| US 7,465,644 B1 | ||
| Isolation region bird's beak suppression | ||
| Simon S. Chan, Saratoga, Calif. (US); Weidong Qian, Sunnyvale, Calif. (US); Scott Bell, San Jose, Calif. (US); Phillip Jones, Fremont, Calif. (US); and Allison Holbrook, San Jose, Calif. (US) | ||
| Assigned to Advanced Micro Devices, Inc., Sunnyvale, Calif. (US); and Spansion LLC, Sunnyvale, Calif. (US) | ||
| Filed on Oct. 26, 2005, as Appl. No. 11/258,209. | ||
| Int. Cl. H01L 21/76 (2006.01) | ||
| U.S. Cl. 438—439 [438/424; 257/E21.546] | 24 Claims |
| 1. A method, comprising:
forming a first layer of oxide over a semiconducting layer;
forming a layer of nitride over the first layer;
forming a second layer of oxide over the nitride layer;
forming a layer of Al2O3, HfO2 or Ta2O5 over the second layer of oxide;
etching a pattern in the layer of Al2O3, HfO2 or Ta2O5 to expose portions of the semiconducting layer; and
oxidizing at least one of the exposed portions of the semiconducting layer, using an oxidation process, to form an electrical
isolation region, where the oxidation process directly oxidizes the at least one of the exposed portions of the semiconducting
layer without oxidizing through any other intervening layers.
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