Dynamics of nucleation in chemical vapor deposition

Technical Report · Wed Nov 01 04:00:00 EST 1995

DOI:https://doi.org/10.2172/170570· OSTI ID:170570

Mayer, T M; Adams, D P; Swartzentruber, B S; Chason, E

We study the evolution of layer morphology during the early stages of metal chemical vapor deposition (CVD) onto Si(100) via pyrolysis of Fe(CO){sub 5} below 250{degrees}C. Scanning tunneling microscopy (STM) shows that nuclei formation is limited by precursor dissociation which occurs on terraces, not at step sites. Also, the average size of clusters formed during CVD is larger than for Fe growth by evaporation (a random deposition process). Based on STM data and Monte Carlo simulations, we conclude that the CVD-growth morphology is affected by preferential dissociation of Fe(CO){sub 5} molecules at existing Fe clusters -- an autocatalytic effect. We demonstrate that nucleation kinetics can be used to control formation of metal nanostructures on chemically tailored surfaces. Reactive sites on Si (001) are first passivated by hydrogen. H atoms are locally removed by electron stimulated desorption using electrons emitted from the STM tip. Subsequent pyrolysis of Fe(CO){sub 5} leads to selective nucleation and growth of Fe films in the areas where H has been removed.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 170570
• Report Number(s): SAND--95-2471; ON: DE96003544
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBONYLS
CATALYSIS
CHEMICAL VAPOR DEPOSITION
IRON
IRON COMPOUNDS
NUCLEATION
PYROLYSIS
SILICON
SUBSTRATES
THIN FILMS