Workshop on Modeling Electron Transport for Applications in Electron and X-ray Analysis and Metrology

National Institute of Standards and Technology
Gaithersburg MD 20899
November 8-10, 2004

http://www.nist.gov/electron

In 1975 NIST held a Workshop on Monte Carlo electron-trajectory simulation techniques for electron-probe microanalysis and scanning electron microscopy. What was then an expensive and slow computer calculation can now be carried out many thousands of times faster with much more detail on any personal computer. Monte Carlo techniques have become a practical tool to support a variety of measurement problems in microscopy, microanalysis, radiation physics, and other applications.

NIST will hold a Workshop in 2004 to highlight progress and determine directions for future development of electron-simulation techniques and the needs for electron-interaction data. This Workshop will bring together experts in the physical theory and data that support the simulation techniques as well as scientists and engineers who develop models and obtain results for specific applications. Applications will include x-ray microanalysis of particles, rough and layered surfaces, Auger analysis of near-surface features, testing of matrix-correction procedures for bulk analysis, metrology of sub-micrometer scale features in SEM images, low-voltage and ultra-low-voltage microscopy simulation, radiation physics, etc. A planned poster session will include demonstrations of relevant software and databases.

This Workshop is sponsored by NIST, the AVS the Science and Technology Society, and the Microbeam Analysis Society.

1. Workshop Schedule

Monday, November 8
8.30 a.m. Bus departure from Gaithersburg Hilton Hotel
8.30 a.m. Registration
9.00 a.m. Welcome
9.05 a.m. Session 1
10.35 a.m. Break
11.00 a.m. Session 1 (continued)
12.30 p.m. Lunch
1.30 p.m. Session 2
3.00 p.m. Break
3.30 p.m. Session 2 (continued)
5.15 p.m. Bus departure for Gaithersburg Hilton Hotel
6.45 p.m. Departure from Gaithersburg Hilton Hotel for informal group dinner
7.00 p.m. Informal group dinner at Buca di Beppo (122 Kentlands Boulevard,
Gaithersburg)

Tuesday, November 9
8.30 am Bus departure from Gaithersburg Hilton Hotel
9.00 a.m. Session 3
10.30 a.m. Break
11.00 a.m. Session 3 (continued)
12.30 p.m. Lunch
1.30 p.m. Session 4
3.00 p.m. Break
3.20 p.m. Session 4 (continued)
5.45 p.m. Bus departure for Gaithersburg Hilton Hotel

Wednesday, November 10
8.30 a.m. Bus departure from Gaithersburg Hilton Hotel
9.00 a.m. Session 5: Poster Papers and Database/Software Demonstrations
11.00 a.m. Session 6: Panel Discussion
12.30 p.m. Lunch
1.15 p.m. Tours of Selected NIST Laboratories
3.00 p.m. Bus departure for Gaithersburg Hilton Hotel

2. Workshop Program

• Monday, November 8
  Session 1 (C. J. Powell, Chair)
  9.00 a.m. Welcome
  9.05 a.m. F. Salvat, “Cross Sections for Electron Interactions in Condensed
  Matter”
  9.35 a.m. Discussion
  9.50 a.m. S. Tanuma, “Experimental Determination of Electron Inelastic
  Mean Free Paths in Fourteen Elemental Solids in the 50 eV to
  5,000 eV Energy Range by Absolute Elastic-Peak Electron Spectroscopy”
  10.20 a.m. Discussion
  10.35 a.m. Break
  11.00 a.m. S. Tougaard, “Quantitative Characterization of Surface
  Nanostructures from Modeling the Transport of Photoelectrons
  and Auger Electrons”
  11.30 a.m. Discussion
  11.45 a.m. W. S. M. Werner, “Partial Intensity Approach to Electron
  Scattering Problems in the 50 eV-500 keV Energy Range”
  12.15 p.m. Discussion
  12.30 p.m. Lunch
• Session 2 (D. E. Newbury, chair)
  1.30 p.m. A. Jablonski, “Monte Carlo Simulation of Elastic and Inelastic Backscattering of Electrons from Surfaces”
  2.00 p.m. Discussion
  2.15 p.m. R. Gauvin, “X-Ray Microanalysis of Real Materials Using
  Monte Carlo Simulations”
  2.45 p.m. Discussion
  3.00 p.m. Break
  3.30 p.m. V. Hnizdo, “Monte Carlo Modeling of SEM X-Ray Emission from Respirable Particles”
  4.00 p.m. Discussion
  4.15 p.m. T. Nagatomi, “Monte Carlo Modeling of Electron-Excited X-Ray Emission from Bulk Materials and Thin-Film/Substrate Systems”
  4.45 p.m. Discussion
  5.15 p.m. Bus departure for Gaithersburg Hilton Hotel
• Tuesday, November 9
  Session 3 (J. A. Small, chair)
  9.00 a.m. D. C. Joy, “An Analysis of Secondary-Electron Yield Data for
  Monte Carlo Modeling”
  9.30 a.m. Discussion
  9.45 a.m. M. El-Gomati, “Why is it Possible to See Contrast between Two Differently Doped Semiconductor Regions in Low and Very Low Voltage SEM?”
  10.15 a.m. Discussion
  10.30 a.m. Break
  11.00 a.m. S.-Y. Lee, “A Flexible and Efficient Approach to Electron-Beam Proximity Effect Correction – PYRAMID”
  11.30 a.m. Discussion
  11.45 a.m. A. Seeger, “A Method for Simulation and Interpretation of SEM
  Images of Height Fields”
  12.15 p.m. Discussion
  12.30 p.m. Lunch

