Method for forming gate electrode of flash memory

Abstract

The present invention discloses a method for forming a gate electrode of a flash memory. A tunnel oxide film is formed on the whole surface of a semiconductor substrate. A conductive film of a floating gate is formed over the resultant structure. A gate insulation film is formed by depositing a TaON film on the conductive film for the floating gate. A conductive film for a control gate is formed on the gates insulation film. The conductive film for the control gate, the gates insulation film, the conductive film for the floating gate and the tunnel oxide film are patterned according to a photolithography process using a gate mask, thereby forming a gate electrode. Thus, the TaON film having a high dielectric constant and a stabilized bonding structure is used as the insulation material between the floating gate and the control gate. As a result, an oxidization reactivity with the floating gate is reduced, and a thickness of an equivalent oxide film is decreased, thereby obtaining a high capacitance.

Dependencies are inferred from the claim text.