Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device, comprising:

• forming a resist layer on a semiconductor layer, the resist layer having an opening whose inner wail has an inverse tapered, shape;
• depositing a material layer of a gate electrode having a Ni-containing layer on the resist layer and on the semiconductor layer in the opening;
• depositing a covering layer on the material layer by a sputtering method, the covering layer being any one of a metal which has a melting point equal to or more than 1,600 degrees, and an oxide and a nitride of the metal;
• removing the resist layer to remove the material layer and the covering layer on the resist layer;
• forming an insulating film having a step;
• and
• forming a metal layer on the insulating film.

A semiconductor device comprising:

• a Ni-containing layer;
• an insulating film that covers the Ni-containing layer, and has a step having an upper edge and a lower edge;
• a covering layer that is provided between the Ni-containing layer and the insulating film, and is any one of a metal which has a melting point equal to or more than 1,600 degrees, and an oxide and a nitride of the metal;
• and
• a metal layer that is provided on the lower edge of the step in the insulating layer.