• Session 4 (M. T. Postek, chair)
  1.30 p.m. B. L. Thiel, “Modeling of Image Processes in the Low-Vacuum
  SEM”
  2.00 p.m. Discussion
  2.15 p.m. C. G. Frase, “Use of Monte Carlo Models in the Development
  and Validation of CD Operators”
  2.45 p.m. Discussion
  3.00 p.m. Break
  3.30 p.m. J. S. Villarrubia, “SEM Dimensional Metrology Using a Model-
  Based Library”
  4.00 p.m. Discussion
  4.15 p.m. N. T. Sullivan, “Model-Based CD-SEM Metrology at Low and
  Ultra-Low Landing Energies: Implementation and Results for
  Advanced IC Manufacturing”
  4.45 p.m. Discussion
  5.15 p.m. Bus departure for Gaithersburg Hilton Hotel
• Wednesday, November 10
  Session 5 (Poster Session and Demonstrations of Databases and Software)
  9.00 a.m. Poster Papers and Database/Software Demonstrations
  (1) P. M. Stone and Y.-K. Kim, "Calculation of Cross Sections for Ionization by
  Electron Impact of Atoms and Molecules Using the BEB Method"
  (2) M. A. Ali, Y.-K. Kim, and K. K. Irikura, "BEB Total Electron Impact Ionization
  Cross Sections of Halogen Atoms and Diatomic Halogen Molecules"
  (3) G. E. Scott and K. K. Irikura, “Total Ionization Cross Sections of Molecules
  Containing Heavy Elements (Z > 10): Two Implementations of BEB Theory
  Compared"
  (4) S. Tanuma, C. J. Powell, and D. R. Penn, “Calculations of Stopping Powers of
  50 eV to 30 keV Electrons in Ten Elemental Solids"
  (5) M. Suzuki, S. Tanuma, H. Yoshikawa, and S. Fukushima, "Observation of a Large Surface Excitation Effect from Silicon and Silicon Dioxide with X-ray
  Photoelectron Spectroscopy using Synchrotron Radiation"
  (6) P. J. Cumpson, "Rapid Monte Carlo Methods for Inhomogeneous Specimens in
  X-Ray Photoelectron Spectroscopy"
  (7) D. Y. Petrovykh, J. M. Sullivan, and L. J. Whiman, "Quantification of Discrete
  Sulfur and Oxide Layers on Sulfur-Passivated InAs by XPS"
  (8) J. Pavluch, L. Zommer, Y. Polyak, Z. Pekarek, A. Jablonski, B. Lesiak, T. Hrncir,
  and V. Nehasil, "Experimental and Model Study of the Rh/Al System by Means of EPES"
  (9) P. Carpenter, "A Comparison of Experimental EPMA Data and Monte Carlo Simulations"
  (10) N. W. M. Ritchie, "A New Monte Carlo Application for Complex Sample
  Geometries"
  (11) J. H. Fournelle, S. Kim, and J. H. Perepezko, "Evaluating Nb Ka Secondary Fluorescence by Experiment, Thin Film Software, and Monte Carlo"
