Study of SiO{sub x}N{sub y} as a bottom antireflective coating and its pattern transferring capability
- RHO, Seagate Technology, 7801 Computer Ave. South, Bloomington, Minnesota 55438 (United States)
To meet such challenges for the controlling of critical feature dimension at sub-50-100-nm, it has been a general industrial trend to employ shorter wavelength (193 nm, for example) lithography for better resolution and to use bottom antireflective coating (BARC) for a reduced standing wave formation and thus, a better critical dimensional control. Matching the optical constants (n,k) between the BARC, photoresist, and the underlayer to be patterned is critical for the elimination of such standing waves. SiO{sub x}N{sub y} and SiO{sub x}C{sub y} are two attractive inorganic BARC candidates in view of their easily adjustable optical constants by varying the deposition parameters and their etching compatibility with standard semiconductor plasma processes. In this article, SiO{sub x}N{sub y} films were prepared by plasma enhanced chemical vapor deposition approach. These films have been further characterized using x-ray photoelectron spectroscopy for chemical composition depth profile, Fourier transform infrared spectroscopy for local chemical bonding, and ellipsometry for optical constants. It has been demonstrated that the refractive indices of SiO{sub x}N{sub y} can be tuned from 1.6 to 2, while the absorption constants k can be adjusted from 0.1 to 0.9 by changing the process parameters, such as SiH{sub 4} flow rate, NH{sub 3} flow rate, and SiH{sub 4}/N{sub 2}O ratio. To integrate the SiO{sub x}N{sub y} BARC film into the storage device manufacturing, the pattern transferring capability of SiO{sub x}N{sub y} has been discussed. A film stack structure of photoresist/SiO{sub x}N{sub y}/carbon or SiC hard mask/magnetic device layer has been used to evaluate the performance of the SiO{sub x}N{sub y} BARC. SiO{sub x}N{sub y} film was opened via inductively coupled plasma etching with CHF{sub 3}+O{sub 2} chemistry, while carbon and SiC hard masks were opened using He-O{sub 2} and SF{sub 6}-He-O{sub 2} chemistries, respectively. SiF emission line at 388 nm wavelength was used for end point during the SiO{sub x}N{sub y} etching, while the 778 nm O peak and 685 nm F peak have been used for carbon and SiC end pointing. The profiles of the etched SiO{sub x}N{sub y} and carbon/SiC were analyzed by cross-section transmission electron microscopy.
- OSTI ID:
- 20979464
- Journal Information:
- Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 25, Issue 4; Other Information: DOI: 10.1116/1.2742389; (c) 2007 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AMMONIA
ANTIREFLECTION COATINGS
CARBON
CHEMICAL BONDS
CHEMICAL VAPOR DEPOSITION
ETCHING
FILMS
FLUOROFORM
FOURIER TRANSFORM SPECTROMETERS
INFRARED SPECTRA
NITROUS OXIDE
PLASMA
REFRACTIVE INDEX
SILANES
SILICON CARBIDES
SULFUR FLUORIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY PHOTOELECTRON SPECTROSCOPY