There is provided a method for fabricating a substrate structure capable of enhancing process reproducibility and process stability by trimming a bevel region of a substrate using a wafer level process. The method includes providing a first substrate including first and second surfaces opposite each other and a first device region formed at the first surface, providing a second substrate including third and fourth surfaces opposite each other and a second device region at the third surface, bonding the first substrate and the second substrate to electrically connect the first device region and the second device region, and forming a trimmed substrate. The forming the trimmed substrate includes etching an edge region of the second substrate bonded to the first substrate.