  (12) A. Deal, X. Tao, and A. Eades, "EBSD Geometry in the SEM: Simulation and Representation"
  (13) G. S. Upadhyyaya, J. L. Shohet, and J. L. Lauer, "A Monte Carlo Simulation to
  Predict Vacuum Ultraviolet Induced Surface Potential on Silicon Nitride"
  (14) Z. H. Levine, "Scanning Transmission Electron Microscopy, Multiple Scattering,
  and Tomography,"
  (15) C. H. Claassens, J. J. Terblans, M. J. H. Hoffman, and H. C. Swart, "Kinetic
  Monte Carlo Simulation of Monolayer Gold Film Growth on a Graphite Substrate"
  (16) C. H. Claassens, J. J. Terblans, M. J. H. Hoffman, and H. C. Swart, " Kinetic
  Monte Carlo Simulation of Multi-Layer Gold Film Growth on a Graphite Substrate"
  (17) H. D. Joubert, H. C. Swart, and J. J. Terblans, "A Monte Carlo Model Utilizing
  Local Chemical Potentials for Simulating Segregation and Diffusion.
  Part 1 – Theory"
  (18) H. D. Joubert, H. C. Swart, and J. J. Terblans, "A Monte Carlo Model Utilizing
  Local Chemical Potentials for Simulating Segregation and Diffusion. Part 2 – Implementation"
  (19) S. Tougaard and F. Yubero, "Software Package for Calculation of Surface Effects
  in Electron Spectra (QUEELS)"
  (20) A. Jablonski, "MC Software for Calculation of Elastic Backscattering of
  Electrons from Surfaces"
  (21) D. E. Newbury and R. L. Myklebust, "Simulation of Electron-Excited Energy
  Dispersive X-ray Spectra with Desktop Spectrum Analyzer"
  (22) H. Demers (MAS Distinguished Scholar), P. Horny, and R. Gauvin, "WinX-Ray:
  A Monte Carlo Program for the Simulation of Electron and X-Ray Transport"
  (23) F. Salvat, X. Llovet, J. M. Fernandez-Varea, and J. Sempau, "PENELOPE:
  A General-Purpose Code for Simulation of Electron-Photon Transport"
  (24) W. Smekal, W. S. M. Werner, and C. J. Powell, "SESSA – Simulation of Electron
  Spectra for Surface Analysis"
  (25) C. J. Powell, A. Jablonski, and F. Salvat, "NIST Databases with Electron Elastic-
  Scattering Cross Sections, Inelastic Mean Free Paths, and Effective Attenuation
  Lengths"
• Session 6 (Panel Discussion of Opportunities and Needs, D. E. Newbury and
  J. S. Villarrubia, co-chairs)
  11.00 a.m. Opening Remarks by F. Salvat, D. C. Joy, and N. T. Sullivan
  11.30 a.m. Discussion
  12.30 p.m. Lunch
  1.15 p.m. Tours of Selected NIST Laboratories
  3.00 p.m. Bus departure for Gaithersburg Hilton Hotel
  

