X-ray photoemission spectroscopy characterization of silicon surfaces after CF/sub 4//H/sub 2/ magnetron ion etching: Comparisons to reactive ion etching

Journal Article · Sun May 01 00:00:00 EDT 1988 · J. Vac. Sci. Technol., A; (United States)

DOI:https://doi.org/10.1116/1.575222· OSTI ID:5155432

Oehrlein, G S; Bright, A A; Robey, S W

Silicon surfaces subjected to CF/sub 4/H/sub 2/ magnetron ion etching (MIE) have been characterized by x-ray photoemission spectroscopy. Low-power-density (0.274 Wcm/sup 2/) 25-mTorr MIE plasmas cause fluorocarbon films on Si which are characterized by C--CF/sub x/, CF, CF/sub 2/, and CF/sub 3/ groups. Graphitic carbon and silicon carbon type bonding can also be observed at the filmsilicon interface. Thicker films are formed in hydrogen-rich CF/sub 4/H/sub 2/ etching gas mixtures. Carbonaceous films with significant chemical differences are produced under high-powerlow-pressure MIE operating conditions (1 Wcm/sup 2/ at 4 mTorr). These films are characterized primarily by C--CC--H type carbon and a very low intensity of highly fluorinated carbon groups. The carbonfluorine ratio is 0.8 for the films formed in a pure CF/sub 4/ magnetron discharge at a power density of 0.27 Wcm/sup 2/, similar to that of films formed in a conventional reactive ion etch plasma, whereas it is 2.2 for the films formed at a power density of 1 Wcm/sup 2/. The carbonaceous film formed during high-power MIE does not have a dominant role in determining the silicon etching behavior in contrast to fluorocarbon films formed under low-power MIE conditions which suppress the Si etch rate. This explains the lack of SiO/sub 2/Si etch selectivity observed under high-power MIE conditions using CF/sub 4/H/sub 2/ in contrast to low-power magnetron ion etching where SiO/sub 2/Si etch selectivity is achieved.

• Research Organization: IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 5155432
• Journal Information: J. Vac. Sci. Technol., A; (United States), Vol. 6:3
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARBON FLUORIDES
COLLISIONS
HYDROGEN
SILICON
ETCHING
ION COLLISIONS
PHOTOELECTRON SPECTROSCOPY
COMPARATIVE EVALUATIONS
FILMS
PHOTOEMISSION
SILICA
SURFACES
X RADIATION
CARBON COMPOUNDS
CHALCOGENIDES
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
EMISSION
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
IONIZING RADIATIONS
MINERALS
NONMETALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
SECONDARY EMISSION
SEMIMETALS
SILICON COMPOUNDS
SILICON OXIDES
SPECTROSCOPY
SURFACE FINISHING
656003* - Condensed Matter Physics- Interactions between Beams & Condensed Matter- (1987-)