DEEP TRENCH DEVICE WITH SINGLE SIDED CONNECTING STRUCTURE AND FABRICATION METHOD THEREOF

摘要

A deep trench device with a single sided connecting structure. The device comprises a substrate having a trench therein. A buried trench capacitor is disposed in a lower portion of the trench. An asymmetric collar insulator is disposed on an upper portion of the sidewall of the trench. A connecting structure is disposed in the upper portion of the trench, comprising an epitaxial silicon layer disposed on and adjacent to a relatively low portion of the asymmetric collar insulator and a connecting member disposed between the epitaxial silicon layer and a relatively high portion of the asymmetric collar insulator. A conductive layer is disposed between the relatively high and low portions of the asymmetric collar insulator, to electrically connect the buried trench capacitor and the connecting structure. A cap layer is disposed on the connecting structure. A fabrication method for a deep trench device is also disclosed.