Detection and Measurement of Particulate Contaminants

Abstract Detection and classification of defects generated during the integrated circuit fabrication steps are of critical importance to both attaining and maintaining a high-yielding manufacturing process, which will enable the production of superior devices. Nondestructive, high-speed techniques and instrumentation that enable both the detection and classification of features down to 19 nm in size on 300-mm wafers are outlined in this section. As such inspection instrumentation matured over the past 20+ years, it is now possible to investigate the front and back surfaces of the wafers plus areas related to its edge. Correlation of such small-sized defects of interest to yield-limiting performance has also gained more traction with circuit manufacturers, thus helping to better define optimal process windows. As technology nodes have advanced, there has been an increased focus on monitoring the particle levels to which the wafer is exposed in ultrapure water, in process and cleaning chemicals, and the wafer environment inside of equipment front end modules. The state of the art now allows for particles as small as 20 nm (10 nm for certain metallic particles) to be monitored in ultrapure water and chemicals and 10 nm in air and inert gases. This monitoring capability allows for more refined and advanced process control strategies to be developed.