Abstract: A method of forming a flower shaped capacitor for a DRAM over a bitline is disclosed. The method comprises the steps of: forming a first polysilicon layer over said bitline; forming a TEOS layer over said first polysilicon layer, patterning and etching an opening through said TEOS layer; depositing a second polysilicon layer; etching back said second polysilicon layer and the first polysilicon layer to form sidewall spacers in said opening; using the first polysilicon layer and sidewall spacers as a mask, etching through to said bitline and thereby removing said TEOS layer; depositing a third polysilicon layer; patterning and etching the third polysilicon layer to form a bottom storage node of the capacitor; and forming a dielectric layer and a top conductive layer over the bottom storage node.

Abstract: A process for forming a narrow field oxide layer with a greater thickness. A silicon substrate is provided on which a layer of pad oxide and a layer of nitride are formed. Then, at least a wide area and a narrow area are defined on the silicon substrate through openings on the nitride layer. A thermal oxidation process is performed so as to grow a first oxide layer on the wide area and a second oxide layer on the narrow area. A polysilicon layer is then deposited over the entire surface. After that, chemical-mechanical polish (CMP) is applied so as to rub away part of the polysilicon layer that is lying above a plane coincident with the topmost surface of the nitride layer, thereby leaving a first polysilicon layer on the first oxide layer and a second polysilicon layer on the second oxide layer. A thermal oxidation process is performed so as to oxidize the first polysilicon layer and the second polysilicon layer, thereby increasing the thickness of the first oxide layer and the second oxide layer.

Abstract: A method of fabricating a via, that reduces contact resistance between two conductive layers. A conductive layer is formed at the periphery of a top surface of a gate. An insulating layer is formed over the gate, and is etched to form a via exposing the top surface of the gate and portions of the conductive layer. The top surface of the gate and the exposed conductive layer form a step profile, which provides extra contact area without increasing the lateral extent of the via.