Product

PHI Quantes dual scanning X-ray photoelectron microprobe

 

Introduction

The PHI Quantes dual-scan XPS scanning probe is developed based on the PHI Quantera II system. The key feature of Quantes is on the dual monochormated X-ray source with same analysis positon for Al Ka and Cr Ka. Compared with conventional Al Ka X-ray source, Cr Ka X-ray source with energy of 5.4 KeV can detect depth information of about 30nm down from the surface, and obtain spectrum with a wider energy range. Hence achieving the world class XPS with Inner, Deeper and Wider information. The PHI Quantes with its breakthrough performance is expected to play a very important role in surface analysis research from now to many years in upcoming technology world.

 

Benefits

Deeper in Information Depth

As below graph indicated, the elastic mean free path for Cr Ka X-ray is almost 3X deeper than Al Ka X-ray. And this is based on the physics rather than one has to do sample etching or sputtering to reach to such deeper layer information. This change in physical phenomena from Cr Ka X-ray together with still flexibility that Al Ka X-ray is still available inside the one single system had expand the PHI Quantes analysis capabilities beyond expectation.

 

 

As above example when analyzing the same sample with a 10nm SiO2 on top of Si substrate sample, the Al Ka X-ray result hardly review any signal of the Si-metal while from Cr Ka data the Si-metal is easily detected.

 

Detection of inner core electrons with wider energy spectrum

Inner core electrons can be detected by Cr Ka, which is not available with Al Ka. Those inner core electrons would appear in the higher binding energy range like below spectrums illustrated.

 

 

Key Features

 

 

Above is an illustration diagram of the PHI Quantes Dual X-ray design.

 

  • Monochromatic Dual X-ray Source,Cr Ka(5.4 KeV) and Al Ka(1.5 KeV) in one system.
  • Cr Ka XPS provides 3X greater information depth versus Al Ka

 

 

  • As above pictures shown, the XPS analysis position for Cr Ka and Al Ka can be aligned basically as identical spot.
  • The PHI Quantes has a built-in proven Turn-key Charge Neutralization design.
  • Both Cr Ka and Al Ka XPS provide Sensitivity Factors for quantification on the PHI Quantes.

 

Options

  • Sample Positioning Station (SPS)
  • Auxiliary chamber for various kinds of sample preparation needs
  • Hot/cold stage
  • Gas Cluster Ion Beam for sputtering depth profile for organic materials.

 

Applications

  • Application example 1 – Transition Metal and Metal-Oxide analysis

 

 

In XPS, excited photoelectrons kinetic energy sometimes overlap with the emitted Auger electrons energy, as both generated by the incident X-ray. By switching between Cr Ka and Al Ka, this overlapping can be avoided very clearly and easily as seeing example below the Fe-Cr alloy survey spectrum. This is highly unique feature of the PHI Quantes.

From narrow spectra of Fe2p and Cr2p shown below, one can see that the ratio between Cr-Oxide to Cr-metal as well as Fe-Oxide to Fe-metal are opposite between the XPS analysis by each of Cr Ka X-ray and Al Ka X-ray. By such detailed study, one can then conclude the Oxide state of the metal is mainly in the top surface or even in some way be able to estimate about such Oxide-thickness without actually damaging the sample by the need of, for example, ion sputtering causing analysis uncertainties.

 

 

  • Application example 2 – Discolored Copper electrode or Pad samples

Below showing a Copper electrode sample with some discoloring problem under an optical microscope.

 

The sample is analyzed in the PHI Quantes, and the result is shown below.

 

 

For result by Cr Ka XPS on area (A,B), one can see obvious ratio difference of Cu2+ and Cu+. But from result by Al Ka XPS on area (a,b), basically no significant difference in chemical state and composition ratio.

These results indicate oxidation state of Cu is mainly Cu2O on both of bright and dark color area. However, CuO is more observed by Cr Ka on the dark area, which imply the CuO more exists underneath the Cu2O.

 

  • Application example 3 – Buried interface

As below diagram shown, we used the PHI Quantes to analyze a multi-layer thinfilm. In the diagram, we also show by BLUE, GREEN, RED as the analysis depth difference between XPS analysis by Al Ka or Cr Ka X-ray with different TOA (Take-off Angle) too.

 

 

Below is the analysis result. One the left picture, one can see that Al Ka cannot detect any Cr2p signal at all which is after 13.4nm in depth after the Y2O3 layer. Only by using Cr Ka X-ray we can then detect the Cr by XPS analysis. Furthermore, the right picture shows that at different TOA, the Cr2p peak review different ratio between the Cr-metal and Cr-Oxide, implying to the research person that the Oxide is located more between the interface of Y2O3-to-Cr rather than Cr-to-Ti later. Such result obtained without damaging sample could help analyst review the sample information much more accurately and target to lead to much more valuable research works & results.

 

 

Contact CoreTech Marketing & Service team now.

 

For more details, please visit our Brochure or Application Notes pages.

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