Method of forming a metal to polysilicon contact in oxygen environment
AssigneeMicron Technology, Inc.
InventorWerner Juengling
Life of this patent
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Abstract
A method for forming a contact capable of tolerating an O2 environment up to several hundred degrees Celsius for several hours is disclosed. To slow down the metal oxide front of the metal layer at the metal-polysilicon interface, the metal layer is surrounded by one or more oxygen sink spacers and layers. These oxygen sink spacers and layers are oxidized before the metal layer at the bottom of the plug is oxidized. Accordingly, the conductive connection between the polysilicon and any device built on top of the barrier layer is preserved.
Claims26
A method for forming a metal-polysilicon contact in a semiconductor device, comprising the acts of:
- forming an insulating layer over a barrier layer residing over a polysilicon layer;
- forming a contact opening in said insulating layer;
- forming at least one conductive layer and at least one oxygen sink layer in said contact opening, said oxygen sink layer being capable of absorbing oxygen;
- and
- forming a semiconductor device over said at least one oxygen sink layer and said conductive layer.
A method for forming a metal-polysilicon contact in a semiconductor device, comprising the acts of:
- forming an insulating layer over a barrier layer residing over a polysilicon layer;
- forming a contact opening in said insulating layer;
- forming at least one conductive layer and at least one oxygen sink layer in said contact opening, said oxygen sink layer being capable of absorbing oxygen and being formed as a plurality of spaced oxygen sink layers;
- and
- forming a semiconductor device over said at least one oxygen sink layer and said conductive layer.
A method for fabricating a metal-polysilicon contact in a semiconductor device, comprising the acts of:
- forming an insulating layer over a barrier layer residing over a polysilicon layer;
- forming a contact opening in said insulating layer;
- forming at least one conductive layer and at least one oxygen sink layer in said contact opening, said oxygen sink layer being capable of absorbing oxygen;
- forming a capacitive element over and in contact with said conductive layer;
- and
- subjecting said capacitive element to a nitrogen/oxygen anneal treatment.
A method for fabricating a metal-polysilicon contact in a semiconductor device, comprising the acts of:
- forming an insulating layer over a barrier layer residing over a polysilicon layer;
- forming a contact opening in said insulating layer;
- forming at least one conductive layer and at least one oxygen sink layer in said contact opening, said oxygen sink layer being capable of absorbing oxygen and being formed as a plurality of spaced oxygen sink layers;
- forming a capacitive element over and in contact with said conductive layer;
- and
- subjecting said capacitive element to a nitrogen/oxygen anneal treatment.
The method of claim 25, wherein said plurality of spaced oxygen sink layers comprises three oxygen sink layers separated by two contacting conductive layers.
A method for fabricating a metal-polysilicon contact in a semiconductor device, comprising the steps of:
- forming an insulating layer over a barrier layer residing over a polysilicon layer;
- forming a contact opening in said insulating layer;
- and
- forming a first oxygen sink spacer in said contact opening, said first oxygen sink spacer being capable of absorbing oxygen;
- forming a first conductive layer in said contact opening and in contact with said first oxygen sink spacer;
- forming a second oxygen sink spacer in said contact opening and in contact with said first conductive layer, said second oxygen sink spacer being capable of absorbing oxygen;
- forming a second conductive layer in said contact opening and in contact with said second oxygen sink spacer, said second conductive layer being in contact with said first conductive layer;
- forming an oxygen sink layer in said contact opening and in contact with said second conductive layer;
- and
- forming a capacitor over said oxygen sink layer and said second conductive layer.
A method of forming a metal-polysilicon contact in a semiconductor device, comprising the steps of:
- forming an insulating layer over a barrier layer residing over a polysilicon layer;
- forming a contact opening in said insulating layer;
- and
- forming a first oxygen barrier layer in said contact opening;
- forming a first oxygen sink spacer in said contact opening and in contact with said first oxygen barrier layer, said first oxygen sink spacer being capable of absorbing oxygen;
- forming a first conductive layer in said contact opening and in contact with said first oxygen sink spacer;
- forming a second oxygen barrier layer in said contact opening and in contact with said first conductive layer;
- forming a second oxygen sink spacer in said contact opening and in contact with said second oxygen barrier layer, said second oxygen sink spacer being capable of absorbing oxygen;
- forming a second conductive layer in said contact opening and in contact with said second oxygen sink spacer, said second conductive layer being in contact with said first conductive layer;
- forming a third oxygen barrier layer in said contact opening and in contact with said second conductive layer;
- forming an oxygen sink layer in said contact opening and in contact with said third oxygen barrier layer;
- and
- forming a capacitor over said oxygen sink layer and said second conductive layer.
Dependencies are inferred from the claim text.