| 摘要 |
An ultranarrow insulated trench isolation structure is formed in a semiconductor substrate without creating voids in the insulating material which adversely affect the performance of finished devices. Embodiments include forming a narrow trench in the semiconductor substrate, then forming a spacer on the sidewalls of the trench, as by depositing and anisotropically etching a layer of silicon dioxide, amorphous silicon, or silicon oxynitride. The trench is then refilled as by conventional LPCVD, PECVD or HDP techniques, and the spacers are oxidized, if necessary. Since the spacers, in effect, create sloped trench walls, the trench fill can be performed, even at a high deposition rate, with substantially fewer voids than conventional processes, while also reducing reentrance of the trench walls.
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