TW266324B - Process for dynamic random access memory with coaxial capacitor - Google Patents

Abstract

A process of dynamic random access memory with coaxial capacitor comprises the steps of: forming field oxide needed by separating active regions; forming field effect transistor which has gate dielectric, gate electrode, spacer and source/drain region; depositing insulator-1, insulator-2 and insulator-3; depositing one doped polysilicon-1; depositing insulator-4; forming node contact by lithography and etching; depositing one doped polysilicon-2 which will fill up the above node contact; anisotropically performing etchback to the above polysilicon-2 by plasma etching in order to form polysilicon plug in the above node contact; removing the above insulator-4 by chemical solution; depositing insulator-5; anisotropically performing etchback to the above insulator-5 by plasma etching in order to form spacer on the sides of the above polysilicon plug; depositing one doped polysilicon-3; anisotropically performing etchback to the above polysilicon-3 by plasma etching in order to form spacer, and the above etchback stops on surface of the above insulator-3; removing the above spacer formed by insulator-5 by chemical solution, completing storage node of capacitor; forming one very thin capacitor dielectric; forming one doped polysilicon-4, and defining top plate of capacitor by lithography and etching.