A method includes forming a recess in a first substrate, bonding a micro-electro-mechanical systems (MEMS) substrate to the first substrate after forming the recess in the first substrate, forming an anti-stiction layer over the micro-electro-mechanical systems (MEMS) substrate, pattering the anti-stiction layer, etching the MEMS substrate to form a MEMS device, and bonding the MEMS device and the first substrate to a second substrate. The patterned anti-stiction layer is between the MEMS device and the second substrate.