Semiconductor device and method of manufacturing semiconductor device

A disclosed method of manufacturing a semiconductor device includes singulating a bonded substrate including a first substrate provided with an interconnection structure layer and a first bonding layer and a second substrate provided with a second bonding layer opposed to the first bonding layer into a plurality of semiconductor devices. The bonded substrate includes functional element regions and a scribe region in a plan view. The singulating includes forming a groove in the scribe region, and cutting the bonded substrate in a region outside an inner side surface of the groove. The groove is formed penetrating one of the first substrate and the second substrate, the interconnection structure layer, and the first and second bonding layers. The groove extends from the one of the first substrate and the second substrate to a position deeper than all interconnection layers provided between the first and second substrates.