Antenna protection on dummy metal fills
A memory device can include a semiconductor substrate having a plurality of active semiconductor devices. The memory device can include a plurality of metallization layers disposed over the semiconductor substrate, where each of the plurality of metallization layers is separated from adjacent metallization layers by an interlayer dielectric. The memory device also includes a dummy metal fill disposed in a metallization layer. The dummy metal fill can be connected to a discharge path for dissipating a charge build up in the dummy metal fill to minimize antenna effects. In some embodiments, the discharge path can include the semiconductor substrate, which can be an electrical drain. The antenna protected dummy metal fill ensures is configured such that any accumulated charge during the fabrication process is discharged to the electric drain.
1 . A memory device, comprising:
a semiconductor substrate including a plurality of active semiconductor devices; and
a plurality of metallization layers disposed over the semiconductor substrate, each of the plurality of metallization layers separated from adjacent metallization layers by an interlayer dielectric, wherein the plurality of metallization layers comprises a metallization layer comprising:
a first dummy metal fill connected to a first discharge path for dissipating, through a first via conductor, a first charge build up in the first dummy metal fill to minimize antenna effects,
a second dummy metal fill connected to a second discharge path for dissipating, through a second via conductor, a second charge build up in the second dummy metal fill to minimize antenna effects,
a floating dummy metal fill,
first live metal positioned between the first dummy metal fill and the floating dummy metal fill, wherein:
a first minimum distance between the first dummy metal fill and the first live metal is less than a threshold distance based on the first dummy metal fill being connected to the first discharge path,
a second minimum distance between the floating dummy metal fill and the first live metal is greater than or equal to the threshold distance based on the floating dummy metal fill not being connected to any discharge path, and
the first minimum distance between the first dummy metal fill and the first live metal is less than half of the second minimum distance between the floating dummy metal fill and the first live metal, and
second live metal positioned between the second dummy metal fill and the floating dummy metal fill, wherein:
a third minimum distance between the second dummy metal fill and the second live metal is less than the threshold distance based on the second dummy metal fill being connected to the second discharge path, and
a fourth minimum distance between the floating dummy metal fill and the second live metal is greater than or equal to the threshold distance based on the floating dummy metal fill not being connected to any discharge path.
2 . The memory device of claim 1 , wherein the first discharge path includes the semiconductor substrate, and wherein the semiconductor substrate is an electrical drain.
3 . The memory device of claim 1 , wherein:
the first via conductor is connected between the first dummy metal fill and at least one of the semiconductor substrate or a third dummy metal fill disposed on a second metallization layer, and
the first discharge path includes the first via conductor.
4 . The memory device of claim 3 , wherein the first via conductor connects the first dummy metal fill and the third dummy metal fill in an overlap portion of the first dummy metal fill and the third dummy metal fill.
5 . The memory device of claim 3 , wherein the first dummy metal fill and the third dummy metal fill do not overlap, and wherein a width of the first via conductor is such that the first via conductor connects the first dummy metal fill and the third dummy metal fill.
6 . The memory device of claim 1 , wherein the first dummy metal fill is disposed within a first grid of the metallization layer associated with a first metal pattern density and the second dummy metal fill is disposed in a second grid of the metallization layer associated with a second metal pattern density.
7 . The memory device of claim 1 , wherein the first dummy metal fill is not directly connected to an active semiconductor device of the plurality of active semiconductor devices.
8 . A method, comprising:
depositing a plurality of metallization layers over a semiconductor substrate of a memory device, each of the plurality of metallization layers separated from adjacent metallization layers by an interlayer dielectric and the semiconductor substrate including a plurality of active semiconductor devices;
depositing a first dummy metal fill in a metallization layer of the plurality of metallization layers;
configuring a first discharge path for the first dummy metal fill for dissipating, through a first via conductor, a first charge build up in the first dummy metal fill to minimize antenna effects;
depositing a second dummy metal fill in the metallization layer;
configuring a second discharge path for the second dummy metal fill for dissipating, through a second via conductor, a second charge build up in the second dummy metal fill to minimize antenna effects;
depositing a floating dummy metal fill in the metallization layer;
depositing first live metal in the metallization layer, the first live metal being positioned between the first dummy metal fill and the floating dummy metal fill, wherein:
a first minimum distance between the first dummy metal fill and the first live metal is less than a threshold distance based on the first dummy metal fill being connected to the first discharge path,
a second minimum distance between the floating dummy metal fill and the first live metal is greater than or equal to the threshold distance based on the floating dummy metal fill not being connected to any discharge path, and
the first minimum distance between the first dummy metal fill and the first live metal is less than half of the second minimum distance between the floating dummy metal fill and the first live metal; and
depositing second live metal in the metallization layer, the second live metal being positioned between the second dummy metal fill and the floating dummy metal fill, wherein:
a third minimum distance between the second dummy metal fill and the second live metal is less than the threshold distance based on the second dummy metal fill being connected to the second discharge path, and
a fourth minimum distance between the floating dummy metal fill and the second live metal is greater than or equal to the threshold distance based on the floating dummy metal fill not being connected to any discharge path.
9 . The method of claim 8 , wherein the first discharge path includes the semiconductor substrate of the memory device, and wherein the semiconductor substrate is an electrical drain.
10 . The method of claim 8 , further comprising:
depositing the first via conductor between the first dummy metal fill and at least one of the semiconductor substrate or a third dummy metal fill disposed on a second metallization layer such that the first discharge path includes the first via conductor.
11 . The method of claim 8 , further comprising:
depositing a merge fill between the first dummy metal fill and a third second dummy metal fill disposed in the metallization layer such that the first discharge path includes the merge fill.
12 . The method of claim 8 , wherein the first dummy metal fill is not directly connected to an active semiconductor device of the plurality of active semiconductor devices.
13 . The memory device of claim 1 , wherein the first minimum distance between the first dummy metal fill and the first live metal is less than or equal to half of the threshold distance.
14 . The memory device of claim 1 , wherein the third minimum distance between the second dummy metal fill and the second live metal is less than half of the fourth minimum distance between the floating dummy metal fill and the second live metal.
15 . The memory device of claim 1 , wherein the third minimum distance between the second dummy metal fill and the second live metal is less than or equal to half of the threshold distance.