How fabs can improve throughput, yields, and cycle times

01/01/1999

How fabs can improve throughput, yields, and cycle times

After a few years of breathtaking growth, the semiconductor business actually declined in sales over the past year. Sharply lower average selling prices for DRAMs and many PC-related chips eroded revenues and slashed profits, even though unit shipments continued to grow. Worldwide fab construction almost ground to a halt, setting back the planned shift to 300-mm wafers and new tool sets. Instead, semiconductor producers are struggling to find ways to get more chips from their same facilities at much lower costs.

The challenge is being met. Shrinking circuit dimensions are allowing more chips to be made on the same size wafers. To maintain or even improve yields, better control of process parameters and contamination has been required. Automation and robotics are being improved, along with the software that helps keep wafers flowing steadily through the factory. Metrology is becoming much more critical, often moving from the laboratory right into processing equipment. Inventory modeling is being pushed to help suppress the costs of excessive work in progress. Interconnects are growing from four or five to six metal layers, and many more process steps must be integrated into the flow of wafers through the plant.

This Special Section probes the challenges associated with boosting productivity while improving yields and shortening cycle times. You`ll find a wide range of useful ideas and analytical approaches that can improve productivity, find and eliminate defects, and help manage production more skillfully.

If you have further ideas for improving semiconductor processing and managing fabs, we would like to hear from you. Send a proposal or an article to Editor, Solid State Technology, 98 Spit Brook Rd., Nashua, NH 03062-5737.

-Robert Haavind, Editor in Chief