HVAC Control in the New Millennium.pdf - HVAC.Amickracing

PC-based Control, Software and Bus Trendswould be able to handle 100 billion operations per second.In the future, doubling the transistor count may require more than18 months, due to major changes in chip design or fabrication technology.Chip logic is becoming more complex and requires longer designand validation times.Fabrication TechnologyFabrication technology must improve with each process generation,such as the change from 0.25-microns to 0.18. A critical part of theprocess is photolithography, where short-wavelength light sources arefocused with precision lenses through the transparent masks containingthe circuit details. This exposes the photoresist on a wafer’s surface,which is chemically removed leaving the details of the circuit pattern onthe wafer.Light sources and optics must evolve together. Intel’s 0.18-micronPentium III chips use the same 248-mm wavelength deep-UV lightsource as 0.25-micron Pentium II and Pentium III chips. The move to a0.13-micron process should be coupled with 193-nm wavelength lightfrom excimer laser sources.Beyond 0.13-microns would be a 0.09-micron process, whichwould use 157-nm wavelength excimer lasers. The next step below 0.09is major in terms of technology and manufacturing processes. Thiswould be the 0.07-micron process for the 2011 processor.The level of photolithography will probably require extreme-UV(EUV) light sources. EUV has a wavelength of 13nm, which has thepotential for etching much smaller transistors. The problem is that thereare no known transparent mask materials that will allow these shortwavelengths to pass through. New reflective lithography processes andoptics would need to be implemented.As the number of transistors increases on a chip, transistor interconnectwires become smaller and closer together. This increases conductorresistance and capacitance which adds to any signal delays.To reduce resistance and shrink the interconnect line widths, coppercan be used to replace aluminum as the interconnecting metal. Copperis being used in IBM’s Power G3 chips and AMD’s newer ships. Inthe future Intel CPUs in the 0.13-micron class should use copper interconnects.©2001 by The Fairmont Press, Inc. All rights reserved.