Abstract: A semiconductor structure having micro-electro-mechanical system (MEMS) devices is provided. One of the MEMS devices includes a substrate having a first region and a second region; a membrane structure formed in the first region and positioned correspondingly to a cavity of the substrate; a logic device formed in the second region, and electrically connected to the membrane structure; an interconnection structure formed in the second region, and the interconnection structure formed on the substrate and covering the logic device; and an etching stop layer formed in the second region, and the etching stop layer formed on the interconnection structure and including a nitride layer and a carbon-containing layer formed on the nitride layer. Also, a variation in resonant frequencies of the MEMS devices on the entire wafer is less than 10%.