Method for manufacturing semiconductor device

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

• forming a mesa on a front surface of a semiconductor substrate;
• forming a lower layer resist soluble in a developer, to cover the front surface and the mesa;
• forming an upper layer resist in which a sensitised region is soluble in a developer, to cover the lower layer resist;
• forming a sensitised portion by sensitising a region of the upper layer resist covering at least the mesa in a width direction of the mesa as viewed from a direction perpendicular to the front surface;
• exposing an upper surface of the mesa by removing the sensitised portion and a part of the lower layer resist by using a developer;
• forming a metal layer on the mesa, on the upper layer resist, and on a region in contact with at least the mesa, of a surface of the lower layer resist exposed when exposing the upper surface of the mesa;
• and
• removing portions of the metal layer on the upper layer resist and the lower layer resist, the upper layer resist, and the lower layer resist.