Nanometer-scale lithography on Si(001) using adsorbed H as an atomic layer resist

Journal Article · Wed May 01 04:00:00 EDT 1996 · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena

DOI:https://doi.org/10.1116/1.589204· OSTI ID:285557

Adams, D P; Mayer, T M; Swartzentruber, B S ^[1]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185-1413 (United States)

We describe nanometer-scale feature definition in adsorbed hydrogen layers on Si(001) surfaces by exposure to low energy electrons from a scanning tunneling microscope tip. Feature sizes range from {lt}5 to {approx_gt}40 nm as a function of bias voltage (5{endash}30 V) and exposure dose (1{endash}10{sup 4} {mu}C/cm). We show that the cross section for electron stimulated desorption of hydrogen has a threshold at 6{endash}8 eV and is nearly constant from 10 to 30 eV, so that above threshold the feature profiles are a direct reflection of the electron flux profile at the surface. Radial flux distributions are best fit by a simple exponential function, where the decay length is dependent primarily on the tip{endash}sample separation. Low intensity tails at large radius are also observed for high bias emission. Comparison to field emission simulations shows that our tip has an {open_quote}{open_quote}effective radius{close_quote}{close_quote} of approximately 30 nm. Simulations demonstrate that tip geometry and tip{endash}sample separation play the dominant role in defining the electron flux distribution, and that optimum beam diameter at the sample is obtained at small tip{endash}sample separation (low bias) with sharp tips. We show that adsorbed hydrogen is a robust resist that can be used as a mask for selective area deposition of metals by chemical vapor deposition. Fe lines 10 nm wide are deposited by pyrolysis of Fe(CO){sub 5} in areas where H has been desorbed, with minimal nucleation in the H-passivated areas. {copyright} {ital 1996 American Vacuum Society}

• Research Organization: Sandia National Laboratory
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 285557
• Journal Information: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena, Journal Name: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena Journal Issue: 3 Vol. 14; ISSN JVTBD9; ISSN 0734-211X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADSORPTION
CHEMICAL VAPOR DEPOSITION
FIELD EMISSION
HYDROGEN
LITHOGRAPHY
SILICON
SURFACE TREATMENTS