in CMOS photolithography process technology

Statistical parameter evaluation for swing curves for the 1.2 &#x03BC;m and 1.8 &#x03BC;m resist thickness in CMOS photolithography process technology

Inversion of the Debye-Wolf diffraction integral using an eigenfunction representation of the electric fields in the focal region

Information in Polarisation Imaging

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Statistical parameter evaluation for swing curves for the 1.2 μm and 1.8 μm resist thickness in CMOS photolithography process technology

Statistical parameter evaluation for swing curves for the 1.2 μm and 1.8 μm resist thickness in CMOS photolithography process technology