Abstract: To fabricate a hole trench storage capacitor having an inner electrode, which is formed in a hole trench, and an outer electrode, which is formed in an electrode section, surrounding the hole trench in a lower section, of the semiconductor substrate, the inner electrode is continued above the substrate surface of the semiconductor substrate. Then, an additional layer, which widens the semiconductor substrate, is grown onto the substrate surface by an epitaxy process. A transition surface for contact-connection of the inner electrode and at least a part of an insulation collar is formed above the original substrate surface, thereby increasing the size of a surface area of the hole trench storage capacitor, which can be used for charge storage, while using the same aspect ratio for an etch used to form the hole trench.

Abstract: To fabricate a hole trench storage capacitor having an inner electrode, which is formed in a hole trench, and an outer electrode, which is formed in an electrode section, surrounding the hole trench in a lower section, of the semiconductor substrate, the inner electrode is continued above the substrate surface of the semiconductor substrate. Then, an additional layer, which widens the semiconductor substrate, is grown onto the substrate surface by an epitaxy process. A transition surface for contact-connection of the inner electrode and at least a part of an insulation collar is formed above the original substrate surface, thereby increasing the size of a surface area of the hole trench storage capacitor, which can be used for charge storage, while using the same aspect ratio for an etch used to form the hole trench.