Thin film interconnects with large grains
The present disclosure relates to integrated circuits and to methods of manufacturing interconnects of integrated circuits. For example, an integrated circuit includes a surface of the integrated circuit and an interconnect formed on the surface and comprising a metal. An average grain size of the metal of the interconnect is greater than or equal to at least half of a line width of the interconnect. In another example, a method for manufacturing an interconnect of an integrated circuit includes depositing a layer of a metal onto a surface of the integrated circuit, annealing the metal, patterning a first hard mask for placement over the metal and forming a line of the interconnect and a first via of the interconnect by performing a timed etch of the metal using the first hard mask.
1. A method for manufacturing an interconnect of an integrated circuit, the method comprising:
depositing a layer of a metal onto a surface of the integrated circuit;
annealing the metal;
patterning a first hard mask for placement over the metal;
forming a line of the interconnect and a first via of the interconnect by performing a timed etch of the metal using the first hard mask;
patterning a second hard mask for placement over the line; and
forming a second via of the interconnect by an etch of the line using the second hard mask, wherein the interconnect exhibits grain continuity between the first via and the line and between the line and the second via, wherein the grain continuity is evident in the line sharing a respective common grain with each of the first via and the second via.
2. The method of claim 1 , wherein the surface comprises a via opening formed by damascene processing for a second via.
3. The method of claim 1 , wherein the line and the first via include at least one common grain of the metal.
4. The method of claim 1 , further comprising polishing and planarizing the metal to a desired thickness and uniformity prior to patterning the metal.
5. The method of claim 1 , wherein the layer of the metal is deposited by at least one of: physical vapor deposition; chemical vapor deposition; or plating.
6. The method of claim 1 , further
comprising: patterning the metal to a line width of the first via by:
patterning and depositing a third hard mask for placement over the metal; and
etching the metal using the third hard mask.
7. A method for manufacturing an interconnect of an integrated circuit, the method comprising:
depositing a layer of a metal onto a surface of the integrated circuit, wherein the surface comprises a via opening, wherein a portion of the metal is deposited in the via opening to form a first via of the interconnect;
annealing the metal;
polishing the metal to a line thickness of a line of the interconnect;
patterning the metal to form at least a portion of the line that is aligned to the first via; and
patterning a portion of the line to form a second via of the interconnect, wherein the line shares a common grain with the first via and the second via.
8. The method of claim 7 , further comprising:
forming a polish stop on the surface prior to the depositing, wherein the polishing comprises polishing the metal until the polish stop is reached.
9. The method of claim 7 , wherein the patterning comprises:
patterning and depositing a hard mask for placement over the metal; and
forming the line by etching the metal using the hard mask.
10. The method of claim 7 , further comprising:
depositing at least one dielectric material at least partially surrounding the interconnect and having a k-value in the range of 1.0 to 2.8.