Method of notching brittle material, method of making member having notch, and method of making display device

A method of notching a brittle material, the method comprising:

• heating the brittle material by forming a light beam spot on a predetermined face of the brittle material by irradiating an area of the predetermined face with a light beam;
• and
• forming a notch in the brittle material by exfoliating a fraction of the brittle material including the area from the brittle material by cooling a portion of the brittle material including the area after the heating the brittle material,
• wherein a length of the area in a longitudinal direction of the predetermined face is smaller than a total length of the predetermined face in the longitudinal direction, and a length of the light beam spot in a lateral direction of the predetermined face is equal to a total length of the predetermined face in the lateral direction.