Dual micro-electro mechanical system and manufacturing method thereof

A method of manufacturing a micro electro mechanical system (MEMS), comprising:

• forming first MEMS patterns for a first MEMS structure in a first substrate on a first dielectric layer disposed on a second substrate;
• attaching the first MEMS patterns to a circuit substrate via a second dielectric layer;
• forming a first via hole passing through the second substrate, the first electric layer, the first substrate and the second dielectric layer, and a second via hole passing through the second substrate and the first dielectric layer, a bottom of the second via hole being located in the first substrate;
• forming a first via electrode by filling the first via hole with a conductive material, and a second via electrode by filling the second via hole with the conductive material;
• forming second MEMS patterns for a second MEMS structure in the second substrate;
• and
• releasing the first MEMS patterns and the second MEMS patterns by removing part of the first dielectric layer and part of the second dielectric layer using a chemical dry etching.

A method of manufacturing a micro electro mechanical system (MEMS), comprising:

• forming first MEMS patterns in a first silicon layer of an silicon-on-insulator (SOI) substrate, the SOI substrate including a second silicon layer, a first dielectric layer on the second silicon layer and the first silicon layer on the first dielectric layer;
• attaching the first MEMS patterns to a circuit substrate via a second dielectric layer;
• thinning the second silicon layer;
• forming second MEMS patterns in the thinned second silicon layer;
• releasing the first MEMS patterns and the second MEMS patterns by removing part of the first dielectric layer and part of the second dielectric layer using a chemical dry etching;
• and
• attaching a cover over to the second silicon layer.