Method for manufacturing a semiconductor device

A method for manufacturing a semiconductor device, comprising the steps of:

• forming a first impurity region on a first surface of a first semiconductor substrate;
• forming a trench isolation region on said first surface for defining an active region within the first semiconductor substrate;
• depositing a first conductive material on said active region and patterning said conductive material to form a first electrode of a capacitor;
• forming a dielectric film on said first electrode;
• depositing a second conductive material on said dielectric film to form a second electrode of said capacitor;
• etching said first semiconductor substrate on a second surface thereof located on an opposite side of the substrate from said first surface;
• selectively etching said second surface of the substrate to form a pillar, said pillar being spaced apart from said trench isolation region to form an opening in said second surface of the substrate;
• implanting an impurity in said opening to form a second impurity region in said second surface of the first semiconductor substrate;
• forming a first insulating layer on an exposed surface of said pillar;
• depositing a conductive material on said first insulating layer to form a conductive layer surrounding said pillar;
• forming a second insulating layer of said conductive layer;
• patterning said second insulating layer, said conductive layer and said first insulating layer to form a gate electrode and a contact hole which exposes an upper surface of the pillar;
• forming a spacer on a sidewall of the contact hole;
• and
• implanting an impurity in said upper surface of the pillar.