COMPARISON OF SUBMICRON PARTICLE ANALYSIS BY AUGER-ELECTRON SPECTROSCOPY, TIME-OF-FLIGHT SECONDARY-ION MASS-SPECTROMETRY, AND SECONDARY-ELECTRON MICROSCOPY WITH ENERGY-DISPERSIVE X-RAY SPECTROSCOPY

Particulate contamination can result in a significant yield loss durin g semiconductor device fabrication. As device design rule dimensions d ecrease the critical defect size also decreases, resulting in the need to analyze smaller defects. Current manufacturing requirements includ e analysis of sub-0.5-mu m defects, with analysis of sub-0.1-mu m defe cts expected in the near future. This article investigates the particl e analysis capabilities of Auger electron spectroscopy, time-of-flight secondary ion mass spectrometry, and energy dispersive x-ray spectros copy during scanning electron microscopy (SEM/EDS). In order to evalua te each method carefully, a standard set of samples was prepared and a nalyzed. These samples consist of 0.5-, 0.3-, and 0.1-mu m Al and Al2O 3 deposited on 1-in. Si wafers. Although all the methods observed an A l signal, a semiquantitative gauge of capability based on the relative strengths of particle versus substrate signal is provided. The depend ence of the sample-to-substrate signal on primary electron energy is e xamined for both EDS and Auger analyses. The ability to distinguish me tallic Al particles from Al oxide particles for the three techniques i s also discussed. (C) 1996 American Vacuum Society.