Welcome to the Computational Mechanics Center

Invited Presentations

1.	“Magnification Control -- Temperature Analysis” presented at the DARPA Technical Interchange Meeting (TIM) at IBM in Burlington, VT on June 24, 1997.
2.	“Stencil Mask Modeling,” presented at Ion Microfabrication Systems (IMS) in Vienna, Austria on September 22 and 23, 1997.
3.	“Modeling of Mask Structures for Ion Beam Lithography,” presented at the University of Stuttgart in Stuttgart, Germany on September 26, 1997.
4.	“Mechanical Modeling of SCALPEL Masks,” presented at the SEMATECH Program Review at Lucent Technologies in Murray Hill, NJ on October 21, 1997.
5.	“Mechanical Modeling of Stencil Masks,” presented at the SEMATECH Program Review of the European Ion Beam Projection Lithography (IPL) Project in Hopewell Junction, NY on October 23, 1997.
6.	“The Virtual Mask Laboratory: An Overview of Advanced Mask Modeling,” presented at the DARPA Program Review in San Antonio, TX on January 29, 1998.
7.	“Mask Stability Program,” presented at SVG Lithography in Wilton, CT on March 25, 1998.
8.	“Advanced Mask Design for 0.1 mm Technology,” presented at the IEEE Lithography Workshop in Banff, Canada on April 15, 1998.
9.	“Mask Stability Program - Optical Masks,” presented at MIT - Lincoln Labs in Lexington, MA on April 22, 1998.
10.	“Stencil Mask Modeling and Simulation,” presented at the SEMATECH Next Generation Lithography (NGL) Critical Review Meeting in San Francisco, CA on May 6, 1998.
11.	“Modeling of Membrane Masks,” presented at the 1998 Gordon Research Conference on the Chemistry and Physics of Nanostructure Fabrication in Tilton, NH on June 23, 1998.
12.	“Stencil Mask: Finite Element Modeling,” presented at the International Meeting on Ion Projection Lithography in Vienna, Austria on September 18, 1998.
13.	“Modeling and Simulation of Membrane Distortions in NGL Masks,” presented at the 1998 International Conference on Micro- and Nano- Engineering in Leuven, Belgium on September 24, 1998. (This was an invited Plenary Talk.)
14.	“Simulations of Mask and Wafer Distortions,” presented at ASM Lithography in Veldhoven, The Netherlands on September 25, 1998.
15.	“Modeling of SCALPEL and Stencil Masks” presented at The Third International Workshop on High Throughput Charged Particle Lithography in Waikoloa, Hawaii on November 13, 1998.
16.	“Mask Distortion Modeling” presented at Mask Advisory Steering Council Mtg. in Ft. Lauderdale, FL on January 13, 1999.
17.	“Lithographic Mask Modeling” presented at International SEMATECH in Austin, TX on January 29, 1999.
18.	“Stencil Mask Modeling” presented at the International Ion Projection Beam Lithography Meeting at the University of Kassel in Kassel, Germany on February 17, 1999.
19.	“Advanced Mask Accuracy and Stability Study” presented at Sandia National Laboratory in Livermore, CA on February 22, 1999.
20.	“Advanced Mask Modeling” presented at the DARPA Programs Review in Arlington, VA on April 13, 1999.
21.	“Thermomechanical Modeling of Advanced Optical Reticles” presented at Intel Corporation in Santa Clara, CA on April 30, 1999.
22.	“Cross-Cutting Issues for NGL Masks” presented at The 43rd International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIPBN ‘99) in Marco Island, FL on June 4, 1999.

Additional Symposium Presentations:

23. “Thermomechanical Response for 157 nm Optical Reticles” presented at the First International Symposium on 157 nm Lithography in Dana Point, CA on May 10, 2000.

24. “Effect of Chrome Stress on Pattern Transfer Mechanical Distortions” presented at the First International Symposium on 157 nm Lithography in Dana Point, CA on May 10, 2000.

25. “Pellicle-Induced Distortions in Advanced Optical Reticles” presented at the First International Symposium on 157 nm Lithography in Dana Point, CA on May 11, 2000.

