Importance

Loading Importance Indicators...

Abstract

A process for fabricating a DRAM semiconductor memory device having a transfer transistor and a storage capacitor with a tree-shaped electrode. The tree-shaped electrode is electrically coupled to a source/drain region of the transistor. The process includes forming a first insulation layer on the device substrate covering the transfer transistor. A first electrically conductive layer is formed over and penetrating the first insulation layer such that it is electrically coupled to the source/drain region. Cylindrical structures are formed on the first conductive layer, forming a recess between the cylindrical structures. A second insulation layer covering the cylindrical structures and a portion of the exposed first electrically conductive layer is formed, with the second insulation layer covering bottom portion of the recesses incompletely. A second electrically conductive layer covering the second insulation layer and the exposed portion of the first conductive layer is formed. Portions of the first and second conductive layers above the cylindrical structures are removed to section the conductive layers, forming tree-trunk and tree-limb portions of the tree-shaped electrode, respectively. The second insulation layer and the cylindrical structures are removed. A dielectric layer is formed over the sectioned first and second conductive layers. A third electrically conductive layer is formed over the dielectric layer, forming an opposing electrode of the capacitor.

Loading the Abstract Image...

First Claim