| US 7,514,681 B1 | ||
| Electrical process monitoring using mirror-mode electron microscopy | ||
| Paul F. Marella, San Jose, Calif. (US); Mark A. McCord, Los Gatos, Calif. (US); Marian Mankos, Palo Alto, Calif. (US); and David L. Adler, San Jose, Calif. (US) | ||
| Assigned to KLA-Tencor Technologies Corporation, Milpitas, Calif. (US) | ||
| Filed on Jun. 13, 2006, as Appl. No. 11/451,698. | ||
| Int. Cl. H01L 21/02 (2006.01); H01J 37/145 (2006.01); G21K 7/00 (2006.01) | ||
| U.S. Cl. 250—310 [250/306; 250/307; 250/370.08; 250/492.1; 324/501; 324/750; 324/751; 324/765] | 32 Claims |
| 1. A method of inspecting a substrate using electrons, the method comprising:
obtaining multiple images of a region of the substrate using mirror-mode electron-beam imaging at a range of voltage differences
between an electron source and a substrate, each said image corresponding to one said voltage difference;
storing image data corresponding to the multiple voltage differences; and
calculating a measure of variation of an imaged aspect of a feature in the region with respect to the voltage difference between
the electron source and the substrate,
wherein the method provides sub-volt voltage contrast between said images without needing to use an energy-filter with sub-volt
resolution.
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