Application of scanning micro-tip and UHV Kelvin probes in surface and material characterisation.

In this thesis we present work utilising the scanning Kelvin probe (SKP) for surface potential mapping and monitoring changes in work function due to environmental influences in ambient and UHV conditions. The SKP is a truly non-contact technique which determines local work function changes and surface states on conductors, semiconductors and even insulators. It measures the contact potential difference of a sample relative to the tip. We compare the reproducibility of freshly cleaved highly orientated pyrolytic graphite (HOPG) with freshly sputtered Gold surfaces for ambient environment tip calibration. A new actively shielded upsilon-tip (200 upsilon m diameter) is introduced to increase spatial resolution for CPD and topographic scans in order resolve features in the upsilon m region. The upsilon-SKP has been applied in ambient to multi-crystalline Si; we show variations in work function between different poly-types, surface charging effects and series resistance (shunts). For comparison single-crystalline germanium and gallium arsenide is investigated by means of surface photovoltage measurements. We have utilised a UHV Kelvin probe to optimise high and low work function materials for hyperthermal surface ionisation (HSI), a new mass spectrometer technique that reduces ion fragmentation.

Grantor dc:publisher.institution

Robert Gordon University

Year dc:date.issued

2002

Author dc:creator

• Dirscherl, Konrad Maximilian

Advisor dc:contributor.advisor

• I. Baikie

• Scanning Kelvin probe (SKP)
• Non-contact technique
• Highly orientated pyrolytic graphite (HOPG)
• Upsilon-tip
• Surface photovoltage
• Hyperthermal surface ionisation (HSI)
• Mass spectrometer
• Ion fragmentation

Language dc:language

en

Identifier

oai:rgu-repository.worktribe.com:2807363
https://doi.org/10.48526/rgu-wt-2807363

OAI identifier oai:identifier

oai:rgu-repository.worktribe.com:2807363