E-Beam Lithography System (Raith EBPG 5150+)
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About
TBD
Detailed Specifications
- Maximum write area:
- Maximum wafer/substrate size:
- Cassette loader/substrate holders available
- Beam Voltage: 100kV
- Min/Maximum Current (Dose):
- Scanner Speed (or other speed specs):
- Layer-to-Layer Alignment Accuracy:
- Options purchased:
- Non-Manhattan scanning for curved edges
- Stand-alone optical alignment station
- OTHER
(Other EBL-specific specs)
- Advanced Fracturing software available (Layout BEAMER from GeniSys, Inc)
- automated proximity correction of patterns possible
- ability to manually position write fields within a pattern for optimum inter-field writing performance
- ability to adjust beam scanning strategy within a write field for optimum intra-field writing performance
- fine tuning of line-edge roughness by shot pitch correction
Electron Beam Resists
EBL Resists are custom-mixed according to user resolution needs - contact Bill Mitchell.
Currently available at UCSB are:
- PMMA: (950K in anisole, 950K in MIBK, 495K in anisole, 50K in anisole): very high-resolution positive polymer-based resist with relatively poor sensitivity (resolution scales directly and sensitivity scales inversely with molecular weight); very poor plasma etch resistance, hence used primarily to fabricate metal lines via liftoff processes (via a bi-layer resist scheme...low MW on bottom, high MW on top for single lines, or vice-versa for T-gate fabrication); utilizes an inert solvent developer (usually MIBK:IPA mixtures)
- P(MMA-MAA) copolymer: (low MW methyl-methacrylate (MMA) and methacrylic acid (MAA) copolymers in ethyl lactate): a positive polymer-based resist with poor resolution but with significantly higher sensitivity than the higher MW PMMA resists above; used primarily as the top layer in a bi-layer resist scheme for T-Gate fabrication, and utilizes inert solvent developer (MIBK:IPA mixtures)
- CSAR-62: ZEP-equivalent resist manufactured in Germany at much more competitive pricing!; very high-resolution polymer-based positive resist with very good sensitivity and excellent etch resistance; can be used in both metal lift-off processes (slight overexposure results in an excellent undercut profile) and various dry-etch processes for pattern transfer to the underlying substrate; utilizes inert solvent developers (e.g., n-amyl acetate for higher sensitivity and good resolution or MIBK:IPA mixtures for increased LER performance)
- maN-2403: negative polymer-based resist (that is NOT chemically amplified) with very good resolution (down to the 40-50nm range) and sensitivity; exhibits excellent dry-etch resistance; developed using a dilute basic solution (e.g., metal-ion-free developers such as AZ-300MIF)
- HSQ: negative resist that is based on spin-on glass material (ie, not polymer-based) with extremely good resolution (features below 10nm can be resolved); etch resistance is high in Cl-based chemistries since HSQ reduces to a porous SiOx structure after exposure and development; sensitivity and contrast are very dependent on developer solution used and are usually poor - standard AZ300MIF developer solutions have decent sensitivity (100's of uC/cm2 at 100kV) but extremely poor contrast, stronger (and toxic!) 25%TMAH solutions have much better contrast but poor sensitivity (1000's of uC/cm2 at 100kV), "salty" developer solutions using 1wt% NaCl dissolved in either 4wt% NaOH or AZ300MIF solutions have the best contrast but reduce sensitivity significantly (10,000's of uC/cm2 at 100kV)
- UV6/UVN-210: chemically amplified polymer-based resists with high resolution and excellent sensitivity (clearing doses below 100uC/cm2 at 100kV); UV6 used mostly in optimized t-gate resist structures; developed using a dilute basic solution (e.g., metal-ion-free developers such as AZ-300MIF)