Method of forming film on substrate and method of manufacturing liquid ejection head

A method of manufacturing a liquid ejection head including:

• a substrate having a first surface and a second surface on a side opposite to the first surface;
• a liquid supply port through which the first surface and second surface of the substrate communicate with each other;
• a liquid resistant protective film at least continuous to an inner wall of the liquid supply port and to a part of the first surface;
• and a member configured to define, on the first surface, a liquid bubble forming chamber in which energy for ejecting a liquid is generated and a liquid flow path along which a liquid is transported from the liquid supply port to the liquid bubble forming chamber,
• the method comprising:
• forming a protective member in a region that is a part of the first surface and that contains a region in which the liquid supply port is opened;
• after the forming of the protective member, disposing an organic structure from a resin on the first surface at a distance from the protective member, the organic structure being at least a part of the member configured to define the liquid bubble forming chamber and the liquid flow path;
• forming the liquid supply port in the substrate;
• removing the protective member;
• forming the liquid resistant protective film by CVD on the inner wall of the liquid supply port and a region in which the protective member is removed;
• and
• patterning so as to leave the liquid resistant protective film formed on the first surface in the region in which the protective member is removed.