Method of forming a capacitor for a semiconductor memory device

Abstract

Disclosed is a method of forming a capacitor for a semiconductor memory device according to the present invention. The method includes the steps of: forming a lower electrode on a semiconductor substrate; performing a surface-treatment process to prevent a natural oxide layer from generating on the surface of the lower electrode; forming a TaON layer on the upper part of the surface-treated lower electrode by a reaction of Ta chemical vapor, O,gas and NH,gas; crystallizing the TaON layer; and forming an upper electrode on the upper part of the TaON layer, wherein the TaON layer is formed in a low pressure chemical vapor deposition (LPCVD) chamber equipped with a shower head injecting Ta chemical vapor, O,gas and NH,gas on an upper part thereof and at a temperature of 300 to 600° C. with pressure of 0.1 to 10 Torr; wherein the TaON layer is formed in the LPCVD chamber that a first injector to which Ta chemical vapor and O,gas are injected and formed at one side-wall of the TaON layer and a second injector to which NH,gas is injected and formed at the other side-wall opposed to the first injector, thereby injecting reaction gases in a counter-flow state, and the TaON layer is formed at a temperature of 300 to 600° C. with pressure of 0.1 to 10 Torr; wherein the TaON layer is formed in the LPCVD chamber that a first injector to which Ta chemical vapor and O,gas are injected and formed at one side-wall of the TaON layer and a second injector to which NH,gas is injected and formed at the other side-wall opposed to the first injector, thereby injecting reaction gases in a counter-flow state, and the TaON layer is formed at a temperature of 300 to 600° C. with pressure of 0.1 to 10 Torr.