Microelectronic devices with through-silicon vias and associated methods of manufacturing
View Patent ↗Microelectronic devices with through-silicon vias and associated methods of manufacturing such devices. One embodiment of a method for forming tungsten through-silicon vias comprising forming an opening having a sidewall such that the opening extends through at least a portion of a substrate on which microelectronic structures have been formed. The method can further include lining the sidewall with a dielectric material, depositing tungsten on the dielectric material such that a cavity extends through at least a portion of the tungsten, and filling the cavity with a polysilicon material.
1. A method for forming tungsten through-silicon vias, comprising:
forming an opening having a sidewall extending through at least a portion of a semiconductor substrate on which semiconductor components have been formed, wherein the opening is formed by etching the opening completely through a first interlayer dielectric structure and through only a portion of the semiconductor substrate such that the opening has a closed end in the semiconductor substrate, and wherein a metallization structure is on an upper surface of the first interlayer dielectric structure;
forming a second interlayer dielectric structure on the first interlayer dielectric structure and a dielectric liner along the sidewall of the opening in a single process using the same material, the second interlayer dielectric structure is formed by depositing a first portion of a dielectric material on the first interlayer dielectric structure and over the metallization structure, the dielectric liner is formed by depositing a second portion of the dielectric material into the opening such that it lines the sidewall of the opening, and the first portion of the dielectric material has a thickness greater than that of the metallization structure;
forming a tungsten conductor along the dielectric liner, wherein the tungsten conductor partially fills the opening such that a cavity extends into the tungsten conductor; and
depositing polysilicon into the cavity in the tungsten conductor.
2. The method of claim 1 , wherein:
depositing polysilicon comprises depositing a first portion of polysilicon on the first portion of the tungsten and filling the cavity in the tungsten conductor with a second portion of polysilicon; and
the method further comprises removing the first portion of the polysilicon and the first portion of the tungsten such that the first portion of the dielectric material is exposed.
3. The method of claim 2 wherein the first and second portions of the tungsten are contiguous with each other, and the first and second portions of the polysilicon are contiguous with each other.
4. The method of claim 2 , further comprising:
forming a second opening through the second interlayer dielectric structure to a metallization structure on the first interlayer dielectric structure;
forming a third opening through the second interlayer dielectric structure and the first interlayer dielectric structure to the semiconductor components; and
filling the second and third openings with a conductive material.
5. The method of claim 4 , further comprising removing material from a backside of the semiconductor substrate until the tungsten conductor and polysilicon at a bottom of the opening are exposed.
6. The method of claim 1 , further comprising removing a portion of the first portion of dielectric material that forms the second interlayer dielectric structure to form an upper surface of the second dielectric structure at an elevation above the metallization structure on the first interlayer dielectric structure.
7. The method of claim 1 , wherein the tungsten conductor has a thickness of about 3 μm.
8. A method for forming tungsten through-silicon vias, comprising:
forming an opening having a sidewall, wherein the opening extends through at least a first interlayer dielectric structure and through at least a portion of a substrate on which microelectronic components have been formed, and wherein a metallization structure is on an upper surface of the first interlayer dielectric structure;
forming a second interlayer dielectric structure on the first interlayer dielectric structure and a dielectric liner along the sidewall of the opening in a single process using the same material, the second interlayer dielectric structure is formed by depositing a first portion of a dielectric material on the first interlayer dielectric structure and over the metallization structure, the dielectric liner is formed by depositing a second portion of the dielectric material into the opening such that it lines the sidewall of the opening, and the first portion of the dielectric material has a thickness greater than that of the metallization structure;
depositing tungsten on the dielectric material such that a cavity extends through at least a portion of the tungsten; and
filling the cavity with polysilicon.
9. The method of claim 8 , wherein:
depositing the tungsten comprises depositing a first portion of tungsten on the first interlayer dielectric structure and a second portion of tungsten into the opening such that the second portion of tungsten conforms to the second portion of the dielectric material in the opening;
filling the cavity with polysilicon comprises depositing a first portion of polysilicon on the first portion of the tungsten and filling the cavity in the tungsten with a second portion of polysilicon; and
the method further comprises removing the first portion of the polysilicon and the first portion of the tungsten such that the first portion of the dielectric material is exposed.
10. The method of claim 9 , wherein the first and second portions of the tungsten are contiguous with each other, and the first and second portions of the polysilicon are contiguous with each other.
11. The method of claim 9 , further comprising:
forming a first opening through the second interlayer dielectric structure to a metallization structure on the first interlayer dielectric structure;
forming a second opening through the second interlayer dielectric structure and the first interlayer dielectric structure to the semiconductor components; and
filling the first and second openings with a conductive material.
12. The method of claim 11 , further comprising removing material from a backside of the semiconductor substrate until the tungsten conductor and polysilicon at a bottom of the opening are exposed.
13. The method of claim 8 , further comprising forming an array of a plurality tungsten through-silicon vias in a region sized for a single copper through-silicon via by forming a plurality of the openings in the region, forming a dielectric liner along each opening, forming a tungsten conductor in each opening, and depositing the polysilicon into the tungsten conductors.
14. The method of claim 8 , further comprising removing a portion of the first portion of dielectric material that forms the second interlayer dielectric structure to form an upper surface of the second dielectric structure at an elevation above the metallization structure on the first interlayer dielectric structure.
15. The method of claim 8 , wherein the tungsten conductor has a thickness of about 3 μm.