Stacked semiconductor device and a method of forming

The present invention provides a stacked semiconductor device comprising a first substrate. The multilayer interconnect disposed over the first substrate. Metal portion disposed above the multi-layer interconnect. The first engaging member located above the metal portion. The second substrate having a front. A second cavity extending from the front substrate to a depth D. The cavity has an inner surface. Stop layer is disposed above the inner surface of the cavity. Movable structure disposed above the front surface of the second substrate and suspended in the upper chamber. Movable structure includes a dielectric film, a dielectric located above the metal film and the electrical unit is located above the metallic layer covering the dielectric unit. The second engagement member is located over the dielectric layer and cover joined to the first joint member. Covering the second engagement member extends through the dielectric layer and electrically connected to the metal element. The present invention further provides a method of forming a stacked semiconductor device.