United Microelectronics Corp.

Gin-Chen Huang

Yu-Ren Wang

Chien-Liang Lin

Tsuo-Wen Lu

Ying-Wei Yen

Shao-Wei Wang

A method for forming a gate structure includes the following steps. A substrate is provided. A silicon oxide layer is formed on the substrate. A decoupled plasma-nitridation process is applied to the silicon oxide layer so as to form a silicon oxynitride layer. A first polysilicon layer is formed on the silicon oxynitride layer. A thermal process is applied to the silicon oxynitride layer having the first polysilicon layer. After the thermal process, a second polysilicon layer is formed on the first polysilicon layer. The first polysilicon layer can protect the gate dielectric layer during the thermal process. The nitrogen atoms inside the gate dielectric layer do not lose out of the gate dielectric layer. Thus, the out-gassing phenomenon can be avoided, and a dielectric constant of the gate dielectric layer can not be changed, thereby increasing the reliability of the gate structure.

Gate structure and a method for forming the same

A gate structure and a method for fabricating the same are described. A substrate is provided, and a gate dielectric layer is formed on the substrate. The formation of the gate dielectric layer includes depositing a silicon nitride layer on the substrate by simultaneously introducing a nitrogen-containing gas and a silicon-containing gas. A gate is formed on the gate dielectric layer, so as to form the gate structure.

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Taipei County, Taiwan

Gin-Chen Huang