SEMICONDUCTOR DEVICE WITH DUAL POLYSILICON GATE TO PREVENT POLYSILICON DEPLETION EFFECT AND METHOD FOR MANUFACTURING THE SAME

摘要

A semiconductor device with a dual polysilicon gate and its manufacturing method are provided to improve the reliability of the device by preventing the outdiffusion of dopants of a silicon electrode due to the following gate re-oxidation using an oxidation barrier made of a nitride layer. A semiconductor device includes a semiconductor substrate(31), a gate oxide layer(33) on the semiconductor substrate, a silicon electrode, a metal electrode and a gate hard mask, an oxidation barrier, and an oxide layer. The silicon electrode is formed on the gate oxide layer. The silicon electrode is implanted with predetermined ions. The metal electrode and the gate hard mask(38) are stacked on the silicon electrode. The oxidation barrier is formed at a first sidewall of the metal electrode. The oxide layer(41) is formed at a second sidewall of the silicon electrode. The oxidation barrier is formed by performing selectively a nitridation process on the metal electrode.