Biochip and manufacturing method thereof

A manufacturing method of a biochip, wherein the biochip is configured to detect a biological material in a solution to be tested, and the manufacturing method comprises:

• providing a substrate;
• forming an insulating layer on the substrate;
• forming a semiconductor layer on the insulating layer, wherein the semiconductor layer has a reaction region;
• forming a dielectric layer on the semiconductor layer, wherein the dielectric layer has a first opening;
• forming a metal layer on the dielectric layer, wherein the metal layer comprises:
• a source and a drain, electrically connected to the semiconductor layer respectively;
• and
• a wall structure, surrounding the first opening, the source, and the drain;
• and
• forming a protective layer on the metal layer, wherein the protective layer has a flat part, a protruding part, a second opening, and a third opening;
• wherein the flat part surrounds and defines the second opening, the protruding part is disposed corresponding to the wall structure, and the protruding part surrounds and defines the third opening,
• wherein the second opening connects the third opening and the first opening to expose the reaction region.