Biochip and manufacturing method thereof

A manufacturing method of a biochip, comprising:

• providing a substrate;
• forming a first insulation layer on the substrate;
• forming a semiconductor layer on the first insulation layer, wherein the semiconductor layer comprises a plurality of reaction regions;
• forming a second insulation layer on the semiconductor layer, wherein the second insulation layer comprises:
• a first part;
• a second part, surrounding the first part;
• and
• a first opening, separating the first part and the second part and exposing the reaction regions;
• forming a first metal layer on the second part, wherein the first metal layer comprises a source electrode, a drain electrode, a gate electrode, and a first wall structure that are separated from each other;
• forming a second metal layer, wherein the second metal layer comprises:
• a second wall structure, disposed on the first wall structure;
• and
• a biological electrode, disposed on the first part;
• and
• forming a protection layer on the first metal layer and the second metal layer, wherein the protection layer has a second opening, a third opening and a fourth opening, and comprises:
• a flat part, covering the second part exposed by the first metal layer, and surrounding and defining the second opening;
• a first protruding part, covering the source electrode, the drain electrode, and the gate electrode, and surrounding and defining the third opening;
• and
• a second protruding part, covering the second wall structure, and surrounding and defining the fourth opening;
• wherein in a normal direction of the substrate, the first opening, the second opening, the third opening, and the fourth opening overlap.