Structure with conductive plug and method of forming the same
Provided is a structure with a conductive plug including a substrate, a first dielectric layer, an etch stop layer, a second dielectric layer, a conductive plug and a liner. The substrate has a conductive region therein. The first dielectric layer, the etch stop layer and the second dielectric layer are sequentially formed on the substrate and have at least one opening therethrough. Besides, the opening has a substantially vertical sidewall. The conductive plug fills in the opening and is electrically connected to the conductive region. The liner surrounds the upper portion of the conductive plug. A method of forming a structure with a conductive plug is further provided.
1. A structure with a conductive plug, comprising:
a substrate, having a conductive region therein;
a first dielectric layer, an etch stop layer and a second dielectric layer, sequentially disposed on the substrate, wherein a portion of the first dielectric layer and a portion of the etch stop layer are disposed on the conductive region, wherein at least one opening penetrates through the first dielectric layer, the etch stop layer and the second dielectric layer;
a conductive plug, filling in the opening and electrically connected to the conductive region, wherein the conductive plug has a side surface and a bottom surface, and the bottom surface of the conductive plug is in direct contact with the conductive region; and
a liner, disposed on the etch stop layer and surrounding a portion of the side surface of the conductive plug.
2. The structure of claim 1 , wherein an aspect ratio of the opening ranges from about 2:1 to 40:1.
3. The structure of claim 1 , wherein the liner is only disposed between the conductive plug and the second dielectric layer and is in contact with the etch stop layer.
4. The structure of claim 1 , wherein the etch stop layer comprises silicon nitride, silicon oxynitride or a combination thereof.
5. The structure of claim 1 , wherein the liner comprises polysilicon, amorphous silicon, silicon nitride, silicon oxynitride or a combination thereof.
6. The structure of claim 1 , wherein a thickness ratio of the second dielectric layer to the first dielectric layer is about 1:1 to 20:1.
7. The structure of claim 1 , wherein a thickness ratio of the first dielectric layer to the etch stop layer is about 2:1 to 10:1.
8. The structure of claim 1 , wherein a thickness ratio of the etch stop layer to the liner is about 5:3 to 5:1.
9. The structure of claim 1 , wherein the conductive plug comprises:
a barrier layer, disposed on a surface of the opening; and
a metal layer, filling up the opening.
10. The structure of claim 1 , wherein the conductive region comprises a doped region, a gate or a wire.