Production method for thick film metal electrode and production method for thick film resist

A method for producing a thick film metal electrode having a thickness of 6 μm or more on an upper surface of a circuit element layer formed on a silicon carbide substrate, including:

• a step of treating the upper surface of the circuit element layer with hexamethyldisilazane;
• a step of forming a first positive-negative reverse type resist having a first viscosity on the upper surface of the circuit element layer which is treated with hexamethyldisilazane;
• a step of forming a second positive-negative reverse type resist having a second viscosity, which is larger than the first viscosity, on the first positive-negative reverse type resist such that a total thickness of the first and second positive-negative reverse type resists be 7 μm or more;
• a step of exposing the first and second positive-negative reverse type resists through a mask for exposure including a shading part facing an electrode formation area at which the thick film metal electrode is formed;
• a step of baking the first and second positive-negative reverse type resists to reverse positive properties of the first and second positive-negative reverse type resists to negative properties, after the exposing;
• a step of exposing the whole first and second positive-negative reverse type resists after the baking;
• a step of developing the first and second positive-negative reverse type resists to form an opening, which has a sectional form having an inverse tapered shape and exposes the electrode formation area, after the exposing step for the whole first and second positive-negative reverse type resists;
• a step of post-baking the first and second positive-negative reverse type resists after forming the opening;
• a step of forming a metal film having a thickness of 6 μm or more, which is a base material for the thick film metal electrode by a vapor deposition method from the upper side of the second positive-negative reverse type resist, after the post-baking;
• and
• a step of lifting the first and second positive-negative reverse type resists off.