Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device, comprising:

• forming a first conductive film over a semiconductor layer;
• forming a second conductive film over the first conductive film;
• performing first treatment to form a first layer on a top surface of the second conductive film;
• etching the first layer and the second conductive film to expose a side surface of the second conductive film;
• performing second treatment to form a second layer on the side surface of the second conductive film;
• and
• etching the first conductive film to expose a side surface of the first conductive film and part of a top surface of the semiconductor layer,
• wherein the first treatment and the second treatment each comprise exposing a surface of the second conductive film to an atmosphere containing silane and then performing plasma treatment in an atmosphere containing nitrogen.

A method for manufacturing a semiconductor device, comprising:

• forming a first conductive film over a semiconductor layer;
• forming a second conductive film over the first conductive film;
• etching the second conductive film to expose a side surface of the second conductive film;
• performing first treatment to form a first layer on a top surface of the second conductive film and a second layer on the side surface of the second conductive film;
• and
• etching the first conductive film,
• wherein the first treatment comprises exposing a surface of the second conductive film to an atmosphere containing silane and then performing plasma treatment in an atmosphere containing nitrogen.