| 摘要 |
A method for fabricating high-aspect-ratio contacts on integrated circuits, such as embedded DRAMs, using a borderless pre-opened hard-mask technique is achieved. After forming gate electrodes for field effect transistors (FETs) and local interconnections from a polycide layer having a silicon nitride (Si3N4) hard mask or cap layer, an anti-reflective coating is used to protect the FET source/drain areas. A photoresist mask and plasma etching are used to remove portions of the hard mask on the interconnections for contact openings, while the anti-reflective protects the source/drain areas. The photoresist mask and the anti-reflective coating are removed, and an interlevel dielectric (ILD) layer is deposited. The high-aspect-ratio contact openings can now be etched in the ILD layer to the source/drain areas, while concurrently etching reliable contact openings to the polycide interconnections where the cap Si3N4 has been removed without overetching the source/drain areas.
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