Membrane contractors are widely used in the semiconductor industry to control the dissolved gas levels in high purity water. They have been commercially available for almost 10 years and the technology has rapidly advanced to meet the demanding needs of the semiconductor industry. The industry is in the midst of moving to 300-millimeter (mm) wafer sizes, while at the same time decreasing the line widths of the integrated circuits. This article discusses the changing specifications and offers the reader advice on how to meet the dissolved oxygen specifications using membrane contactors.
The semiconductor industry is now in the middle of two major transitions. The first is a shift from 200- to 300-mm wafer diameters. The driving force behind this shift is a cost-reduction effort. The cost savings will come from higher volumes of chips per unit wafer as well as expected yield improvements. A 300-mm wafer has 2.25 times the surface area of a 200-mm wafer. This means that 2.25 times the number of chips can be produced on a300-mm line as compared to a 200-mm line. Studies at laiwan Semiconductor Manufacturing Company (TSMC) have found that when comparing 200- and 300-mm wafers, the numbers of particles per wafer were unrelated to the wafer size. This indicates that the number of defects per wafer caused by particles was the same for 200- and