Nice article on Lithography.
e-insite.net;
-- Thanks....
At this point, there are only about 10 machines worldwide using 193 nm lithography in a production environment, according to Peter Silverman, an Intel fellow and director of lithography capital equipment development at Intel Corp. (Santa Clara, Calif.).
-- So, CED is intel's Manufacturing Tool Purchase Department. This seems to verify what I've heard about 193nm being in very limited availability:
"At this point, it doesn't look like [157 nm lithography] will be ready in time, so we'll start off with 193, then switch to 157 when it becomes available," Silverman said. The same is true for EUV, at which point Intel will rely instead on 157 nm tools.
-- Most likely the issues with the more advanced steppers down the road will be Lens Optical Quality issues.... and footprint. Those suckers are getting real big.....
"The cornerstone to this extension capability is engineering the wavefront by providing mask-based solutions." Granted, the more complex masks come at a cost, but maskmakers have been working to minimize those increases, Carlson said. "Of course the enormous increase in complexity of the mask adds additional cost, but balanced against the value being delivered now by the mask, instead of the traditional areas of new projection systems, resist, etc., mask value vs. cost actually shows a much more stable trend. At some point it becomes a game of trade-offs."
-- Anybody still wondering why AMD hooked up with Dupont on PhotoMasks?? Me neither.
:-)
Developing soft pellicles for 157 nm photomasks has been difficult because progress has been slow on the development of polymers that maintain their transparency while being irradiated at 157 nm. According to reports at the third 157 nm technical data review, held last month by International SEMATECH (ISMT), ISMT has launched a project involving several universities to study the mechanisms of photochemical darkening. This should ultimately lead to the development of polymer materials that can withstand 157 nm radiation
-- If I recall my Litho (it's been 4 years), the pellicle was the material that the chrome lines of the photomask were adhered to. the chrome blocked the light, casting a shadow on the wafer's photoresist, and the clear parts of the pellicle would transmit the light to the resist. But I remember quartz pellicles, not soft ones....
Meanwhile, progress is also being made on hard pellicles, which may present an interim solution. Hard pellicles use modified fused silica sheets of ~800 µm that provide ~95% transmission at 157 nm.
-- There we go......... I guess I shouldn't be posting in parallel with reading eh?
"EUV isn't a slam dunk," Silverman admitted. Intel has been a major proponent of the EUV effort, spearheading the EUV LLC, a consortium of chipmakers that also includes AMD, Motorola, Micron Technology, Infineon and, just recently, IBM. Intel recently ordered an EUV lithography beta tool from ASML (Veldhoven, Netherlands), slated for delivery in late 2005.
-- It's that Optical Lens thingy......
Gwyn agrees that the source is the most challenging hurdle facing EUV lithography because of the target of 80 wph throughput. "At present, the LPP source is the most promising source because the most work has been done on this source to understand problems and resolve scale-up issues," he said. "If a compact illuminator design can be made to multiplex sources, many of the discharge sources have good potential because of the lower cost and better conversion efficiencies of electrical energy to EUV flux."
--- Blah Blah Blah Blah Blah....... Why can't they just say their lamp's not giving off enough light......
Though certainly not to the degree of 157 nm and EUV lithography, e-beam lithography is the only other NGL candidate being given any degree of serious consideration at this point. E-beam has been a contender for more than 20 years, Ware noted, and is still not where it needs to be.
-- I hear the footprint is too big, where fab space is at a premium, and the throughput is too slow, which is a fatal flaw.
No matter what the technology, decisions about what technique to pursue at any given time come down primarily to economic drivers. This economic issue is a given as tool complexity continues to grow with each new generation, ASML's Cossins said, noting extreme contamination requirements for 157 and EUV, as well as complex metrology and software requirements.
-- WAG translation..... Steppers are already enclosed in laminar flow enclosures, but the "contamination" statement seems to suggest "Sealed" Sysytems. Metrology is the Analytical Equipment for checking Stepper Performance. Complex Software could mean anything.
Conclusion: Lithogpraphy drives manufacturing, and it seems that Litho Equipment is going to get Longer Lead times, Larger Sizes, and MUCH Greater Expense..... as soon as everyone can figure out what the heck they want....
Semi |
