Method for manufacturing double-layer SiN nanopore structure for DNA base sequence detection

The invention provides a method for manufacturing a double-layer SiN nanopore structure for DNA base sequence detection. The method comprises the following steps: firstly, providing a silicon substrate serving as a base plate; depositing a structural layer consisting of three layers of nano films on surfaces of two sides of the substrate by using an LP-CVD process, wherein the three layers of nano films are respectively SiN/SiO2/SiN upwards from the substrate; depositing a sacrificial layer on the surface of the structural layer by using the LP-CVD process; etching the structural layer and the sacrificial layer on one side of the substrate so as to form a substrate release window; etching the silicon substrate by using an alkali solution so as to obtain a self-supported nano film consisting of the structural layer and the sacrificial layer; etching the sacrificial layer above the self-supported nano film so as to obtain a suspended structural layer; etching the suspended structural layer by using helium ion b