3. Publication of Proceedings

Authors of papers presented at the Workshop are invited to submit manuscripts for the Workshop Proceedings that will be published in a special issue of the journal Surface and Interface Analysis. Three copies of each manuscript should be submitted during the Workshop. Guidance on the preparation of manuscripts can be obtained from the Surface and Interface Analysis web site: http://www3.interscience.wiley.com/cgi-bin/jabout/2009/ForAuthors.html. The list of Authors and Titles can be downloaded as a pdf file and the manuscripts are scheduled to be published in the November 2005 issues of the journal.

4. Location of Workshop

The Workshop will be held in Lecture Room A of the NIST Administration Building in Gaithersburg, Maryland. Gaithersburg is a suburb in the Washington (DC) metropolitan area, and NIST is located approximately 40 km northwest from the center of the city. Participants can find information on NIST and on travel to NIST by going to the NIST web site (http://www.nist.gov). Click on "NIST visitor info/directions" to obtain additional information on travel to NIST from local airports, nearby restaurants, etc.

5. Travel to Washington

Three airports serve the greater Washington area. The most convenient airport to Gaithersburg for international flights is Washington Dulles airport, located about 50 km from Gaithersburg. International flights also arrive at the Baltimore-Washington airport located about 70 km from Gaithersburg. Domestic flights arrive at these airports and at Washington Reagan National airport, located close to the center of Washington. Detailed information about Dulles and Washington National airports and about Baltimore-Washington airport can be obtained online at http://www.metwashairports.com and http://www.bwiairport.com, respectively.

Participants who need visas to enter the United States should apply to their nearest US embassy or consulate as soon as possible. Due to long delays in securing visas to enter the U.S., it is strongly recommended that participants begin this process as early as possible to ensure approval. Please refer to http://www.national-academies.org/visas for information and assistance. Requests for letters of invitation, if needed, should be sent to Cedric Powell or Dale Newbury (see below). Citizens of certain countries do not require visas; for information on visa waivers see http://travel.state.gov/vwp.html. Citizens from these countries (including Austria, Denmark, France, Germany, Japan, Spain, and United Kingdom) can enter the U.S. without visas for visits up to 90 days and if they have machine-readable passports.

6. Travel to Gaithersburg, MD

Super Shuttle ((+1)-800-258-3826 or http://www.supershuttle.com) and Global Express ((+1) 800-777-1227 or http://www.globalexpresslimo.com) offer commercial van service from all three airports to the Gaithersburg area. You may make advance reservations by phone or online. The one-way fare from Dulles airport is approximately $35 (and a small tip to the driver is customary). Taxis are also available at all airports but will be much more expensive (the fare from Dulles airport will probably be around $75).

The Washington Metro system has subway (train) service to Gaithersburg and can be boarded at the Washington Reagan National Airport. (The subway does not serve the other two Washington-area airports.) Take the Yellow Line train marked "Mount Vernon Square" to the Gallery Place station, and transfer to a Red Line train marked "Shady Grove" to travel to the Shady Grove terminus of this line. Service is every 6 to 15 minutes, depending on the time of day. Travel time from National Airport to Shady Grove is approximately 1 hour. Taxis are available at the Shady Grove Station for travel to local hotels.

Rental cars are available at all three airports. From the Dulles airport, follow the Dulles Access Road for approximately 20 km to the Bethesda/Baltimore entrance ramp to I-495 north (Capital Beltway). From I-495 in Maryland, take the left fork to I-270 North (towards Frederick). Take exit 11 (route 124 east, Montgomery Village Avenue) and turn right at route 355, also called North Frederick Avenue (major intersection with traffic light). Turn right at next traffic light onto Perry Parkway. The Hilton Hotel is on the right. Note that there are 4 express lanes on I-270 and 2 separate collector/distributor lanes. Be aware of the signs with directions to enter the collector/distributor lanes from the express lanes prior to the desired exit.

Go to the NIST web page for driving directions from the other area airports (http://www.nist.gov).

7. Hotel Reservations

A block of rooms has been reserved at the Gaithersburg Hilton Hotel, 620 Perry Parkway, Gaithersburg, MD 20877 (Phone: (+1) 301-977-8900; Fax: (+1) 301-977-3450; internet: http://www.hilton.com/hotels/GAIGHHF) under the name "Modeling Electron Transport." Rooms can be reserved at the special rate of $109 (plus 12% tax), single or double, by phone, through the hotel web site (using MET as the Group/Convention code), or by faxing a completed reservation request to the hotel. Hotel reservations must be made prior to October 29, 2004. Please note that the hotel requires a credit card number in order to guarantee a reservation; if a participant is unable to satisfy this requirement, please contact Cedric Powell or Dale Newbury. A room reservation can be changed or cancelled without penalty if the hotel is notified by 4 p.m. on the day of scheduled arrival.

It is strongly recommended that all participants stay at the Hilton Hotel since this will simplify arrangements for participants to obtain badges (required for entry to NIST) and for travel to and from NIST.

8. Registration for the Workshop

There is no fee to attend the Workshop, but prior registration is required by NIST security in order for participants to be admitted to the NIST campus; on-site registration will not be possible. All participants need to complete an online registration form. Special badges will be prepared for Workshop participants and will be available at the Hilton Hotel on Sunday, November 7 between 6 and 8 pm. If a participant is unable to obtain a badge at this time, he or she will have to enter the Visitor Center at the main NIST gate and show a photo-ID to obtain a NIST entrance badge; the Workshop badge can be obtained later. Suitable photo-IDs are passports for visitors to the USA and state driver's licenses for US residents. Badges must be worn at all times on the NIST site.

