Semiconductor device structure with composite bottle-shaped through silicon via

A semiconductor device structure, comprising:

• a silicon layer disposed over a first semiconductor die;
• a first mask layer disposed over the silicon layer;
• a second mask layer disposed over the first mask layer;
• a second semiconductor die disposed over the second mask layer;
• and
• a through silicon via penetrating through the silicon layer, the first mask layer and the second mask layer to electrically connect the first semiconductor die and the second semiconductor die;
• wherein the through silicon via includes a lower conductor, a graphene layer disposed on the lower conductor and an upper conductor disposed in the graphene layer;
• wherein the through silicon via has a bottle-neck shaped portion surrounded by the first mask layer and an upper portion of the silicon layer, and an interface area between the through silicon via and the first semiconductor die is greater than an interface area between the through silicon via and the second semiconductor die;
• wherein the through silicon via comprises:
• a conductive layer;
• and
• a barrier layer covering sidewalls and a bottom surface of the conductive layer, wherein the barrier layer is in direct contact with the first semiconductor die.