Specific Process Knowledge/Characterization/XPS: Difference between revisions

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==XPS-ThermoScientific==
'''Unless anything else is stated, everything on this page, text and pictures are made by DTU Nanolab.'''
[[image:XPS instrument2.JPG|300x300px|right|thumb|The XPS system placed at Danchip (room 904, building 346).]]


'''All links to Kemibrug (SDS) and Labmanager Including APV and QC requires login.'''


'''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php?title=Specific_Process_Knowledge/Characterization/XPS click here]'''
<!--Checked for updates on 14/5-2018 - ok/jmli -->


A X-ray Photoecectron Spectroscopy (XPS) system can be used at Danchip. The system is a Thermo K-Alpha system, and is found in LabManager under the name XPS-ThermoScientific.
{{Template:Author-jmli1}}


==Elemental analysis==
==The XPS tools at DTU Nanolab==
The XPS technique can be used to do elemental analysis. A comparision about techniques and intsrumens used for elemental analysis at Danchip can be found on the page [[Specific Process Knowledge/Characterization/Element analysis|Element analysis]].


[[Image:XPS K-Alpha.jpg |frame|x300px|The K-Alpha from 2007 is one of the first instruments of this type that was produced.{{photo1}} ]]
[[Image:XPS Nexsa.png |frame|x300px|The Nexsa from 2019 is on the surface very similar to the K-Alpha. Its panels, however, hide a whole range of supplementary techniques.{{photo1}} ]]


==XPS technique==
XPS is a surface sensitive and non destructive technique used for analysis of the elemental composition.
Only the outermost atomic layers (some nanometers) are probed, but with an ion gun etch it is possibile to probe deeper laying layers.
In the XPS spectrometer system the probed samples are irradiated by photons with a specific energy, and the photoelectrons that leaves the sample are detected. The energy levels of the electrons are elemental specific, and by measuring the energy of the outgoing electrons, it is possible to detect which elements that are present in a sample.
The technique can be used for different purposes:
===Elemental composition===
[[image:Overview spectra Labadvisor.JPG|420x420px|left|thumb|XPS spectrum of a sample consisting of the elements silicon, oxygen and carbon.]]
Each element give a specific "finger-print" in the XPS spectrum. The electrons in the atoms have different binding energies for all elements, and when measuring a photoelectron spectrum over a wide range of energies, the main line from each element will be placed at a specific energy in the spectra.
Here is shown a spectra measured over the energy range 0-1350 eV, and characteristic lines from three elements (C,O and Si) are seen and indicated in the spectrum.
The instrument program can use this information to give an estimate of the sample composition, giving the atomic procentage of the different elements.
===Chemical state===
[[image:Si spectra Labadvisor.JPG|420x420px|left|thumb|XPS Si2p spectrum of Si sample]]


In the basement under the cleanroom two X-ray Photoelectron Spectroscopy (XPS) systems are installed back-to-back in the center of room 904. They are both manufactured by Thermofisher and they enable the users to perform elemental and chemical analysis of samples. The [[Specific Process Knowledge/Characterization/XPS/K-Alpha |XPS K-Alpha]] is a base technique instrument providing XPS analysis. The [[Specific Process Knowledge/Characterization/XPS/Nexsa |XPS Nexsa]] is an upgraded version with all options.
* [[Specific Process Knowledge/Characterization/XPS/K-Alpha|The XPS K-Alpha page]]
* [[Specific Process Knowledge/Characterization/XPS/Nexsa|The XPS Nexsa page]]


==Elemental analysis==
The XPS instrument enables elemental analysis, chemical state analysis on the sample surface or deeper down by a depth profiling. A comparison about techniques and instruments used for elemental analysis at DTU Nanolab can be found on the page [[Specific Process Knowledge/Characterization/Element analysis|Element analysis]].


More about the different possibilities of the XPS instrument is found here:


*[[Specific Process Knowledge/Characterization/XPS/XPS technique|The XPS technique]]
*[[Specific Process Knowledge/Characterization/XPS/XPS elemental composition|Elemental analysis]]
*[[Specific Process Knowledge/Characterization/XPS/XPS Depth profiling|Depth profiling]]
*[[Specific Process Knowledge/Characterization/XPS/Carbon contamination|Carbon contamination]]


*[[Specific Process Knowledge/Characterization/XPS/ExtDocs | Links to external material ]]
*[[Specific Process Knowledge/Characterization/XPS/Training | Links to instruction videos ]]


== Getting access to the XPS tools==


Click [[Specific Process Knowledge/Characterization/XPS/Access | '''HERE''' ]] to see information on how to get access to the XPS.


== Analyzing XPS spectra ==


The analysis of XPS spectra is an art in itself. It can be done using various software packages available on the internet. In the links below we will focus on two such examples, Avantage and CasaXPS.


