Alternatively, in some other embodiments, a third photoresist is coated on the substrate and the bridge brace material as the patterned photoresist mentioned above, and the temperature of third baking is a soft baking temperature of the third photoresist. The third photoresist and the second photoresist are different photoresists. The third photoresist is a negative or reversal photoresist.

At Step 403. Exposure patterning treatment is performed on the patterned photoresist based on an opening requirement of the air bridge.

The opening requirement includes a position requirement of an opening on a deck of the air bridge. In this embodiment of this disclosure, the opening on the air bridge mainly involves three positions: 1. an approach bridge portion; 2. the approach bridge portion and a pier portion; and 3. a bridge top portion. In this embodiment of this disclosure, in view of different positions of the opening, two fabrication methods are provided.

A method A and a method B are described. In the method A, the patterned photoresist is directly exposed and patterned to obtain an opening structure, so as to obtain an air bridge having the opening after deposition of the bridge material.

In the method B, a region on the patterned photoresist corresponding to the bridge brace material is exposed, to obtain a patterned complete bridge region. The bridge material is deposited. Then, the photoresist used for fabricating an opening is patterned to perform opening arrangement again. Finally, the bridge material is etched through an opening region of the photoresist used for fabricating an opening, to obtain the opening on the air bridge.

Therefore, in this embodiment, performing exposure patterning treatment on the patterned photoresist based on the opening requirement has two meanings: