Semiconductor structure with staggered selective growth

A semiconductor structure, comprising:

• a semiconductor substrate;
• a first conductive feature and a second conductive feature disposed on the semiconductor substrate;
• a first via feature and a second via feature landing on the first and second conductive features, respectively;
• and
• a staggered dielectric feature spans between a first edge of the first via feature and a second edge of the second via feature, wherein
• the staggered dielectric feature includes a plurality of first dielectric layers and a plurality of second dielectric layers being interdigitated,
• the first dielectric layers include a first dielectric material and the second dielectric layers include a second dielectric material being different from the first dielectric material,
• each of the first dielectric layers continuously extends from the first edge to the second edge, and has a first varying thickness decreased from the first edge to the second edge, and
• each of the second dielectric layers continuously extends from the first edge to the second edge, and has a second varying thickness increased from the first edge to the second edge.

A method, comprising:

• providing a semiconductor structure having a first conductive feature in a first region, a second conductive feature in a second region, and a dielectric spacer in a third region and interposed between the first and second conductive features;
• selectively depositing a first dielectric layer of a first dielectric material in the first region, wherein the selectively depositing of the first dielectric layer includes laterally extends the first dielectric layer to the third region;
• selectively depositing a second dielectric layer of a second dielectric material in the second region, wherein the selectively depositing of the second dielectric layer includes laterally extends the second dielectric layer to the third region, wherein the second dielectric material is different from the first dielectric material in composition;
• and
• performing a first etching process to selectively etch the first dielectric material, thereby forming a first trench in the first region and leaving a staggered dielectric feature of the first and second dielectric materials in the third region.