Method of manufacturing mold substrate for diffraction lattice light guide plate, and method of manufacturing diffraction lattice light guide plate

A method of manufacturing a mold substrate for a diffraction lattice light guide plate, the method comprising:

• preparing a faraday cage with a mesh having a sheet resistance of 0.5 Ω/sq or more provided on an upper surface of the faraday cage;
• providing a sample substrate on a bottom surface of the faraday cage and carrying out flat plasma etching of the sample substrate;
• designating a high etching region inside the faraday cage by examining the sample substrate after etching;
• preparing a support having an inclined surface and positioning a base of the inclined surfacein the high etching region of the faraday cage to align the support;
• providing a substrate for a mold on the inclined surface of the support;
• and
• plasma etching the substrate to simultaneously form a first inclined pattern portion at one side of the substrate and a second inclined pattern portion at the other side of the substrate,
• wherein an etch rate of the patterning decreases and then reversely increases from an upper region to a lower region of the inclined surface,
• wherein the first inclined pattern portion includes a first inclined recess pattern having a depth gradient, and
• wherein the second inclined pattern portion includes a second inclined recess pattern having a depth difference of 0 nm to 50 nm.