Characteristics of metal thin film deposition by laser ablation and laser-ablation-assisted-plasma-discharges

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:153897

Lash, J S; Spindler, H L; Gilgenbach, R M ^[1]; Doll, G L ^[2]

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1. Univ. of Michigan, Ann Arbor, MI (United States)
2. General Motors Research and Development Center, Warren, MI (United States)

Experiments are underway to deposit thin films of Al on Si substrates by two laser-ablative deposition processes: KrF excimer laser ablation and laser-ablation-assisted-plasma discharges. Laser ablation is accomplished by focusing a KrF excimer laser onto a pure solid aluminum target. Typical ablation fluences range from 4--10 J/cm{sup 2}. Through gated optical emission spectroscopy, the laser ablation plume optical emission is observed to contain only aluminum neutral transitions after approximately 100 ns. With the application of a 3.6 kV, 760 A discharge, the neutral atom plume is transformed into a plasma with the emission dominated by Al+ and Al{sup 2+} transitions. Spectroscopic measurements indicate an Al+ electronic temperature of 1 eV and an Al{sup 2+} electronic temperature of 3 eV. Since LTE is applicable for the observed emission, the free electron temperature of the discharge plasma is between 1 and 3 eV. A floating double-Langmuir probe measurement indicates a discharge electron temperature of 1 eV and an ion density of approximately 5 {times} 10{sup 14} cm{sup {minus}3}. Film characteristics under investigation include the material deposition rate and the particulate density and size. Initial studies find particulate diameters up to 20 microns with laser alone. Optical diagnostics have also been applied to monitor the ablation plasma plume and the discharge plasma during the deposition.

• OSTI ID: 153897
• Report Number(s): CONF-950612--; ISBN 0-7803-2669-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
ALUMINIUM IONS
ION DENSITY
LASER RADIATION
PHYSICAL VAPOR DEPOSITION
PLASMA DIAGNOSTICS
SILICON