• Briggs & Seah, Chap. 3 (Spectral Interpretation); Chap.5 (Quantification of XPS and AES).
• Woodruff & Delchar Chap. 3.3: AES
• EscaLab Operating Instructions, chapter on SEM electron gun
• VGS5000 Users Manual Esca: Chap. 2 (Intro to VGS5000); Chap.3. (Set up an experiment)
• Burhop and Assad, Theory of Auger electron emission

Introduction to electron-excited Auger emission spectroscopy of clean transition metals. Use of fixed-analyzer-transmission (FAT) or constant-retard ratio (CRR) mode for measurement of N(E). Incident beam energy dependence of Auger electron yield. Line-shape comparison of electron vs. Photon-excited Auger spectroscopy.

1. Sample preparation

   This experiment should be performed on a sputter-cleaned surface. Use the results of Experiment #1 to determine how to achieve this.

2. Auger spectroscopy of clean surface

   Using a low magnification (100x) rastering beam (not fixed spot), acquire a high quality N(E) Auger-electron distribution with a 10 keV incident beam energy. You may use imaging to verify the analysis location, with instructors assistance.

3. Identify spectral features of the transition metal, as well as any remaining impurities, and label them with the appropriate Auger signature (e.g. KLL, LVV, etc.)
4. Compare graphically the electron-excited Auger emission spectra with equivalent lines from your XPS data.
5. Differentiate numerically your N(E) spectrum and compare to the tabulated dN/dE spectrum in the lab handbooks.
6. Discuss the similarities and/or difference between the measured electron and photon excited AES (Auger electron spectra).

1. Measure quantitatively the Auger yield for a high energy (500-1000eV) AES, as a function of beam energy, for (say), 2, 4, 7 and 10 keV. Be sure to determine the incident beam current at each energy.
2. Graph the AES peak intensity vs. Beam energy (use N(E) mode, not derivatives, and subtract the background). Note that this only has meaning if you normalize to incident beam current. Incident beam current usually strongly depends on the incident beam energy. The theoretical maximum AES yield occurs in the vicinity of K_o=4xK_AES

Under certain circumstance, the incident high energy electron beam can cause chemical modification of the surface you are studying. This is very dependent on the sample and its surface condition.

1. Sputter sample clean (may only require a short time).
2. Acquire wide-area AES (part 2 may satisfy this).
3. Place a beam in POINT mode at high magnification (say 1000X), to stop the beam with a small spot size. Take POINT spectra after 1, 10, and 25 minutes of leaving the beam in POINT mode.
4. COMPARE the intensities of (any) impurities (typically carbon) as a function of time.
5. COMPUTE the incident power density used in this part of the experiment (W/cm²). The spot size is dependent on the incident current. It ranges from about 0.2 micron to over 10 micron. Consult the instructor and manuals.