Low energy Ar{sup +} bombardment of GaN surfaces: A statistical study of ion reflection and sputtering

Journal Article · Wed Sep 15 04:00:00 EDT 2010 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3480344· OSTI ID:22051157

Despiau-Pujo, Emilie; Chabert, Pascal ^[1]

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1. Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau (France)

Statistical molecular dynamics simulations are performed to analyze the sputtering of w-GaN (wurtzite) and z-GaN (zinc blende) surfaces under 100 eV Ar{sup +} ion bombardment. Ion reflection and physical sputtering mechanisms are investigated as a function of the ion impact angle and the crystalline nature of samples. The probability of ion reflection is lower for the w-GaN phase and increases with the angle of incidence {theta}{sub i}. As {theta}{sub i} becomes more glancing, the reflected ions become more energetic and their angular distribution tends to narrow. The sputtering yields of w-GaN and z-GaN surfaces are maximum for {theta}{sub i}=45 deg. For near-normal incidence, the probability of sputtering is smaller for the w-GaN phase, suggesting that the atomic arrangement in the pristine state modifies the characteristics of the momentum transfer occurring between the ion and the surface atoms during the collision cascade. Atomic nitrogen sputters preferentially and represents 87% to 100% of sputtered species due to its lower mass. These statistical results differ from the predictions of continuous ion bombardment simulations since the surfaces are not allowed to evolve self-consistently during the gathering of impact statistics.

• OSTI ID: 22051157
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 5 Vol. 28; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR DISTRIBUTION
ARGON IONS
CRYSTAL STRUCTURE
EV RANGE
GALLIUM NITRIDES
INCIDENCE ANGLE
ION BEAMS
MOLECULAR DYNAMICS METHOD
MOMENTUM TRANSFER
NITROGEN
PROBABILITY
REFLECTION
SPUTTERING
SURFACES
ZINC SULFIDES