Electron-beam lithography
Michael Rooks
Malone Engineering Center, room 003B
About the instruments
For nanoscale patterning, the Raith EBPG 5000+ and EBPG 5200+ electron-beam lithography systems provide 100 kV patterning of 10 nm-scale devices. These electron-beam writers are fully automated, with a laser-guided substrate stage providing 15 nm field stitching, 15 nm overlay accuracy, laser height measurement for automatic focus adjustment, and metrology functions for self-calibration. The EBPG is highly regarded for its ease of use and very flexible control software. Yale programs utilizing electron beam lithography include research in optical waveguides, quantum computing, electron transport physics, and photonic bandgap engineering.
Available to Yale researchers & external researchers
Specifications
| EBPG 5000+ | EBPG 5200+ | |
|---|---|---|
| Accel. voltage | 100 kV | 100 kV |
| Beam current | 0.5 to 150 nA | 0.5 to 350 nA |
| Min spot size | 4 nm | 4 nm |
| Min line width | 10 nm | 10 nm |
| Max clock | 50 MHz | 125 MHz |
| Substrate size | 1 to 15 cm (6 inch) | 1 to 20 cm (8 inch) |
| Detectors | scintillator backscatter | scintillator backscatter and biased secondary ET detector |
| Loader | 10 holder | 10 holder |
| Max field | 1 mm | 1 mm |
Rates
Rates in US$/hour unless otherwise noted
| Yale academic | External academic | Industrial | |
|---|---|---|---|
| SEM, Hitachi | 37 | 61 | 215 |
| AFM, Bruker | 35 | 58 | 105 |
| e-beam, EBPG | 100 | 165 | 300 |
| TEM, FEI Osiris | 100 | 165 | 300 |
| Ion mill, Fischione | 37 | 61 | 111 |
| Ion mill, Hitachi | 37 | 61 | 111 |
| Gold sputtering | 20 | 32 | 76 |
| Iridium sputtering | 20 | 32 | 76 |
| Microtome, Leica | 30 | 50 | 90 |
| HSQ resist, 4 ml | 25 ea | 41 ea | 75 ea |
| CSAR resist, 4 ml | 20 ea | 33 ea | 60 ea |
| Dektak profilometer | 10 | 16 | 45 |
Training & services
EBPG training is now an online Yale Canvas course, which covers machine hardware, CAD, data preparation, and job setup. Please contact the YINQE staff for an invitation to enroll. After you complete the course, you will do hands-on training with the EBPG e-beam system, using a video-based course similar to the ones used for SEM and TEM.
In case you would like to see the course material without enrolling, here are the presentations. Feel free to plagiarize with impunity. No permissions or citations are required.
Getting the least from your e-beam
Beamer 4.2.0 tutorial (used on the ebpg-5000)
Beamer 6.1.1 tutorial (used on the ebpg-5200)
E-beam prep tools
Bruker Dektak XT stylus profilometer
The Bruker Dektak profilometer measures step heights, surface profiles and roughness using a stylus with a 12.5um radius tip. Step heights can range from ~5 nm to 1 mm, with scan lengths up to 55mm. The stylus force is usually set to 10mg, but can be set below 1mg for soft materials. 3D imaging (using 2D scans) can be done, although this is rather slow compared to an optical profilometer.
Cressington 208 iridium sputtering tool
Iridium is useful for coating samples before electron microscopy. The Cressington 208 iridium sputtering tool provides very smooth, conformal coatings which are free of the grain structure found in films of Au or Au-Pd. Chromium would also be a good choice for coating SEM samples, but iridium oxidizes much more slowly, and so has an advantage over fine-grained chromium films.
A sputter coater for gold is located next to the chromium system. Gold is used for coating electron-beam resist before lithography, but is not a good choice for SEM samples.
Links
Caltech EBPG (Note that some procedures described here are not allowed at Yale. Be sure to ask permission before trying anything new.)
Storing HSQ in liquid nitrogen
HSQ essential tips from the FAQ files
Development of PMMA in IPA/water