Method of forming interconnects
AssigneeNanya Technology Corporation
InventorsTse-Yao Huang, Chih-Ching Lin, Yu-Chi Sun, Chang Rong Wu, Shing-Yih Shih
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Abstract
A method of forming interconnects. An oxide masking layer with patterns is formed overlaying the metal layer. The patterns of the masking layer are transferred into the metal layer so as to form an opening. Then, a silicon nitride liner is conformally formed on the masking layer, the metal layer and the first insulating layer. Next, the silicon nitride liner and the masking layer are partially removed by reactive ion etching to leave a facet mask to reduce the aspect ratio of the opening followed by removal of the remaining silicon nitride liner. Then, an insulating layer is deposited to fill the opening.
Claims17
A method of forming interconnects, suitable for a semiconductor substrate with a first insulating layer thereon, comprising the steps of:
- providing a metal layer on the first insulating layer;
- forming a masking layer with patterns overlaying the metal layer;
- transferring the patterns of the masking layer into the metal layer so as to form an opening;
- conformally forming a silicon nitride liner on the surfaces of the masking layer, the metal layer and the first insulating layer;
- partially removing the silicon nitride liner and the masking layer by reactive ion etching to leave a facet mask with high etch selectivity of the silicon nitride liner at the corner with respect to the bottom to reduce the aspect ratio of the opening;
- removing the silicon nitride liner;
- and
- forming a second insulating layer to fill the opening.
A method of forming interconnects, suitable for a semiconductor substrate with a first silicon oxide layer thereon, comprising the steps of:
- providing a metal layer on the first silicon oxide layer;
- forming a silicon oxide masking layer with patterns overlaying the metal layer;
- transferring the patterns of the silicon oxide masking layer into the metal layer so as to form an opening;
- conformally forming a silicon nitride liner on the surfaces of the silicon oxide masking layer, the metal layer and the first silicon oxide layer;
- partially removing the silicon nitride liner and the masking layer by reactive ion etching to leave a facet mask, wherein the silicon nitride liner at the corner has an etch selectivity of 10 to 20 with respect to the silicon oxide masking layer, and the silicon nitride liner at the bottom has an etch selectivity of 50 with respect to the first silicon oxide layer to reduce the aspect ratio of the opening;
- removing the silicon nitride liner;
- and
- forming a second silicon oxide layer to fill the opening.
A method of forming interconnects, suitable for a semiconductor substrate with a first insulating layer thereon, comprising the steps of:
- providing a metal layer on the first insulating layer;
- forming a masking layer with patterns overlaying the metal layer;
- transferring the patterns of the masking layer into the metal layer so as to form an opening;
- conformally forming a silicon nitride liner on the surfaces of the masking layer, the metal layer and the first insulating layer;
- partially removing the silicon nitride liner and the masking layer by reactive ion etching to leave a facet mask with high etch selectivity of the silicon nitride liner at the corner with respect to the bottom to reduce the aspect ratio of the opening;
- removing the remaining silicon nitride liner in the opening to expose sidewalls of the metal layer and the surface of the first insulating layer;
- and
- forming a second insulating layer to cover the metal layer and the first insulating layer and fill the opening.
Dependencies are inferred from the claim text.