*[[Specific Process Knowledge/Characterization/XPS/SoftwareInstall|How to access XPS software: Download/install or by access to server]]
*[[Specific Process Knowledge/Characterization/XPS/Processing|Processing XPS data with Avantage]]
*[[Specific Process Knowledge/Characterization/XPS/Export2CasaXPS | Export Avantage data to CasaXPS]]


==Techniques and option on the XPS tools==


{| border="2" cellspacing="0" cellpadding="1"
|-
!style="background:silver; color:black;" align="left" colspan="2"|Equipment
!style="background:silver; color:black;" align="left" |[[Specific Process Knowledge/Characterization/XPS/K-Alpha |XPS K-Alpha (Manufactured by Thermofisher)]]
!style="background:silver; color:black;" align="left" |[[Specific Process Knowledge/Characterization/XPS/Nexsa |XPS Nexsa (Manufactured by Thermofisher)]]
|-
!style="background:silver; color:black;" align="left" rowspan="2"|Purpose
|style="background:LightGrey; color:black"|Main
|style="background:WhiteSmoke; color:black"| XPS analysis using monochromated Al-Kα radiation at 1486.6 eV
|style="background:WhiteSmoke; color:black"| XPS analysis using monochromated Al-Kα radiation at 1486.6 eV
|-


 
|style="background:LightGrey; color:black"|Alternative/complementary
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
===Depth profiling===
 
[[Image:Stochiometry 20110510.JPG|425x425px|left|thumb|The composition of a NiCr as a function of film depth (etch time). The relationship between Cr and Ni is quite constant through the 70nm thick film. Measurements done with XPS-ThermoScientific. ]]
 
The analysis is made on a chosen spot on the sample surface (choosen with the system camera). The technique, is as written above, very surface sensitive and probes only the top nanometers of the sample.
 
With the ion beam gun on the system a etch of the sample can be done. The system measures the desired spectra, do a etch step and measures again. A series of etch cycles can be set up, measuring the composition of the sample through at different depths.
 
 
 
'''Example: NiCr film'''
 
As an illustration, a figure to the left, shows an elemental analysis through a metallic film consisting of Ni and Cr. The metallic layer was about 70 nm thick, and the atomic percentage of Ni and Cr was measured through the layer. 
 
In the graph, you see the atomic % as a function of etch depth, and it is possible to detect that the relationship between Ni and Cr is fairly constant through the metallic film.
 
==A rough overview of XPS-ThermoScientific characteristics==
 
{| border="2" cellspacing="0" cellpadding="20" |-
!style="background:silver; color:black;" align="left"|Purpose
|style="background:LightGrey; color:black"|Chemical analysis
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
* Probing elemental composition
* Work function measurements
* Chemical state identification
|style="background:WhiteSmoke; color:black"|
* Non destructive technique
* Work function measurements
* Surface sensitive
* [[Specific Process Knowledge/Characterization/XPS/UPS technique| Ultraviolet Photoelectron Spectroscopy (UPS) with He I and He II UV source]]
* Depth profiling possible by ion beam etch of sample
* [[Specific Process Knowledge/Characterization/XPS/ISS|Ion Scattering Spectroscopy or ISS]]
* [[Specific Process Knowledge/Characterization/XPS/REELS|Reflected Electron Energy Loss Spectroscopy or REELS]]
* Angular Resolved Ultraviolet Photoelectron Spectroscopy (ARUPS)
* [[Specific Process Knowledge/Characterization/XPS/Raman|Raman spectroscopy]]
|-
|-
!style="background:silver; color:black" align="left"|Performance
!rowspan="5" style="background:silver; color:black" align="left"| Performance
|style="background:LightGrey; color:black"|Spot size
|style="background:LightGrey; color:black"|Spot size
|style="background:WhiteSmoke; color:black"|Can be set between 30µm - 400µm
|style="background:WhiteSmoke; color:black"|XPS: 30µm - 400µm
|style="background:WhiteSmoke; color:black"|
* XPS: 10µm - 400µm
* Raman: > 15 µm
|-
|-
|style="background:silver; color:black"|
|style="background:LightGrey; color:black"|Pass energy
|style="background:LightGrey; color:black"|Probing depth
|style="background:WhiteSmoke; color:black"|10-400 eV
|style="background:WhiteSmoke; color:black"|Depending on probed element. Max probe depth lies within 10-200 Å.
|style="background:WhiteSmoke; color:black"|10-400 eV (XPS and ISS)
|-
|-
|style="background:silver; color:black"|
|style="background:LightGrey; color:black"|Analysis modes
|style="background:LightGrey; color:black"|Resolution
|style="background:WhiteSmoke; color:black"|Scanned and snapshot
|style="background:WhiteSmoke; color:black"|Dependent on probed elements. Concentrations down to about 0,5 atomic % can in some cases be detected.
|style="background:WhiteSmoke; color:black"|Scanned, snapshot and SnapMap
|-
|-
|style="background:silver; color:black"|
|style="background:LightGrey; color:black"|Charge compensation  
|style="background:LightGrey; color:black"|Charge compensation  
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"| Flood gun to be used for charge compensation of non conductive samples only
Flood gun can be used for charge compensation of non conductive samples
|style="background:WhiteSmoke; color:black"| Flood gun to be used for charge compensation of non conductive samples and for source of low energy electrons (REELS)
|-
|style="background:silver; color:black"|
|style="background:LightGrey; color:black"|Finding structures
|style="background:WhiteSmoke; color:black"|Choose measuring spot from camera image (magnified)
|-
|-
|-
!style="background:silver; color:black" align="left"|Depth profiling
|style="background:LightGrey; color:black"|Purpose
|style="background:WhiteSmoke; color:black"|With ion beam etch the top layer of the material can be removed, to do a depth profiling
|-
|-
|style="background:silver; color:black"|
|style="background:LightGrey; color:black"|Depth profiles
|style="background:LightGrey; color:black"|Ion beam size
|style="background:WhiteSmoke; color:black"|Depth profiles with single Ar ion bombardment
|style="background:WhiteSmoke; color:black"| About 0,3x1 mm
* Monoatomic energy range 200-3000 eV
 
