Method for forming storage node of capacitor in semiconductor device

A method for forming a capacitor in a semiconductor device, the method comprising:

• sequentially forming a first insulation layer and a second insulation layer each with a different etch characteristic over a substrate;
• forming a plurality of first contact holes extending through the first and the second insulation layers;
• forming spacers with the same etch characteristic as the second insulation layer on sidewalls of the first contact holes;
• forming a plurality of storage-node contact plugs filled into the first contact holes;
• forming an etch stop layer having the same etch characteristic as that of the second insulation layer over the storage-node contact plugs;
• forming a sacrificial oxide layer over the etch stop layer;
• sequentially etching the sacrificial oxide layer and the etch stop layer to form a plurality of second contact holes exposing the storage-node contact plugs;
• and
• forming the storage node on each of the second contact holes.

A method for forming a capacitor in a semiconductor device, the method comprising:

• forming a first insulation layer over a substrate;
• forming a plurality of first contact holes extending through the first insulation layer;
• forming spacers having a different etch characteristic from that of the first insulation layer on sidewalls of the first contact holes;
• forming a plurality of storage-node contact plugs filled into the first contact holes;
• forming an etch stop layer having the same etch characteristic as an etch rate that of the spacers over the storage-node contact plugs;
• forming a sacrificial oxide layer over the etch stop layer;
• sequentially etching the sacrificial oxide layer and the etch stop layer under an etch recipe of oxide etching, thereby forming a plurality of second contact holes exposing the storage-node contact holes;
• and
• forming the storage-node on each of the second contact holes.

A method for forming a capacitor in a semiconductor device, the method comprising:

• forming a first insulation layer over a substrate;
• forming a plurality of first contact holes extending through the first insulation layer;
• forming spacers with a different etch characteristic from that of the first insulation layer on sidewalls of the first contact holes;
• forming a plurality of storage-node contact plugs such that the storage-node contact plugs are filled into the first contact holes, wherein the height of the storage-node contact plugs is higher than the height of the first insulation layer;
• forming a second insulation layer with the same etch characteristic as that of the first insulation layer over the storage-node contact plugs;
• planarizing the second insulation layer at the same level of the storage-node contact plugs;
• forming an etch stop layer with the same etch characteristic as that of the spacers over the storage-node contact plugs;
• forming a sacrificial oxide layer over the etch stop layer;
• performing an etching process that provides a low etch selectivity of the spacers with respect to the storage-node contact plugs to form a plurality of second contact holes exposing the storage-node contact plugs;
• and
• forming the storage node on each of the second contact holes.

A method for forming a capacitor in a semiconductor device, the method comprising:

• forming an inter-layer insulation layer over a substrate;
• etching the inter-layer insulation layer to form a plurality of first contact holes;
• forming spacers on sidewalls of the first contact holes;
• filling storage-node contact plugs into the first contact holes;
• forming an etch stop layer over the storage-node contact plugs;
• forming an insulation layer over the etch stop layer;
• etching the insulation layer and the etch stop layer to form a plurality of second contact holes exposing the storage-node contact plugs;
• selectively recessing predetermined portions of the inter-layer insulation layer exposed through the second contact holes by using a different etch selectivity between the inter-layer insulation layer and the spacers;
• and
• forming the storage node on each of the second contact holes.