Surface chemistry of fluorine-containing molecules related to CVD process on silicon nitride: SiF{sub 4}, XeF{sub 2}, and HF

Conference · Tue Dec 31 04:00:00 EST 1991

OSTI ID:10121856

Outka, D A

The reactivity of several fluorine-containing molecules on a polycrystalline silicon nitride (Si{sub 3}N{sub 4}) surface is studied under ultrahigh vacuum (UHV) conditions using temperature programmed disorption (TPD) and Auger electron spectroscopy (AES). The chemistry of fluorine of Si{sub 3}N{sub 4} is of interest in understanding the high temperature chemical vapor deposition (CVD) of Si{sub 3}N{sub 4}, which uses SiF{sub 4} as a starting material. XeF{sub 2} is reacted with a Si{sub 3}N{sub 4} surface to prepare and characterize various surface SiF{sub x} (1 {le} {times} {le} 3) species. These are identified by the chemical shift induced by the fluorine atoms in the Si (LMM) Auger peak and by changes in the TPD. Of these species, SiF{sub 2} is stable to the highest temperature. SiF{sub 2} is also formed by the reaction of SiF{sub 4} with a Si{sub 3}N{sub 4}. Because SiF{sub 2} is so stable, its decomposition is proposed as a rate-determining step in the CVD deposition of Si{sub 3}N{sub 4} from SiF{sub 4}. Gaseous HF, which is a product of the CVD process, does not dissociate on Si{sub 3}N{sub 4} and is therefore unlikely to cause the etch-like marks on the Si{sub 3}N{sub 4} coating that are observed under certain conditions. 8 refs., 6 figs.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DR00789
• OSTI ID: 10121856
• Report Number(s): SAND--91-8728; CONF-911202--56; ON: DE92007508
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202
360204
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201
AUGER ELECTRON SPECTROSCOPY
CHEMICAL AND PHYSICOCHEMICAL PROPERTIES
CHEMICAL REACTIONS
CHEMICAL VAPOR DEPOSITION
DESORPTION
HYDROFLUORIC ACID
PHYSICAL PROPERTIES
SILICON FLUORIDES
SILICON NITRIDES
STRUCTURE AND PHASE STUDIES
TEMPERATURE DEPENDENCE
XENON FLUORIDES