Research Reviewed Journal Publications:

1.	"Pattern Placement Errors in Mask Membranes,” Journal of Vacuum Science and Technology B, Vol. 15, No. 6, pp. 2249-2254, (A. Fisher, M. Laudon, R. Engelstad and E. Lovell), 1997.
2.	“Mechanical Modeling of Projection Electron-beam Lithography Masks,” Japanese Journal of Applied Physics, Vol. 36, Part 1, No. 12B, pp. 7564-7569, (G. Dicks, R. Engelstad, E. Lovell and J. Liddle), 1997.
3.	“Stencil Mask Distortion Control Using Nonsymmetric Perforation Rings,” Microelectronic Engineering, Vol. 41/42, pp. 225-228, (M. Sprague, W. Semke, R. Engelstad, E. Lovell, A. Chalupka, H. Löschner and G. Stengl), 1998.
4.	“Mechanical Modeling of Ion Beam Lithography Masks, Microelectronic Engineering, Vol. 41/42, pp. 245-248, (A. Fisher, R. Tejeda, M. Sprague, R. Engelstad and E. Lovell), 1998.
5.	“X-ray Mask Distortions during E-beam Patterning,” Microelectronic Engineering, Vol. 41/42, pp. 283-286, (B. Shamoun, M. Sprague, F. Bedford, R. Engelstad and F. Cerrina), 1998.
6.	“P-N Junction-Based Wafer Flow Process for Stencil Mask Fabrication,” Journal of Vacuum Science and Technology B, Vol. 16, No. 6, pp.3592-3598, (I. Rangelow, F. Shi, B. Volland, E. Soßna, A. Petrashenko, P. Hudek, R. Sunyk, I. Kostic, J. Butschke, F. Letzkus, R. Springer, A. Ehrmann, G. Gross, R. Kaesmaier, A. Oelmann, G. Unger, A. Chalupka, E. Haugeneder, G. Lammer, H. Löschner, R. Tejeda, E. Lovell and R. Engelstad), 1998.
7.	“Assessment of Thermal Loading-Induced Distortions in Optical Photomasks due to E-Beam Multipass Patterning,” Journal of Vacuum Science and Technology B, Vol. 16, No. 6, pp. 3558-3562, (B. Shamoun, R. Engelstad and D. Trost), 1998.
8.	“Optimization of the Temperature Distribution across Stencil Mask Membranes under Ion Beam Exposure,” Journal of Vacuum Science and Technology B, Vol. 16, No. 6, pp. 3602-3605, (B. Kim, R. Engelstad, E. Lovell, A. Chalupka, E. Haugeneder, G. Lammer, H. Löschner, J. Lutz and G. Stengl), 1998.
9.	“Pattern Transfer on Mask Membranes,” Journal of Vacuum Science and Technology B, Vol. 16, No. 6, pp.3572-3576, (A. Fisher, R. Engelstad, E. Lovell and D. Puisto), 1998.
10.	“Dynamic Analysis of a SCALPEL Mask during Electron Beam Exposure,” Journal of Vacuum Science and Technology B, Vol. 16, No. 6, pp. 3587-3591, (W. Semke, R. Engelstad, E. Lovell and J. A. Liddle), 1998.
11.	“Stress Relief Structures for Ion-Beam Projection Lithography Masks,” Microelectronic Engineering, Vol. 46, pp. 481-484, (R. Tejeda, R. Engelstad, E. Lovell, E. Haugeneder and H. Löschner), 1999.
12.	“Finite Element Simulation of Ion-Beam Lithography Mask Fabrication,” Microelectronic Engineering, Vol. 46, pp. 485-488, (R. Tejeda, G. Frisque, R. Engelstad, E. Lovell, E. Haugeneder and H. Löschner), 1999.
13.	“Mask Membrane Distortions due to Pattern Transfer for Electron-Beam Lithography (SCALPEL) Masks,” Microelectronic Engineering, Vol. 46, pp. 283-286, (G. Dicks, R. Engelstad, E. Lovell and J. Liddle), 1999.
14.	“Initial Wafer Heating Analysis for a SCALPEL Lithography System,” Microelectronic Engineering, Vol. 46, pp. 235-238, (S. Stanton, J. Liddle, G. Gallatin, B. Kim and R. Engelstad), 1999.
15.	“Modeling and Simulation of Membrane Distortions in Next Generation Lithography (NGL) Masks,” Microelectronic Engineering, Vol. 46, pp. 23-26, (R. Engelstad, E. Lovell, G. Dicks, A. Fisher and R. Tejeda), 1999. (This was an invited paper.)
16.	“Thin Film Stress Mapping Using an Integrated Sensor,” Journal of Vacuum Science and Technology B, Vol. 17, No. 6, pp. 2714-2718, (M. Schlax, A. Jachim, R. Engelstad, E. Lovell, J. Liddle and A. Novembre), 1999.
17.	“Mechanical and Thermal Modeling of the SCALPEL Mask,” Journal of Vacuum Science and Technology B, Vol. 17, No. 6, pp. 2878-2882, (C. Martin, W. Semke, G. Dicks, R. Engelstad, E. Lovell, J. Liddle and A. Novembre), 1999.
18.	“Finite Element Analysis of SCALPEL Wafer Heating,” Journal of Vacuum Science and Technology B, Vol. 17, No. 6, pp. 2883-2887, (B. Kim, R. Engelstad, E. Lovell, S. Stanton, J. Liddle and G. Gallatin), 1999.
19.	“Comparison of Silicon Stencil Mask Distortion Measurements with Finite Element Analysis,” Journal of Vacuum Science and Technology B, Vol. 17, No. 6, pp. 3107-3111, (A. Ehrmann, T. Struck, A. Chalupka, E. Haugeneder, H. Löschner, J. Butschke, M. Irmscher, F. Letzkus, R. Springer, A. Degen, I. W. Rangelow, F. Shi, E. Sossna, B. Volland, R. Engelstad, E. Lovell, and R. Tejeda), 1999.
20.	“Modeling Pattern Transfer in Ion-Beam Lithography Masks,” to appear in Microelectronic Engineering, (G. Frisque, R. Tejeda, R. Engelstad and E. Lovell), 2000.
21.	“Simulating the Mechanical Response of EPL Masks,” to appear in the Journal of Vacuum Science and Technology B, (A. Jachim, R. Engelstad, E. Lovell, P. Mangat and W. Dauksher), 2000.
22.	“Mechanical Analysis of the PLASMAX Particle Removal Process for Optical and NGL Masks,” Journal of Vacuum Science and Technology B, (W. Semke, E. Weisbrod, R. Engelstad, E. Lovell, J. Festa and B. Bailey), 2000.
23.	“In-Plane Gravity Loading of a Circular Membrane,” to appear in the Journal of Applied Mechanics, (R. Tejeda, E. Lovell and R. Engelstad), 2000.

