Stanford SNSF
Stanford Nano Shared Facilities
Stanford Nano Shared Facilities

XPS: PHI VersaProbe 4

Jump To: Overview | Contact Information | Getting Started and Training Information | Resources

Overview

VersaProbe 4

The newest addition to SNSF's Surface Analysis Lab is the VersaProbe 4 XPS (Physical Electronics, Inc.).  The VersaProbe 4 combines the most popular features of the VersaProbe 3 with improved sensitivity and additional capabilities.

Additional VP4 Capabilities:

  • 2" Transfer Vessel: For samples needing air-free transfer, the VP4 can accommodate the 2" platen in the transfer vessel for analysis of more samples in one session.
  • Double-window Intro chamber: An ex-situ camera is mounted over a second window so a top-down photo is possible while using the transfer vessel.
  • 4-contact Heating/Cooling Stage: In-situ heating/cooling experimentation is possible through a temperature range of -120oC to 500oC.  Specialized sample holder has 4 contact points connected through stage control for in-situ electrochemical experimentation.
  • Gas Cluster Sputtering with Cluster Size Measurement tool:  Advanced Gas Cluster Ion Beam Gun (GCIB) has the ability to tune Ar+ cluster size and therefore milling rate for specific applications.
  • Reflection Electron Energy Loss Spectroscopy (REELS): The reflected electron energy loss spectrum can reveal details about excited atomic states, valence band transitions, and material bandgap.  This technique is used to measure bandgap, detect hydrogen content, and distinguish sp2/sp3 carbon bonds.
  • Ultraviolet Photoelectron Spectroscopy (UPS): He I or He II photons are used to produce a spectrum that can reveal the ionization energy and highest occupied molecular orbital (HOMO) of a material.
  • Low Energy Inverse Photoelectron Spectroscopy (LEIPS): LEIPS provides the lowest unoccupied molecular orbital (LUMO) from which electron affinity can be determined.  UPS and LEIPS in combination can provide important information about the valence band structure of semiconductor materials.

Basic XPS Capabilities:

  • Detection limits (all elements except H and He): ~ 0.01 monolayer, or ~ 0.1% bulk
  • Measurement depth: 10 - 50 Å;
  • Spot sizes: 10um - 200 um or 1400 um x 100 um with High Power setting.
  • Sample size: Samples must fit a 1" or 2" diameter platen; max 5 mm thick.
  • Spectrometer: Monochromatized Al(Kα) Source; Vacuum ~ 1.2x10E(-7) Pa

 

Contact Information

Juliet Jamtgaard
(650) 736-1256

Getting Started and Training Information

Training for the VersaProbe 4 is open to users who need its special capabilities such as UPS, LEIPS, REELS, and air-free transfer, as well as to qualified VersaProbe 3 users.

In order to become a qualified user on the PHI VeraProbe 4, you need to follow each of these steps in the order as listed here:

  1. Complete the process to become a lab member of SNSF and follow the instructions to activate a Badger account.
  2. Join EdX and take all 9 parts of the PHI XPS VersaProbe 3 online training module, including all 9 quizzes. Because VersaProbes 3 and 4 use identical software and follow similar procedures, both tools require the VersaProbe 3 XPS EdX modules to be completed before in-person training.
    • Click on this link and navigate to the XPS section, under Surface Characterization & Analysis
  3. Send an email to Juliet Jamtgaard to request training.
  4. One or more 1-on-1 trainings may be necessary for full qualification.

Training modules for VersaProbes 3 and 4 are now available on EdX. 

Anyone interested in general XPS information is welcome to take the first two modules in the XPS VersaProbe 3 series, which are entitled “Introduction to XPS” and “XPS: Background and Theory.” 

To complete VersaProbe 4 training and qualification, there are 7 more modules and quizzes in the series. Please start with the link above and take the two introductory modules. Then, proceed to the remaining 7 modules and 7 quizzes listed under the “PHI VersaProbe III Remote Training at Stanford” heading. 

Once you have completed the 9-part series, the next step is one or more 1-on-1 sessions on the instrument with your own samples. 

Resources

User Guides:
Instrument Policies
PHI VersaProbe 4 User Guide
XPS Multipak Manual
CasaXPS Manual

XPS Background Info: There are numerous texts discussing the use of XPS. Some useful examples are:

  • Electron Spectroscopy: Theory, Techniques and Applications. C. R. Brundle and A. D. Baker, eds. (a 5 volume series)
  • Practical Surface Analysis, D. Briggs and M. P. Seah eds.
  • Handbook of XPS, C. D. Wagner (published by Physical Electronics, Inc.)
  • Or try http://www.york.ac.uk/org/esca/tech/xps.html.