Photovoltaic devices with conducting layer interconnects
According to the embodiments provided herein, an island in a regular, closed shape is ablated in a first conductive layer. An interconnect is formed through the island, using the island as an alignment fiducial. The island and the interconnect are isolated from the remainder of the first conductive layer.
1. A method for forming a conductive interconnection comprising:
forming a semiconductor stack over a first contact;
forming a first conductive layer over the semiconductor stack; and
ablating a shaped region of the first conductive layer from the semiconductor stack, wherein a conductive island is formed from the first conductive layer and demarcated by the shaped region;
forming a dielectric layer over the first conductive layer;
forming a passage through the conductive island of the first conductive layer, the passage extending through the dielectric layer, the conductive island of the first conductive layer, and the semiconductor stack; and
filling the passage, at least partially, with an interconnect that forms an electrical connection with the first contact.
2. The method of claim 1 , further comprising forming the passage such that a portion of the conductive island remains after the passage forming step.
3. The method of claim 1 , further comprising forming the passage such that the entire conductive island is removed by the passage forming step.
4. The method of claim 1 , further comprising forming the dielectric layer to partially fill the shaped region.
5. The method of claim 1 , further comprising forming a second conductive layer adjoining the dielectric layer.
6. The method of claim 5 , wherein the second conductive layer forms at least a portion of the interconnect.
7. The method of claim 1 , further comprising performing the ablating in the shape of an annular scribe ring to thereby separate and electrically isolate the conductive island from the first conductive layer.
8. The method of claim 7 , wherein the annular scribe ring is produced using a focal lens and a diffractive axicon.