High voltage resistance coupling structure
The disclosed invention provides a structure and method for providing a high lateral voltage resistance between the electrical networks, sharing a lateral plane, of conductive elements (e.g., having different high voltage potentials) comprising a coupler. In one embodiment, an integrated coupler providing a high lateral voltage resistance comprises a primary conductive element and a secondary conductive element. An isolating material is laterally configured between the electrical network of the primary conductive element and an electrical network of the secondary conductive element. The isolating material may comprise a low-k dielectric layer and prevents any lateral barrier layers (e.g., etch stop layers, diffusion barrier layers, etc.) from extending between the first conductive element and the electrical network of the second conductive element. The structure therefore provides a galvanically isolated integrated coupler which avoids electrical shorting between circuits (e.g., at barrier layers) resulting in an improved high voltage resistance.
1. An electrically isolating circuit, comprising:
a primary conductive element comprised within an integrated chip, the primary conductive element comprised within a first electrical network having a first voltage potential;
a secondary conductive element comprised within the integrated chip, the secondary conductive element comprised within a second electrical network located lateral to the primary conductive element and having a second voltage potential; and
an electrically isolating material configured to form an isolation trench disposed laterally disposed between the electrical networks of the primary conductive element and the secondary conductive element, the electrically isolating material forming a homogeneous electrically insulating layer that prevents continuous barrier layers from extending between the electrical networks of the primary conductive element and the secondary conductive element, thereby providing a high lateral voltage resistance between the electrical networks of the primary conductive element and the second electrical network of the secondary conductive element.
2. The electrically isolating circuit of claim 1 , wherein
the primary conductive element comprises a primary conductive coil configured to produce a magnetic field; and
the secondary conductive element comprises a secondary conductive coil configured to sense the magnetic field produced by the primary conductive coil.
3. The electrically isolating circuit of claim 2 ,
wherein the isolation trench vertically extends from above the primary conductive coil to substantially the top of the secondary conductive element, and
wherein the electrically isolating material comprises air having a dielectric constant substantially equal to 1.
4. The electrically isolating circuit of claim 2 , wherein the primary conductive coil comprises a second metal interconnect level and wherein the secondary conductive coil comprises a first metal interconnect level.
5. The electrically isolating circuit of claim 2 , wherein the continuous barrier layers comprise an etch stop layer or a diffusion barrier layer.
6. The electrically isolating circuit of claim 1 , wherein the electrically isolating material comprises an oxide.
7. The electrically isolating circuit of claim 1 , wherein the electrically isolating material comprises a polyimide.
8. The electrically isolating circuit of claim 1 , wherein
the primary conductive element comprises an active circuitry of the integrated chip; and
the secondary conductive element comprises a guard ring of the integrated chip.