Numerical investigation of linear and nonlinear Photothermal Radiometry on silicon wafers using a chebyshev spectral method

In the present work we examine the Photothermal Radiometric (PTR) Signal from silicon wafers subject to a modulated light source. The stationary one-dimensional equations are solved numerically using a Galerkin Spectral Method. Shifted Chebyshev Polynomials are used as basis functions and the mixed boundary conditions are imposed via bordering. The scheme's overall convergence and accuracy are verified. Both the linear and nonlinear models are considered and the results confirm the predictions of the physical theory, regarding the dependence of the PTR signal on the governing parameters.