9. Informal Welcome

Dale Newbury and Cedric Powell plan to be in the entrance lobby of the Hilton Hotel on Sunday, November 7 from 6.00 pm to 8.00 pm to welcome participants. Workshop badges will be distributed to participants at this time (and a photo-ID will be required for all participants not known personally to Dale and Cedric).

10. Travel to NIST from the Hilton Hotel (and return)

A NIST bus will be available to transport Workshop participants from the Hilton Hotel to NIST each morning. This bus will depart from the hotel at 8.30 a.m., and will return from NIST at 5.15 p.m. on November 8, 5.45 p.m. on November 9, and at 3.00 p.m. on November 10. All participants should wear and display their Workshop badges as they board the bus each morning in order to expedite entry to the NIST site. Participants should also bring photo-IDs (passports or US-state driver's licenses) since a guard may ask to see these on entry to NIST.

If any participants were unable to obtain their Workshop badges on Sunday, November 7, it will be necessary for the bus to stop at the NIST Visitor Center to obtain Visitors' entry badges (where photo-Ids will be required). Please note that the NIST bus may park in a section of the hotel parking lot not directly visible from the lobby area; it is recommended that participants exit the main lobby doors and turn left to look for the bus.

Participants driving to NIST from the Hilton Hotel should turn right on exiting the hotel parking lot, travel to the end of Perry Parkway, turn right at the traffic light onto Clopper Road, pass under the I-270 highway, and turn left at the second traffic light (Bureau Drive) for entry to the NIST site. Those participants with Workshop badges should drive in the left lane and stop for badge inspection by the guard (a photo-I.D. will also be inspected); participants without a badge should drive in the right lane and park at the Visitor Center where they should obtain a Visitor's entry badge. After driving about 30 meters to enter the NIST site, turn left at the T-junction and follow the road towards the 11-story Administration Building. Turn left at the first opportunity, and park in the large lot marked "Visitors." Participants should enter the lobby of the Administration Building and immediately turn left to reach Lecture Room A.

11. Informal Group Dinner

An informal group dinner will be held on Monday, November 8 at 7 pm at Buca di Beppo, 122 Kentlands Boulevard (just west of Great Seneca Highway), Gaithersburg, MD 20878 (301-947-2250). There will be a set menu of Italian dishes, and vegetarian choices will be available. A cash bar will be available for the purchase of beverages. It will be assumed that all Workshop registrants will attend the dinner unless notification is sent to Dale Newbury (dale.newbury@nist.gov) prior to November 4. Companions are welcome to attend the dinner if notification is sent to Dale Newbury, again by November 4.

12. Tours of Selected NIST Laboratories

We plan to offer tours of selected NIST laboratories. Details will be available at the workshop.

13. Visits to Places of Interest in the Washington Area

There are many places of interest in central Washington (e.g., White House, US Capitol, Smithsonian museums, National Gallery of Art, Washington Monument, Jefferson Memorial and Tidal Basin, Lincoln Memorial, etc. in the vicinity of the Mall), although visits inside the White House and US Capitol are currently restricted. No formal companions' program has been arranged, but guidance can be given on local attractions, opening hours, and travel by Metro. Companions will find it convenient to arrange for a hotel van to take them to the Shady Grove Metro station for travel by train to central Washington.

14. Other Information

Further information on the Workshop will be posted as it becomes available on the following web site: http://www.nist.gov/electron.

Autumn (fall) colors are an attractive part of the Washington scenery for several weeks in October. The colors typically peak in mid-October although the actual times and extent of the colors depend on earlier weather conditions. The fall colors may extend into early November.

The average maximum temperature in November is about 14o Celsius and the average minimum temperature is about 1o Celsius. Many days are clear and sunny although rain is possible. It is recommended that participants bring coats for use at night and in the event of rain.

Dale Newbury (dale.newbury@nist.gov)
Cedric Powell (cedric.powell@nist.gov)

Web Contact micro@nist.gov