Substrate having a mark formed on a surface thereof by a CO2 laser beam

The present invention relates to a CO2 laser-transparent material having a mark on the surface thereof and the method for making the same. The method includes the following steps: providing a first substrate, which has a top surface and a bottom surface; providing a second substrate which has a top surface; putting the bottom surface of the first substrate on the top surface of the second substrate; irradiating a CO2 laser beam to the top surface of the second substrate by passing through the top surface and the bottom surface of the first substrate;