Conference Proceedings:

1. “Membrane Distortions in X-ray Masks due to Specific Absorber Features,” Emerging Lithographic Technologies, SPIE, Vol. 3048, pp. 146-154, (A. Fisher, R. Engelstad and M. Laudon), 1997.

2. “Stability and Stiffness Characteristics of the National X-ray Mask Standard,” Emerging Lithographic Technologies, SPIE, Vol. 3048, pp. 288-298, (A. Fisher, M. Sprague, R. Engelstad, D. Laird and S. Nash), 1997.

3. “Mask Requirements for Advanced Lithography,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 226-235, (W. Trybula and R. Engelstad), 1998.

4. “Transient Thermal Distortions of X-ray Mask Membranes During Exposure Scanning,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 261-274, (Z. Feng, R. Engelstad, E. Lovell and F. Cerrina), 1998.

5. “Photomask In-Plane Distortion Induced During E-Beam Patterning,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 275-279, (B. Shamoun, M. Sprague, R. Engelstad and F. Cerrina), 1998.

6. “Pattern Specific Emulation (PSE) for Ion-Beam Projection Lithography Masks using Finite Element Analysis,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 559-567, (A. Fisher, R. Engelstad and E. Lovell), 1998.

7. “Mechanical Distortions in Advanced Optical Reticles,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 601-611, (A. Mikkelson, M. Sprague, R. Engelstad, E. Lovell and D. Trost), 1998.

8. “Equivalent Modeling of SCALPEL Mask Membrane Distortions,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 612-620, (G. Dicks, R. Engelstad, E. Lovell and J. A. Liddle), 1998.

9. “Analysis, Design, and Optimization of Ion Beam Lithography Masks,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 621-628, (R. Tejeda, R. Engelstad, E. Lovell and I. Berry), 1998.

10. “Dynamic Characterization of Step-Induced Vibrations of X-ray Mask Membranes,” Emerging Lithographic Technologies II, SPIE, Vol. 3331, pp. 629-637, (M. Schlax, R. Engelstad and E. Lovell), 1998.

11. “Mask Blank Fabrication and Pattern Transfer for Electron-Beam Lithography (SCALPEL) Masks,” Proceedings of TECHCON ‘98, (G. Dicks, R. Engelstad, E. Lovell and J. A. Liddle), September 1998.

12. “Transient Analysis of the In-Plane Distortions of a SCALPEL Mask,” Proceedings of TECHCON ‘98, (W. Semke, R. Engelstad, E. Lovell and J. A. Liddle), September 1998.

13. “Predicting In-Plane Distortions due to Radiation Damage in X-ray Mask Membranes,” Proceedings of TECHCON ‘98, (E. Cotte, R. Engelstad and E. Lovell), September 1998.

14. “Mechanical Mounting Distortions in Advanced Optical Reticles,” Proceedings of TECHCON ‘98, (A. Mikkelson, R. Engelstad and E. Lovell), September 1998.

