Diode layer stack flip-chip mounted to a leadframe by use of a copper nickel tin metallization stack and diffusion soldering

A method for fabricating a semiconductor device, the method comprising:

• providing a diode layer stack comprising:
• a silicon carbide diode die comprising a first main surface at an anode side of the diode die and a second main surface opposite to the first main surface at a cathode side of the diode die,
• a layer stack on the first main surface of the diode die, the layer stack comprising a copper layer disposed on the first main surface of the diode die, and a tin or indium containing layer disposed above the copper layer;
• providing a die pad comprising a copper leadframe comprising a first main surface and a second main surface opposite to the first main surface;
• and
• performing a diffusion soldering process for connecting the diode layer stack with the layer stack to the first main surface of the die pad,
• wherein the diffusion soldering process forms an intermetallic compound from the copper layer and the tin or indium containing layer.