Stacked semiconductor device and method of forming the same

摘要

A stacked semiconductor device includes a first substrate. A multilayer interconnect is disposed over the first substrate. Metal sections are disposed over the multilayer interconnect. First bonding features are over the metal sections. A second substrate has a front surface. A cavity extends from the front surface into a depth D in the second substrate. The cavity has an interior surface. A stop layer is disposed over the interior surface of the cavity. A movable structure is disposed over the front surface of the second substrate and suspending over the cavity. The movable structure includes a dielectric membrane, metal units over the dielectric membrane and a cap dielectric layer over the metal units. Second bonding features are over the cap dielectric layer and bonded to the first bonding features. The second bonding features extend through the cap dielectric layer and electrically coupled to the metal units.

主权项

1. A method of forming a stacked semiconductor device, the method comprising:
providing a first substrate having a front surface; etching a portion of the first substrate from the front surface to form a cavity; filling the cavity with a sacrificial material; forming a flexible dielectric membrane over the sacrificial material and the front surface of the first substrate; forming metal units over the flexible dielectric membrane; forming a cap dielectric layer over the metal units and the flexible dielectric membrane; etching portions of the cap dielectric layer to expose the metal units; forming first bonding features over the cap dielectric layer and contacting the metal units; etching portions of the cap dielectric layer and the flexible dielectric membrane, thereby forming through-holes to expose portions of the sacrificial material; removing the sacrificial material through the through-holes from the cavity, thereby forming a movable structure including the flexible dielectric membrane, the metal units and the cap dielectric layer suspending over the cavity; providing a second substrate having at least one transistor disposed over the second substrate; forming a multilayer interconnect over the at least one transistor and electrically coupled to the at least one transistor; forming metal sections over the multilayer interconnect; forming second bonding features over portions of the metal sections; and bonding the second bonding features to the first bonding features.