|style="background:WhiteSmoke; color:black"|Depth profiles with MonoAtomic and Gas Cluster Ion Source ([[Media:MAGCIS.pdf |MAGCIS]])
* Monoatomic energy range 200-4000 eV
* Cluster mode energy range: 2-8 keV
*Cluster size range: 75-2000 atoms
|-
|-
!style="background:silver; color:black" align="left"|Substrates
!rowspan="2" style="background:silver; color:black" align="left"|Substrates / Samples
|style="background:LightGrey; color:black"|Substrate size
|style="background:LightGrey; color:black"|Sample holder size
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"| Maximum 60x60 mm
Max 60x60 mm
|style="background:WhiteSmoke; color:black"| Maximum 60x60 mm
|-
|-
|style="background:silver; color:black"|
| style="background:LightGrey; color:black"|Sample height
| style="background:LightGrey; color:black"|Substrate thickness
|style="background:WhiteSmoke; color:black"| Maximum 20 mm
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"| Maximum 20 mm
Max height about 20 mm
|-  
|-  
|}
|}

Latest revision as of 14:25, 8 May 2023

Unless anything else is stated, everything on this page, text and pictures are made by DTU Nanolab.

All links to Kemibrug (SDS) and Labmanager Including APV and QC requires login.

Feedback to this page: click here

Unless otherwise stated, all content on this page was created by Jonas Michael-Lindhard, DTU Nanolab

The XPS tools at DTU Nanolab

The K-Alpha from 2007 is one of the first instruments of this type that was produced.Photo: DTU Nanolab internal
The Nexsa from 2019 is on the surface very similar to the K-Alpha. Its panels, however, hide a whole range of supplementary techniques.Photo: DTU Nanolab internal


In the basement under the cleanroom two X-ray Photoelectron Spectroscopy (XPS) systems are installed back-to-back in the center of room 904. They are both manufactured by Thermofisher and they enable the users to perform elemental and chemical analysis of samples. The XPS K-Alpha is a base technique instrument providing XPS analysis. The XPS Nexsa is an upgraded version with all options.

Elemental analysis

The XPS instrument enables elemental analysis, chemical state analysis on the sample surface or deeper down by a depth profiling. A comparison about techniques and instruments used for elemental analysis at DTU Nanolab can be found on the page Element analysis.

More about the different possibilities of the XPS instrument is found here:

Getting access to the XPS tools

Click HERE to see information on how to get access to the XPS.

Analyzing XPS spectra

The analysis of XPS spectra is an art in itself. It can be done using various software packages available on the internet. In the links below we will focus on two such examples, Avantage and CasaXPS.

Techniques and option on the XPS tools

Equipment XPS K-Alpha (Manufactured by Thermofisher) XPS Nexsa (Manufactured by Thermofisher)
Purpose Main XPS analysis using monochromated Al-Kα radiation at 1486.6 eV XPS analysis using monochromated Al-Kα radiation at 1486.6 eV
Alternative/complementary
  • Work function measurements
Performance Spot size XPS: 30µm - 400µm
  • XPS: 10µm - 400µm
  • Raman: > 15 µm
Pass energy 10-400 eV 10-400 eV (XPS and ISS)
Analysis modes Scanned and snapshot Scanned, snapshot and SnapMap
Charge compensation Flood gun to be used for charge compensation of non conductive samples only Flood gun to be used for charge compensation of non conductive samples and for source of low energy electrons (REELS)
Depth profiles Depth profiles with single Ar ion bombardment
  • Monoatomic energy range 200-3000 eV
 Depth profiles with MonoAtomic and Gas Cluster Ion Source (MAGCIS)
  • Monoatomic energy range 200-4000 eV
  • Cluster mode energy range: 2-8 keV
  • Cluster size range: 75-2000 atoms
Substrates / Samples Sample holder size Maximum 60x60 mm Maximum 60x60 mm
Sample height Maximum 20 mm Maximum 20 mm
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