15. “Film Stack Stress Measurements for the SCALPEL Mask,” Proceedings of TECHCON ‘98, (M. Schlax, R. Engelstad, E. Lovell and J. A. Liddle), September 1998.

16. “Mechanical Distortions in Advanced Photomasks,” Proceedings of SPIE’s 18th Annual BACUS Symposium on Photomask Technology and Management, Vol. 3546, pp. 413-421, (A. Mikkelson, R. Engelstad and E. Lovell), 1998.

17. “Effects of Material Properties on Patterning Distortions of Optical Reticles,” Proceedings of SPIE’s 18th Annual BACUS Symposium on Photomask Technology and Management, Vol. 3546, pp. 214-220, (B. Shamoun, R. Engelstad, E. Lovell and W. Trybula), 1998.

18. “Finite Element Modeling of SCALPEL Masks,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 128-139, (R. Engelstad, E. Lovell, G. Dicks, C. Martin, M. Schlax, W. Semke, J. A. Liddle and A. Novembre), 1999.

19. “Modal Analysis of the SCALPEL Mask using Experimental and Numerical Methods,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 556-567, (W. Semke, M. Schlax, R. Engelstad, E. Lovell and J. Liddle), 1999.

20. “Stress Mapping Techniques for the SCALPEL Mask Membrane System,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 152-161, (M. Schlax, R. Engelstad, E. Lovell, J. Liddle and A. Novembre), 1999.

21. “Mechanical Distortions in Advanced Optical Reticles,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 744-755, (A. Mikkelson, R. Engelstad, E. Lovell, T. Bloomstein and M. Mason), 1999.

22. “Thermomechanical Distortions of Advanced Optical Reticles during Exposure,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 756-767, (J. Chang, A. Abdo, B. Kim, T. Bloomstein, R. Engelstad, E. Lovell, W. Beckman and J. Mitchell), 1999.

23. “Finite Element Modeling of Ion-Beam Lithography Masks for Pattern Transfer Distortions,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 768-778, (G. Frisque, R. Tejeda, E. Lovell and R. Engelstad), 1999.

24. “Thermomechanical Distortions of Ion-Beam Stencil Masks during Exposure,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 779-785, (P.-T. Lee, B. Kim, G. Frisque, R. Tejeda, R. Engelstad, E. Lovell, W. Beckman and J. Mitchell), 1999.

25. “Predicting Mechanical Distortions in X-ray Masks,” Emerging Lithographic Technologies III, SPIE, Vol. 3676, pp. 429-440, (E. Cotte, R. Engelstad, E. Lovell and C. Brooks), 1999.

26. “Modal Analysis of a Hybrid Grillage-Plate-Membrane Structure,” to appear in the Proceedings of the 18th International Modal Analysis Conference, (W. Semke, R. Engelstad and E. Lovell), 2000.

27. “Film Stress Changes during Anodic Bonding of NGL Masks,” to appear in Emerging Lithographic Technologies IV, SPIE, Vol. 3997, (E. Cotte, M. Schlax, R. Engelstad, E. Lovell and C. Brooks), 2000.

28. “Influence of Film Stress on Advanced Optical Reticle Distortions,” to appear in Emerging Lithographic Technologies IV, SPIE, Vol. 4000, (L. Siewert, A. Mikkelson, R. Engelstad, E. Lovell, M. Mason and R. Mackay), 2000.

29. “Comparison of Substrate Curvature and Resonant Frequency Thin Film Stress Mapping Techniques,” to appear in Emerging Lithographic Technologies IV, SPIE, Vol. 3997, (M. Schlax, R. Engelstad, E. Lovell and C. Brooks), 2000.

30. “Thermomechanical Modeling of the SCALPEL Mask during Exposure,” to appear in Emerging Lithographic Technologies IV, SPIE, Vol. 3997, (C. Martin, R. Engelstad, E. Lovell and J. Liddle), 2000.

31. “Pattern Transfer Distortions in IPL and EPL Mask with Pattern Density Gradients,” to appear in Emerging Lithographic Technologies IV, SPIE, Vol. 3997, (G. Frisque, R. Engelstad and E. Lovell), 2000.

32. “Thermomechanical Simulations for Microbeam Reduction Lithography,” to appear in Emerging Lithographic Technologies IV, SPIE, Vol. 3997, (G. Frisque, P.-T. Lee, R. Engelstad, E. Lovell, K. Leung and V. Ngo), 2000.

33. “Predicting Pattern Transfer Distortions during EUV Mask Fabrication,” to appear in Emerging Lithographic Technologies IV, SPIE, Vol. 3997, (P. Reu, R. Tejeda, R. Engelstad, E. Lovell and A. Ray-Chaudhuri), 2000