Environmental sensor and manufacturing method thereof

An environmental sensor comprising:

• a base material (1), wherein the upper end of the base material (1) is provided with at least one groove (1a);
• a fixed film layer (8) at least disposed on the side wall of the groove (1a) of the base material (1) by an insulating layer;
• and
• a sensitive film layer (3) on the base material (1), the sensitive film layer (3) comprises a fixed part (3b) fixed on the end surface of the base material (1) and a bending part (3a) extending into the groove (1a), the bending part (3a) and the side wall of the fixed film layer (8) form a capacitor configured for signal detection;
• wherein:
• the bending part (3a), the fixed part (3b) and the groove (1a) form an airtight cavity, and
• the sensitive film layer (3) further comprises a connecting part (3d) connected to two adjacent bending parts (3a), and the connecting part (3d) is suspended above the end surface of the base material (1).

A manufacturing method for an environmental sensor, the method comprising:

• a) etching a groove (1a) in the upper end surface of a base material (1), and depositing a first sacrificial layer (2) on the upper end surface of the base material (1) and the inner wall of the groove (1a);
• b) depositing a sensitive film layer (3) on the first sacrificial layer (2), wherein the sensitive film layer (3) comprises a fixed part (3b) fixed on the end surface of the base material (1) and a bending part (3a) extending into the groove (1a);
• c) etching the sensitive film layer (3) on the end surface of the base material (1) to form a hollow (3c);
• d) at least corroding the first sacrificial layer (2) located between the bending part (3a) and the side wall of the groove (1a) by the hollow (3c);
• e) depositing a second sacrificial layer (4) on the sensitive film layer (3), wherein the second sacrificial layer (4) seals the hollow (3c);
• and
• f) corroding the second sacrificial layer (4) located on the bending part (3a).