Patent ID: 7157015

Claim:
A method of manufacturing a substrate with a plurality of concave portions, the method comprising the steps of: preparing a substrate; forming a first mask on the substrate; forming a plurality of first initial holes in the first mask by one of a physical method and irradiation with laser beams; forming a plurality of first concave portions in the substrate by subjecting the substrate provided with the first mask having the plurality of first initial holes therein to a first etching process; removing the first mask after the first etching process; forming a second mask on the substrate in which the plurality of first concave portions have already been formed; forming a plurality of second initial holes in the second mask by one of the physical method and irradiation with laser beams; forming a plurality of second concave portions in the substrate by subjecting the substrate provided with the second mask having the plurality of second initial holes therein to a second etching process; and removing the second mask after the second etching process; wherein the plurality of concave portions include the plurality of first concave portions and the plurality of second concave portions.