METHOD OF FORMING CAPACITOR OF SEMICONDUCTOR DEVICE USING NITRIDE LAYER AS PHOSPHOR DIFFUSION BARRIER TO SECURE HIGH PHOSPHOR CONCENTRATION IN DEPLETION REGION CAPACITOR

摘要

PURPOSE: A method of forming a capacitor of a semiconductor device is provided to secure high phosphor concentration in a depletion region capacitor by using a nitride layer formed on a lower electrode as a phosphor diffusion barrier. CONSTITUTION: An interlayer dielectric(24) with plugs(25) and a capacitor oxide layer(26) with trenches(27) for exposing the plugs are sequentially formed on a silicon substrate(21). An undoped amorphous silicon layer and a doped amorphous silicon layer(28) are formed in the trench. A lower electrode is formed by growing hemi-spherical silicon grains on the undoped amorphous silicon layer using annealing. An oxide layer(30) is formed on the lower electrode. P ions are implanted into the oxide layer. A nitride layer(31) is formed by nitriding the surface of the oxide layer.