The document describes the capabilities of an X-ray photoelectron spectroscopy (XPS) instrument called the K-Alpha XPS from Thermo Scientific. The K-Alpha provides high throughput analysis with micrometer-scale spatial resolution. It features an aluminum anode X-ray source for high chemical state resolution and a focused ion beam for sample cleaning and depth profiling. The document outlines how XPS can be used to identify elements, quantify elemental composition, and determine chemical bonding states at surfaces.

1. NANOSTRUCTURE SOFT MATERIALS LABORATORY – LMN
email: Juliana.bernardes@lnnano.cnpem.br
Juliana da Silva Bernardes
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)

2. NANOSTRUCTURE SOFT MATERIALS LABORATORY – LMN
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)
K-ALPHA XPS – THERMO SCIENTIFIC
• High throughput (sensitivity, automation,
multi-sample operation, minimum user
intervention)
• High performance
• Small footprint
• Low cost of ownership
• Ion gun operating range (100 eV – 4 keV)
• Camera system
K-Alpha key features & benefits:
• Al Ka X-ray Monochromator  High chemical state resolution
• Micro-focused X-ray probe  Complete analysis of insulating materials
• Advanced viewing optics  Precise feature and defect alignment
• Focused Profiling Source  Multilayer and depth analysis
• Turn-key Neutralisation source  Accurate small area analysis
• 128 Channel Detection system  For rapid parallel snapshot-acquisition

3. NANOSTRUCTURE SOFT MATERIALS LABORATORY – LMN
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)
Camera for
‘Platter View’
Hemispherical
Analyser
X-ray
Source
Camera for
‘Reflex View’
Reflex
Optics
Loadlock
Analysis
Position
Camera for
Height Setting
UHV System
Allows longer photoelectron path length
Ultra-high vacuum keeps surfaces clean
Electron analyser
Lens system to collect photoelectrons
Analyser to filter electron energies
Detector to count electrons
X-ray source
Typically Al Ka radiation
Monochromated using quartz crystal
Low-energy electron flood gun
Analysis of insulating samples
Ion gun
Sample cleaning
Depth profiling
For polymers, cluster ion sources may be
required
Flood gun
A beam of low energy electrons
XPS INSTRUMENTATION

4. NANOSTRUCTURE SOFT MATERIALS LABORATORY – LMN
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)
SAMPLE HOLDERS
• Large sample holder
– Maximum analysis area 60 x 60 mm
– Maximum thickness 20 mm
• Removable sample plate
– Mount samples while previous set is being analysed
• Holder for rotation depth profiles
- Azimuthal & compucentric depth profiling
• Holder for powders
• Holder for ARXPS (optional
sample tilt module)

5. NANOSTRUCTURE SOFT MATERIALS LABORATORY – LMN
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)
SAMPLE HOLDERS
• K-Alpha has a simple sample
loading process which ensures a
safe transfer of the sample holder
into the analysis chamber.
• The load-lock ion gauge monitors
the pressure and transfers the
samples when safe to do so.

6. NANOSTRUCTURE SOFT MATERIALS LABORATORY – LMN
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)
SURFACE ANALYSIS
Elemental identification
• Which elements are present?
• Can detect all elements except for H
Elemental quantification
• How much of an element is present?
• Detection limit >0.05% for most elements
• Allows determination of stoichiometry
Chemical state identification and quantification
• Bonding states for each element
• Chemical structure

7. NANOSTRUCTURE SOFT MATERIALS LABORATORY – LMN
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)
SURFACE ANALYSIS
Elemental identification
• Which elements are present?
• Can detect all elements except for H
Elemental quantification
• How much of an element is present?
• Detection limit >0.05% for most elements
• Allows determination of stoichiometry
Chemical state identification and quantification
• Bonding states for each element
• Chemical structure