Nanometer scattered-light alignment system using SiC x-ray masks with low optical transparency

Miyatake, Tsutomu; Hirose, Masaoki; Shoki, Tsutomu; Okubo, Ryo; Yamazaki, Keisuke

doi:10.1116/1.590479

Cited by 11 publications

(2 citation statements)

References 5 publications

(3 reference statements)

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“…Fig.2(b) shows 10-µm wide loops and lines on the first mask for the aligned exposure. For aligned x-ray exposures, a number of materials, such as boron-doped silicon 23,24 , silicon nitride 11,23 , silicon carbide [23][24][25][26] , diamond [23][24][25]27 , and polyimide [15][16][17][18][19][20][21] , have been utilized as membranes. While stiff materials offer better mechanical support and thus less mask distortion, their membranes must be thin enough (typically less than 1 µm) to transmit sufficient visible light.…”

Section: Polyimide X-ray Maskmentioning

confidence: 99%

High-aspect-ratio microstructures for magnetoelectronic applications

et al. 2003

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This paper describes a process to fabricate three-dimensional multilevel high-aspect-ratio microstructures (HARMs) for magnetoelectronic devices using aligned x-ray lithography in conjunction with electrodeposition. In this process, x-ray masks were constructed on a seed layer coated polyimide membrane with ultraviolet (UV) patterned and electrodeposited gold absorbers. The optically transparent polyimide allows one to align and print large areas (>4 inch in diameter) with high alignment accuracies. Patterns that contain 5-10 µm diameter posts and 7-10 µm wide lines were printed to 100-120 µm polymethyl methacrylate (PMMA) resist prepared on silicon wafers using x-ray lithography. Nickel-iron was electroplated to form ferromagnetic HARMs, while electroplated gold formed circuits. The composition profile measured with an electron probe x-ray microanalyzer (EPMA) suggested that iron content increases as NiFe plating proceeds inside the recess. The electrodeposition resulted in well-defined NiFe structures with aspect-ratios up to 20:1, smooth sidewalls and top surfaces. To isolate the magnetic structures and circuits, both wet chemical etching and sputter etching were explored to remove seed layer, and the latter yielded complete removal without noticeable damage to the features. A complete aligned x-ray exposure and electrodeposition protocol applicable to universal multilevel microstructures was established.

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Section: Polyimide X-ray Maskmentioning

confidence: 99%

High-aspect-ratio microstructures for magnetoelectronic applications

et al. 2003

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“…Traditionally, the positioning techniques can be mainly classified into three categories: the geometric imaging scheme that direct compares two cross or bar like geometric marks located on wafer and mask using a screen or CCD [1][2][3] , the zone plate scheme that detects the critical value of the intensity of one beam or the relative intensity of two beams generated using the linear zone plate based marks on wafer and mask [4,5] , the homodyne method that measures the intensity of two interfered beams diffracted from two grating marks on wafer and mask [6], the heterodyne method measures the phase difference of two beat signal generated by interference of two beams with close frequencies diffracted from wafer and mask respectively [ 7 ]. Somehow, most of these intensity or phase based techniques are more applied in X-ray lithography and lack flexibility.…”

Section: Introductionmentioning

confidence: 99%

Positioning scheme based on grating modulation and phase imaging in lithography

Zhou

et al. 2010

5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Design, Manufacturing, and Testing of M

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As the critical techniques of lithographic system, the nano-positioning techniques, including the wafer-mask alignment, gapping between wafer and mask and wafer focusing, are of great significance to the improvement of resolution of the projection lithography and the proximity nanolithography, such as X-ray lithography, nanoimprint, and zone-plate-array lithography etc. This paper presents a scheme based on grating modulation and spatial phase imaging. The relative move and gap variation between mask and wafer can be associated with the shift or phase variation of fringe pattern and obtained simultaneously. Two gratings with slightly different periods are adopted as alignment marks and gapping marks on wafer and mask. Fringes with period that is inversely proportional to the difference of periods of two gratings occur in the superposition of two grating marks. First, the theoretical background is introduced and the mechanism of alignment gapping is detailed. Next, the scheme and framework of alignment and gapping method is constructed. Finally, numeric computational and experimental results indicate that the displacement detectivity at nanometer or even sub-nanometer level can be realized in this scheme

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Single closed fringe pattern phase demodulation in alignment of nanolithography

Yang

et al. 2013

Optik

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Nanometer scattered-light alignment system using SiC x-ray masks with low optical transparency

Cited by 11 publications

References 5 publications

High-aspect-ratio microstructures for magnetoelectronic applications

High-aspect-ratio microstructures for magnetoelectronic applications

Positioning scheme based on grating modulation and phase imaging in lithography

Single closed fringe pattern phase demodulation in alignment of nanolithography

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