Abstract:
The present invention discloses a trench capacitor formed in a trench in a semiconductor substrate. The trench capacitor comprises a bottom electrode positioned on a lower outer surface of the trench, a dielectric layer positioned on an inner surface of the bottom electrode, a top electrode positioned on the dielectric layer, a collar oxide layer positioned on an upper inner surface of the trench, a buried conductive strap positioned on the top electrode, and an interface layer made of silicon nitride positioned at the side of the buried conductive strap. The bottom electrode, the dielectric layer and the top electrode form a capacitive structure. The collar oxide layer includes a first block and a second block, and the height of the first block is larger than the height of the second block. The interface layer is positioned on a portion of the inner surface of the trench above the second block.
Abstract:
A method for manufacturing a shallow trench isolation structure in a deep trench and application thereof are provided, wherein the deep trench having an upper electrode and an insulation layer on the upper electrode is formed in a substrate which has a pad insulation layer. The method comprises the following steps: forming a hard mask on the first insulation layer, doping a first portion of the hard mask, removing the undoped portion of the hard mask to expose a portion of the first insulation layer and reserve the first portion of the hard mask, removing the exposed portion of the first insulation layer to expose a portion of the upper electrode, and forming a conductive layer on the exposed portion of the upper electrode wherein a predetermined distance exists between the upper surface of the conductive layer and the pad insulation layer.