METHOD FOR FABRICATING CAPACITOR OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a capacitor of a semiconductor device is provided to guarantee improvement of a step coverage characteristic in depositing barium, strontium and titanium(BST) and forming an upper electrode, by using electrochemical deposit(ECD) Pt to form a BST capacitor. CONSTITUTION: An oxide material and a nitride material(2) are formed on a substrate to insulate the substrate from the capacitor. After a contact hole for a vertical interconnection between the substrate and the capacitor is formed, a doped polycrystalline silicon plug is formed. A plug recess is formed. Ti is deposited on the substrate to reduce contact resistance between the plug and a barrier metal(5). TiSix is formed through a heat treatment process, and the remaining Ti is eliminated. A barrier metal is deposited and planarized. A seed Pt layer(6) is deposited on the substrate. An Al2O3 layer and a chemical vapor deposition(CVD) silicon oxide layer are deposited as a dummy oxide layer. The dummy oxide layer is patterned to form a dummy oxide layer pattern. A part of the CVD silicon oxide layer is removed to form a vertical pattern. Pt is plated in the vertical pattern to form a Pt stack. The dummy oxide layer pattern is removed. The seed Pt layer is removed to insulate storage nodes from each other. A CVD BST layer(10) is deposited on the substrate at a low temperature and is annealed by a rapid thermal process(RTP) method. An upper electrode(11) is formed and patterned on the CVD BAST layer.