Liquid ejection head and method for producing the same

A method for producing a liquid ejection head including a substrate having an energy-generating device configured to generate energy used for ejecting a liquid from an orifice;

• a transparent channel wall member forming an inner wall of a channel leading to the orifice;
• and an intermediate layer disposed between and in contact with a surface of the substrate and the channel wall member and having a refractive index different from a refractive index of the channel wall member;
• the method comprising the steps of:
• preparing a substrate having a surface on which an intermediate material layer used for forming the intermediate layer and a mask material layer used as a mask for etching the intermediate material layer are disposed in the stated order;
• forming a mask from the mask material layer, the mask having a third outer end surface forming contours of a symbol as viewed in a direction from above the mask toward the substrate and making a third angle with the surface of the substrate and a fourth outer end surface facing a region corresponding to the channel and making a fourth angle with the surface of the substrate, the third angle being an obtuse angle, the fourth angle being smaller than the third angle;
• and
• etching the intermediate material layer using the mask to form an intermediate layer having a first outer end surface forming the contours of the symbol and making a first angle with the surface of the substrate and a second outer end surface facing the channel and making a second angle with the surface of the substrate, the first angle being an obtuse angle, the second angle being smaller than the first angle.