To: Ian@SI who wrote (22683 ) 7/24/1999 11:47:00 AM From: Doug B. Read Replies (2) | Respond to of 25960
I had a tour of a fab for the first time yesterday. Boy, now I can see why these things have a multibillion dollar price tag! The fab was Dominion Semiconductor in Manassas, VA, about 20 mi. south of Washington, DC. It is a joint venture between IBM and Toshiba. They are producing 64Mb DRAMs and are ramping up to 256Mb DRAMs on a 0.17 micron process. The place was being built about 6 years ago, so they can only have been in production for a few years. They have tentative plans for another fab at the site which would support a 300mm process, but that is just in the planning stage. Not having seen one before, I didn't know precisely what I was looking at, but I did see a fair amount of AMAT equipment, and both Nikon and Cymer equipment. The fab is built on 3 floors - The basement has all the big pipes and flows of raw/spent materials. The ground floor contains all the chemical/gas/pressure/vacuum supply equipment which supplies materials to the process equipment. The top floor is the production floor. Class 1 cleanrooms with the user end of the process equipment alternate with class 10 rooms where the service end of the machines are found. Putting the production equipment on the top floor provides several benefits. Apparently the Japanese are quite adamant about not running ANY piping of any kind over the equipment, thus obviating the risk of damage due to a leak or pipe repair/replacement. Also, putting the procss equipment above the supply equipment reduces the weight of hardware on the process floor, allowing for a greater density of process equipment. One happy byproduct of this is that the photolithography room is the size of a football field with NO vertical supports since there is no floor above to support - just the roof. What else? Power from two separate grids. 24/7 operation (of course). Just trying to think what I saw. It's pretty neat to see first hand what you own a little piece of :) If anyone has any questions about what I saw, I will attempt to answer them. It's good to know what else to look for. Doug