Measuring apparatus and substrate analysis method using the same

A measuring apparatus, comprising:

• a light source that generates a laser beam having a first pulse;
• a beam splitter that splits the laser beam into a probe laser beam and a reference laser beam;
• an antenna that receives the probe laser beam to produce a terahertz beam and provides a target object with the terahertz beam to generate a second pulse different from the first pulse;
• a pulse stretcher that stretches a width of the first pulse of the reference laser beam;
• a wave plate that receives the reference laser beam to create a vertical polarization component and a horizontal polarization component of the reference laser beam;
• an electro-optical device that receives the reference laser beam and the terahertz beam to change a pulse of the vertical polarization component and a pulse of the horizontal polarization component based on the second pulse of the terahertz beam;
• and
• a streak camera that detects the vertical polarization component and the horizontal polarization component to obtain a time-domain signal corresponding to a ratio between the pulse of the vertical polarization component and the pulse of the horizontal polarization component.

A substrate analysis method, comprising:

• obtaining a time-domain signal using a terahertz beam transmitted from a substrate and a femtosecond laser beam that temporally and spatially overlaps the terahertz beam;
• performing a Fourier transform on the time-domain signal to calculate real and imaginary spectra;
• analyzing the real and imaginary spectra to obtain first to nth real and imaginary spectra of first to nth layers included in the substrate;
• and
• using the first to nth real and imaginary spectra to calculate electrical characteristics of the first to nth layers.