Conductive plug structure and fabrication method thereof
The present disclosure provides conductive plug structures and fabrication methods thereof. An exemplary fabrication process of the conductive plug structure includes providing a substrate; forming a mask layer having an opening on a surface of the substrate; etching the substrate to form a contact hole using the mask layer as an etching mask; etching the mask layer to increase a feature size of the opening; forming an insulation layer on an inner surface of the opening, an inner surface of the enlarged opening and a surface of the mask layer to have more edge corners, a thickness of the insulation layer being greater than a thickness of the remaining mask layer; forming a conductive layer filling the contact hole on the insulation layer; and planarizing the conductive layer and the insulation layer until a surface of the mask layer is exposed.
1. A method for fabricating a conductive plug structure, comprising:
providing a substrate;
forming a mask layer having an opening on a surface of the substrate;
etching the substrate to form a contact hole using the mask layer as an etching mask;
after forming the contact hole using the mask layer as the etching mask, etching the mask layer to increase a feature size of the opening;
forming an insulation layer on an inner surface of the opening, an inner surface of the enlarged opening and a surface of the mask layer to have more edge corners, a thickness of the insulation layer being greater than a thickness of the remaining mask layer;
forming a conductive layer filling the contact hole on the insulation layer; and
planarizing the conductive layer and the insulation layer until a surface of the mask layer is exposed.
2. The method according to claim 1 , wherein:
a ratio between a feature size of the enlarged opening and a feature size of the contact hole is in a range of approximately 1.02-1.1.
3. The method according to claim 1 , wherein:
the mask layer is made of one of silicon oxide and silicon nitride; and
the mask layer is etched by a wet etching process;
an etching solution of the wet etching process is a phosphorous acid solution;
a mass concentration of the phosphorous acid solution is in a range of approximately 80%-90%; and
a temperature of the wet etching process is in a range of approximately 120° C.-180° C.
4. The method according to claim 1 , wherein:
a thickness of the remaining mask layer is in a range of approximately 800 Å-1200 Å.
5. The method according to claim 1 , wherein:
the conductive layer is made of one of Ta, TaN, and Cu;
the conductive layer is formed by an electroplating process; and
the conductive layer and the insulation layer are planarized by a chemical mechanical polishing process.
6. The method according to claim 1 , wherein:
the insulation layer is made of silicon oxide; and
the insulation layer is formed by an atomic layer deposition process.
7. A method for fabricating a conductive plug structure, comprising:
providing a substrate;
forming a mask layer having an opening on a surface of the substrate;
etching the substrate to form a contact hole using the mask layer as an etching mask;
after forming the contact hole using the mask layer as the etching mask, etching the mask layer to increase a feature size of the opening;
forming an Insulation layer on an inner surface of the opening, an inner surface of the enlarged opening and a surface of the mask layer to have more edge corners, a thickness of the insulation layer being greater than a thickness of the remaining mask layer;
forming a barrier layer on the insulation layer;
forming a conductive layer filling the contact hole on the barrier layer; and
planarizing the conductive layer, the barrier layer and the insulation layer until a surface of the mask layer is exposed.
8. The method according to claim 7 , wherein:
the barrier layer is made of one of TiN and TaN; and
the barrier layer is formed by a physical vapor deposition process.
9. The method according to claim 7 , wherein:
a ratio between a feature size of the enlarged opening and a feature size of the contact hole is in a range of approximately 1.02-1.1.
10. The method according to claim 7 , wherein:
the mask layer is made of one of silicon oxide and silicon nitride; and
the mask layer is etched by a wet etching process;
an etching solution of the wet etching process is a phosphorous acid solution;
a mass concentration of the phosphorous acid solution is in a range of approximately 80%-90%; and
a temperature of the wet etching process is in a range of approximately 120° C.-180° C.
11. The method according to claim 7 , wherein:
a thickness of the remaining mask layer is in a range of approximately 800 Å-1200 Å.
12. The method according to claim 7 , wherein:
the conductive layer is made of one of Ta, TaN, and Cu;
the conductive layer is formed by an electroplating process; and
the conductive layer and the insulation layer are planarized by a chemical mechanical polishing process.
13. The method according to claim 7 , wherein:
the insulation layer is made of silicon oxide; and
the insulation layer is formed by an atomic layer deposition process.
14. A conductive plug structure, comprising:
a substrate;
a conductive layer penetrating into the substrate; and
an insulation layer formed between the substrate and the conductive layer,
wherein the conductive layer is formed by:
forming a mask layer having an opening on a surface of the substrate;
etching the substrate to form a contact hole using the mask layer as an etching mask;
after forming the contact hole using the mask layer as the etching mask, etching the mask layer to increase a feature size of the opening;
forming an insulation layer on an inner surface of the opening, an inside surface of the enlarged opening and a surface of the mask layer to have more edge corners, a thickness of the insulation layer being greater than a thickness of the remaining mask layer;
forming a conductive layer filling the contact hole on the insulation layer; and
planarizing the conductive layer and the insulation layer until a surface of the mask layer is exposed.
15. The conductive plug structure according to claim 14 , further comprising:
a barrier layer formed between the insulation layer and the conductive layer.
16. The conductive plug structure according to claim 15 , wherein:
the barrier layer is made of one of TaN and TiN.
17. The conductive plug structure according to claim 14 , wherein:
the mask layer is made of silicon nitride; and
the thickness of the mask layer is in a range of approximately 800 Å-1200 Å.
18. The conductive plug structure according to claim 14 , wherein:
the conductive layer is made of one of Ta, TaN, and Cu.
19. The conductive plug structure according to claim 14 , wherein:
the insulation layer is made of silicon oxide.
20. The conductive plug structure according to claim 14 , wherein:
a ratio between a feature size of the enlarged opening and a feature size of the contact hole is in a range of approximately 1.02-1.1.