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To: GuinnessGuy who wrote (7738)	11/1/1997 4:39:00 PM
From: D.J.Smyth	Respond to of 25960

Craig, you wrote <<Also, I called Intel's investor relations and tried to find out if their Texas fab pushout meant that they will not be purchasing as much semi-equipment as before. While the gentleman couldn't come up will a figure he stated that Intel now has plans to spend more on equipment for microprocessors than they had planned just a week or so ago. It was explained that the plant which they have just bought from DEC was under-capacitized and they will be buying tools for it. Also, I asked about migration to 0.25 micron and below and he practically fell off of his chair trying to convey to me the importance that Intel attaches to this right now! As a way of proof he talked about some recent "push-ins" of equipment in order to facilitate this migration. He wouldn't elaborate on the types of steppers that they will be employing though. Of course, I didn't expect that he would either.>> thank you much for this information. we know Intel has already been using SVGI Microscan III which is supported by Cymer. only Intel employees know more. now if only those short Cymer would pay attention to what you just wrote as it should be printed on the front page of wafer news. any connections?

To: GuinnessGuy who wrote (7738)	11/1/1997 10:37:00 PM
From: Maxwell	Read Replies (2) \| Respond to of 25960

Craig Siebels: <<Could you please clarify the part about the polishers(i.e - CMP)? I was under the impression from Mr. Sam(SpeedFam thread) that polishers were not in much use at 0.35 micron and above but became essential at ).25 micron. If my impression is/was wrong then I have certainly invested in SpeedFam for all of the wrongreasons:-(>> When Mr. Sam said that polishers were not much in use at 0.35um he meant the DRAM/SRAM makers. These devices use only 2 metal layer process and the metal lines and topography are not complex. Thus polish is not needed for these low profit margin product. Polishing is an expensive process. On the other hand, microprocessor chips of high performance usually consist of 3 or more level metal layers. The interconnects are long and the topography of these interconnects are extremely complex. Polish is used at every metal layer to planarize the surface to achieve high yields and high speed. Polishing has been used constantly in the industry to make microprocessors at 0.7um, 0.5um, 0.35um, 0.25um, and beyond. As the memory makers migrate to 0.25um and lower, the transistors are tighter packed and the metal lines are closer. Thus the topography is complex and gives problem to photolithography due to narrow depth of field in the 248nm wavlength. Polishing is almost a must to resolve the narrow depth of field to achieve high yield. You seem to concern about Intel's delay of the Texas fab. You must look at a bigger picture. A good number for the demand of DUV excimer steppers comes from VLSI's research. They project the demand for the DUV excimer steppers for 1998 be 700. I still think the actual number will be much higher as the industry is racing to get to the .25um and 300mm. Maxwell

To: GuinnessGuy who wrote (7738)	11/1/1997 11:18:00 PM
From: Maxwell	Read Replies (3) \| Respond to of 25960

DUV Excimer Laser, UV bulbs, Stepper, and Step/Scan Technology: I. Stepper: This is the tool that shoot a whole field image and step to the next field. ----Advantages: -----1) It's faster than the scan and step tool -----2) Field to field exposure is more uniform ----Disadvantages: -----1) Uses expensive lens system (cost over $1M) -----2) Excimer laser can densify the quartz and change its --------characteristics. -----3) Limited number of systems can be manufactured due to limited --------number of companies that can grind the lenses to high --------precision. -----4) Possibility of worse spherical abberation compared to the scan II. Scan/Step: A small portion of the lens is used to focus and a small part of the field is exposed. The beam is scanned across the entire field. The stage then move the wafer to the next field and the process is repeated. -----Adavantages: -----1) Mirrors are used heavily to focus the beam. Mirrors don't --------get densified by the excimer laser. Thus doesn't have to --------change the lens out often. -----2) Cheaper because less lenses are used. Lenses are more --------expensive than mirror. -----3) Better spherical aberration (for focusing) -----4) More systems can be built because mirrors are easy to produce -----Disadvantages: -----1) Slower throughput. -----2) Possible stitching across the field III. UV bulbs: DUV wavelength source for the stepper or scanners. -----Advantages: -----1) Cheap -----Disadvantages: -----1) Intensity is not constant and decreases as approaching bulb --------life. Thus inconsistent exposure dosage. -----2) Spectrum is broad even with filter. This will lead to --------focusing problem due to spherical arberration and variation --------in same feature size across the field. IV. Excimer Laser: -----Advantages: -----1) Monochromatic. Consistent dosage from field to field. -----2) No drift in wavelength and dosage as the life of the laser --------approaches its PM frequency. -----3) Higher throughput -----Disadvantages: -----1) It is expensive. -----2) It densify the lenses. So much for the background. What leading fabs who have used DUV excimer laser steppers and scanners throughout the industry found out is that the yield is higher, the throughput is increased, and the speed is running at higher speed compared to same chips that were manufactured using DUV bulbs. Higher speed and higher yield has to do with variations in the polygate CDs. The tigher the distribution of the poly CDs the better the chip performs since all transistors are running at same frequency. The tighter the distribution the easier it is to drop the gate width to get higher speed without going beyond the designed gate width. If you go beyond the designed gate width then the transistor will be leaky and will not switch. Had the distribution of the gate width been large from using the UV bulbs it will be impossible to drop the gate width further without getting some transistors with gate widhts beyond the forbidden region. Due to this result CPU companies such as Intel, IBM, AMD,TXN, etc. will use DUV excimer laser to make fast microprocessors. DRAM/SRAM makers will use DUV excimer laser to achieve higher throughput. lower cost of ownership, and higher yield. ASM will introduce the scan and step tool soon. The reason they resort to this technique is that ZEISS can only supply a limited number of lenses and the demand for the steppers is much greater than ZEISS can satisfy. Maxwell