METHOD OF FORMING MEMORY DEVICE HAVING CAPACITOR INCLUDING HIGH DIELECTRIC CONSTANT LAYER

摘要

PURPOSE: A method of forming a memory device having a capacitor including a high dielectric constant layer is provided to form a tungsten contact plug of good conductivity connected to a capacitor lower electrode without damaging an alignment key in a memory device using the high dielectric capacitor. CONSTITUTION: A contact hole and a groove for the alignment key are formed in a substrate. A conductive layer is formed to fill the contact hole and cover the inner sidewall of the groove. A capping layer for an oxygen barrier is conformally stacked on the conductive layer. A chemical mechanical polishing(CMP) process is performed to etch the capping layer and the conductive layer so that the contact plug filling the contact hole and the conductive layer and capping layer covering the inner sidewall of the groove are left. A capacitor lower electrode layer is stacked to come in contact with the upper surface of the contact plug. A high dielectric layer is formed on the lower electrode layer. A high temperature oxidation process is performed to crystallize the high dielectric layer.