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US 6,207,579 B1Granted
Method of fabricating self-aligned node
AssigneeUnited Micoelectronics Corp.
InventorTerry Chung-Yi Chen
Life of this patent
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Abstract
A method of fabricating a self-aligned storage node is described. A storage node plug is formed after formations of the bit line contact and the storage node contact. A spacer is formed on a sidewall of an opening, which is used for forming a bit line. The bit line is formed in the opening. Because the spacer provides good isolation, the tolerance window for forming the bit line is increased. Some follow-up steps are performed to form a storage node.
Claims20
A method of fabricating a self-aligned storage node, comprising steps of:
- forming a first insulating layer on a substrate;
- forming a preserve layer on the first insulating layer;
- forming a bit line contact and a storage node contact in the preserve layer and the first insulating layer, wherein the bit line contact and the storage node contact are in contact with a source/drain region in the substrate;
- forming a second insulating layer on the bit line contact, the storage node contact, and the preserve layer;
- forming a storage node plug and a cap layer in a second insulating layer, wherein the cap layer is formed on the storage node plug, and the storage node plug connects to the storage node contact;
- patterning the second insulating layer to form a first opening that exposes the bit line contact;
- forming a spacer on a sidewall of the first opening;
- forming a bit line in the opening to make contact with the bit line contact;
- forming a third insulating layer to cover the second insulating layer and the bit line;
- and
- patterning the third insulating layer, the cap layer, and the second insulating layer to form a second opening exposing the storage node contact;
- and
- forming a first conductive layer in the second opening.
10 more elements
A method of fabricating a bit line, comprising steps of:
- forming a first insulating layer on a substrate;
- forming a preserve layer on the first insulating layer;
- forming a bit line contact and a storage node contact only in the preserve layer and the first insulating layer, wherein the bit line contact and the storage node contact are in contact with source/drain region in the substrate;
- forming a second insulating layer to cover the bit line contact, the storage node contact, and the preserve layer;
- forming a storage plug in the second insulating layer, wherein a cap layer is formed on the storage node plug, and the storage plug connects to the storage node contact;
- patterning the second insulating layer to form a first opening that exposes the bit line contact, wherein the cap layer protects the storage node plug from being etched;
- forming a spacer on a sidewall of the first opening;
- and
- forming the bit line in the opening to make contact with bit line contact, wherein the spacer provides an isolation function in between the bit line and the storage node plug.
6 more elements
Dependencies are inferred from the claim text.