An integrated circuit device comprises a substrate, a stack structure including circuit structure having conductive lines positioned on the substrate, a reinforcement structure including at least one supporting member positioned on the substrate and a roof covering the circuit structure and the supporting member and at least one bonding pad positioned on the roof and electrically connected to the conductive lines. A method for preparing an integrated circuit device comprises forming a stack structure including circuit structure having conductive lines on a substrate, forming a reinforcement structure including at least one supporting member on the substrate and a roof covering the supporting member and the circuit structure and forming at least one bonding pad on the roof and electrically connecting to the conductive lines.