Air bridge structure and manufacturing method thereof, and superconducting quantum chip and manufacturing method thereof

A manufacturing method for an air bridge structure, comprising:

• forming a first photoresist structure on a substrate, the first photoresist structure comprising a first photoresist layer on the substrate and a second photoresist layer on the first photoresist layer, the first photoresist structure comprising a first opening that reveals the substrate, the first opening comprising a first sub-opening through the second photoresist layer and a second sub-opening through the first photoresist layer, a first width of the first sub-opening being less than a second width of the first sub-opening such that widths of the first sub-opening decrease with increasing distance from the substrate, and the second width of the first sub-opening through the second photoresist layer being greater than a width of the second sub-opening through the first photoresist layer;
• forming a bridge supporting structure on the substrate, (i) both the bridge supporting structure and the first photoresist structure being sacrificial structures, (ii) the bridge supporting structure being arranged in the first opening in the first photoresist structure and having a sloped profile that is formed based on the first width of the first sub-opening being less than the second width of the first sub-opening, (iii) both the bridge supporting structure and the first photoresist layer being directly deposited on the substrate, and (iv) a height of the bridge supporting structure being larger than a height of the first photoresist layer;
• stripping the first photoresist structure after the deposition of the bridge supporting structure;
• forming a second photoresist structure on the substrate, the second photoresist structure comprising at least a second opening that reveals at least a portion of the bridge supporting structure on the substrate;
• and
• forming the air bridge structure by depositing an air bridge material on the substrate based on the second opening and stripping the second photoresist structure after the deposition of the air bridge material.