Developing Industry-Level Terahertz Imaging Resolution Using Mathematical Model

High-quality terahertz (THz) images are vital for the application of THz imaging in integrated circuit (IC) manufacturing. In far-field imaging, the primary reason for the blurring of the reconstructed THz images is the attenuation of the high-frequency components and Fraunhofer diffraction. This attenuation is almost due to the properties of the THz Gaussian beam and frequency absorption in the medium. The Fraunhofer diffraction is the primary reason why the images undergo blurring in any frequency regime. We propose a mathematical model to develop the resolution of THz images. The proposed model is based on the THz absorption variate. The Gaussian distribution of the THz beam is considered by including the numerical aperture of the THz time-domain spectroscopy system, spot radius at the THz beam waist, beam wavelength, and distance of the waist from the target into the model. Thus, the proposed model is useful for restructuring the THz images and developing the resolution of THz images in industrial applications.