To: Cary Chubin who wrote (15030 ) 2/25/1998 3:34:00 PM From: Andrew Vance Read Replies (5) | Respond to
Heavens No Sir!!!Flashlight Lithography - broadband UV light used to image features. this included the g,h,i line wavelengths of light (436,405,365nm wavelengths of light) used in contact printers and projection aligners. This was used from greater than 10u feature sizes down to, let's just say 2.0u feature sizes. Arguments can be made for the lower limit but let's just use that number for illustrative purposes. This technology took us from the early contact printers where the mask and the wafer were either in contact or close proximity to each other up through the projection aligners that stuck a great deal of optics between the mask and the wafer.UV Lithography - tighter band UV light used or pass band filters used to image device features. Some of this appeared on the projection aligners but mostly were introduced with the wafer steppers. This techology used gh, g, and i-line wavelengths of light (436/406, 436, 365nm) to accomplish the task and utilized reticles instead of masks. Masks had repititive images on them since the entire mask image was scanned across the wafer. Steppers had discrete fields of limited images that were stepped across the wafer. This technology was implemented at 2.0u(1.0u to 2.0u) and was successfully used down to 0.35u feature sizes. Again a debate can be made for 0.25u but it is irrelevant to the discussion.DUV Lithography . Many discussions and debates have occurred over the last few years as to when DUV would run out of gas. no one really believed it could enjoy a life cycle like the above two technologies. It was thought to be an interim lithographic process of limited life before you were forced to use e-beam or x-ray which both have major production hurdles to overcome. As it turns out, the existing 193nm laser has been used to get features down to 0.08u which translates to about 5 device possible technologies (0.25u 0.18u, 0.13/.015u, 0.11/0.10u, and 0.08u) without even needing a new wavelength laser. Of course we know that CYMI is working on some advanced lasers. we can conclude that given the advances in DUV laser technology, 0.08u will be a given once it is needed for production. this recent breakthrough might even expedite the move to sub 0.10u device features.
