MANUFACTURING METHOD OF VERTICAL GaN-BASED SEMICONDUCTOR DEVICE AND VERTICAL GaN-BASED SEMICONDUCTOR DEVICE

A manufacturing method of a vertical GaN-based semiconductor device, the vertical GaN-based semiconductor device comprising:

• a GaN-based semiconductor substrate;
• a GaN-based semiconductor layer including a drift region having doping concentration of an n type impurity lower than that of the GaN-based semiconductor substrate, and is provided on the GaN-based semiconductor substrate;
• and
• MIS structure having the GaN-based semiconductor layer, an insulating film contacting the GaN-based semiconductor layer, and a conductive portion contacting the insulating film, the method includes:
• forming the MIS structure,
• implanting an n type dopant in a back surface of the GaN-based semiconductor substrate after the forming of the MIS structure, and
• annealing the GaN-based semiconductor substrate after the implanting of the n type dopant.