A break pattern is formed on a silicon wafer using an anisotropic etching process. The break pattern includes a plurality of through holes, each of having a first plane perpendicular to a plane defined by the silicon wafer, a second plane opposite to the first plane, a third plane that is perpendicular to the plane of the silicon wafer and intersects the first plane at an acute angle, and a fourth plane that is opposite to the third plane, is perpendicular to the plane of the silicon wafer, and intersects the second plane at an acute angle. The anisotropic etching is performed using a mask pattern having a predetermined shape to form, around the break pattern, a thin portion that has a smaller thickness than other portions of the silicon wafer. The silicon wafer is then divided into a plurality of silicon substrates along the break pattern.