Patent ID: 8241510

Claim:
A method for producing an inkjet recording head including a substrate having a first surface and a second surface opposite the first surface, the substrate being provided with an energy-generating element at the first surface side, the energy-generating element being configured to generate energy utilized for discharging ink, and the head including a supply port configured to supply ink, the supply port passing from the first surface to the second surface of the substrate, the method comprising: forming a first protective layer at the second surface side of the substrate; forming a through hole to be formed into a supply port in the substrate by reactive ion etching, the through hole having openings on the first surface and the second surface, the substrate having the first protective layer disposed on the second surface, the first protective layer having an overhang extending into the region of the opening on the second surface; forming a second protective layer so as to continuously cover the overhang of the first protective layer and an inner wall from the first surface to the second surface; and removing a portion of the second protective layer at the first surface side and corresponding to the opening on the first protective layer in such a way that a portion of the second protective layer to cover the inner wall of the through hole remains.