Fine pattern definition with atomic intermixing induced by focused ion beam and its application to x-ray mask fabrication

Conference · · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States)

OSTI ID:6104045

Kanayama, Toshihiko; Komuro, Masanori; Hiroshima, Hiroshi; Itoh, Junji; Atoda, Nobufumi; Tanoue, Hisao; Tsurushima, Toshio ^[1]

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1. Electrotechnical Lab., Ibaraki (Japan)

Mixing of double-layered Al-on-Au and Al-on-W structures by a focused ion beam (FIB) has been used to define fine patterns in Au and W layers and to demonstrate that the mixing spread is less than 0.1 {mu}m. Since the mixed Al-Au alloy and Au have higher sputtering yield than Al, etching with 4-keV Xe ions engraves the FIB-defined pattern in the Au layer. This process yielded 0.2-{mu}m-wide grooves in 20-nm Al/0.3{mu}m Au with a 50-keV Ga{sup +} FIB of {approximately} 5 {times} 10{sup 15}/cm{sup 2}. In the Al/W, Al is removed in H{sub 3}PO{sub 4} leaving the mixed Al-W alloy, which acts as a durable mask in SF{sub 6} reactive ion etching of W with a selectivity of {approximately} 80 . This process enables the Ga{sup +} FIB to define patterns less than 0.1 {mu}m in 20-nm Al/0.3-0.5-{mu}m W with a sensitivity of {approximately} 1 {times} 10{sup 15}/cm{sup 2}. To demonstrate applicability of the above processes, patterns of x-ray masks were fabricated and transferred with synchrotron radiation to poly-methyl-methacrylate (PMMA). Backscattering measurements of He ions and x-ray diffraction verify mixing occurs within the range of the ion. The process performance and its relation with the mixing kinetics are also discussed.

• OSTI ID: 6104045
• Report Number(s): CONF-9009402-; CODEN: JVTBD
• Journal Information: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States), Vol. 9:2; Conference: Workshop on high-density plasma techniques and processes for integrated circuit fabrication, Burlingame, CA (United States), 11-12 Sep 1990; ISSN 0734-211X
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
36 MATERIALS SCIENCE
GOLD
ELECTRON BEAM MACHINING
PROTECTIVE COATINGS
FABRICATION
TUNGSTEN
ALUMINIUM ALLOYS
DEPOSITION
ETCHING
FOCUSING
ION BEAMS
LAYERS
MASKING
SPUTTERING
SUBSTRATES
ALLOYS
BEAMS
COATINGS
ELEMENTS
MACHINING
METALS
SURFACE FINISHING
TRANSITION ELEMENTS
426000* - Engineering- Components
Electron Devices & Circuits- (1990-)
360601 - Other Materials- Preparation & Manufacture
360602 - Other Materials- Structure & Phase Studies