System and method for measuring dimension of patterns formed on photomask

A system for measuring a dimension of photomasks, comprising:

• a light source emitting a measuring light having a wavelength;
• a transmission detector for receiving the measuring light;
• a stage on which a photomask having circuit patterns is placed, the stage being disposed between the light source and the transmission detector;
• a first optical device disposed between the light source and the stage for causing the measuring light to impinge on the photomask;
• a second optical device disposed between the stage and the transmission detector for causing the measuring light passing through the photomask to impinge on the transmission detector;
• and
• a controller having a dimension-deciding algorithm to determine a dimension of the circuit patterns from a spectroscopic characteristic of the received measuring light, the controller being connected to the transmission detector.

A method for measuring a dimension of a photomask, comprising:

• preparing design data indicating locations of circuit patterns of a photomask;
• fabricating the photomask using the design data;
• transmitting a measuring light having a wavelength through the photomask;
• measuring a spectroscopic characteristic of the transmitted measuring light;
• preparing spectrum-dimension data indicating a relationship between an expected spectroscopic characteristic of the transmitted measuring light and a dimension of the circuit patterns by using the design data;
• and
• comparing the measured spectroscopic characteristic of the transmitted measuring light with the spectrum-dimension data to determine the dimension of the circuit patterns at a region to which the measuring light is transmitted.

A method for measuring a dimension of a photomask, comprising:

• preparing design data indicating locations of circuit patterns of the photomask;
• fabricating the photomask by using the design data;
• splitting a measuring light having a wavelength into a transmitted light transmitted through the photomask and a standard light not transmitted to the photomask;
• comparing intensities of the transmitted light and the standard light to determine a transmissivity of the transmitted light;
• preparing density-dimension data indicating a relationship between density and dimension of the circuit patterns by using the design data;
• preparing spectrum-density data indicating a relationship between an expected transmissivity of the transmitted light and the density of the circuit patterns;
• preparing spectrum-dimension data indicating a relationship between the expected transmissivity of the transmitted light and the dimension of the circuit patterns by using the density-dimension data and the spectrum-density data;
• and
• comparing the transmissivity of the transmitted light with the spectrum-dimension data to determine a dimension of the circuit patterns at a region where the transmitted light is transmitted.