Investigating the role of hydrogen in silicon deposition using an energy-resolved mass spectrometer and a Langmuir probe in an Ar/H{sub 2} radio frequency magnetron discharge

Journal Article · Sun Jul 15 04:00:00 EDT 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4740508· OSTI ID:22085973

Mensah, S L; Naseem, Hameed H ^[1]; Abu-Safe, Husam ^[2]; Gordon, M H ^[3]

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1. University of Arkansas, Fayetteville, Arkansas 72701 (United States)
2. Lebanese American University, Byblos (Lebanon)
3. University of Denver, 2390 S. York St., Colorado 80208 (United States)

The plasma parameters and ion energy distributions (IED) of the dominant species in an Ar-H{sub 2} discharge are investigated with an energy resolved mass spectrometer and a Langmuir probe. The plasmas are generated in a conventional magnetron chamber powered at 150 W, 13.56 MHz at hydrogen flow rates ranging from 0 to 25 sccm with a fixed argon gas flow rate of 15 sccm. Various H{sub n}{sup +}, SiH{sub n}{sup +}, SiH{sub n} fragments (with n = 1, 2, 3) together with Ar{sup +} and ArH{sup +} species are detected in the discharge. The most important species for the film deposition is SiH{sub n} (with n = 0, 1, 2). H fragments affect the hydrogen content in the material. The flux of Ar{sup +} decreases and the flux of ArH{sup +} increases when the hydrogen flow rate is increased; however, both fluxes saturate at hydrogen flow rates above 15 sccm. Electron density, n{sub e}, electron energy, T{sub e}, and ion density, n{sub i}, are estimated from the Langmuir probe data. T{sub e} is below 1.2 eV at hydrogen flow rates below 8 sccm, and about 2 eV at flow rates above 8 sccm. n{sub e} and n{sub i} decrease with increased hydrogen flow but the ratio of n{sub i} to n{sub e} increases. The formation of H{sup +} ions with energies above 36 eV and electrons with energies greater than 2 eV contributes to the decrease in hydrogen content at hydrogen flow rates above 8 sccm. Analysis of the IEDs indicates an inter-dependence of the species and their contribution to the thin film growth and properties.

• OSTI ID: 22085973
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 19; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ARGON
ARGON IONS
DEPOSITION
ELECTRON DENSITY
ENERGY SPECTRA
EV RANGE
FLOW RATE
GAS FLOW
HIGH-FREQUENCY DISCHARGES
HYDROGEN
HYDROGEN IONS 1 PLUS
ION DENSITY
LANGMUIR PROBE
MAGNETRONS
MASS SPECTROMETERS
MHZ RANGE
PLASMA
RADIOWAVE RADIATION
SILICON
THIN FILMS