KAJIAN PEMODELAN KONSTANTA DIELEKTRIK GRAPHENE HASIL SPECTROSCOPY ELLIPSOMETRY MENGGUNAKAN METODE INVERSI NUMERIK NEWTON-RAPHSON; STUDY OF GRAPHENE DIELECTRIC CONSTANT MODELING OF SPECTROSCOPY ELLIPSOMETRY RESULT USING NEWTON-RAPHSON NUMERICAL INVERSION METHOD

Ariasoca, Thomas Aquino, Imam Santoso

2016 | Skripsi | FMIPA

Study of the modeling of the Graphene dielectric constant of spectroscopy ellipsometry result using Newton-Raphson inversion method has been done. In this research, the values of dielectric constant are obtained by invert the ? and ? value of spectroscopy ellipsometry result using Newton-Raphson method. The initial value guess of Newton-Raphson method for each data point are made different to overcome the 180-? phase reversal in the ? data of SiO2 / Si substrate and Graphene / SiO2 / Si system which previously predicted to make Newton-Raphson method failed to reach convergence. The results show that changes in the value of the second absorption peak in the imaginary part of the dielectric constant of silicon are predicted due to the surface roughness, and the calculation of the dielectric constant and the refractive index of graphene on the substrate SiO2 / Si by the method of Newton Raphson can be done using ? and ? values that have been calculated using previously known results of graphene dielectric constant values. The ? and ? values from experimental results have not been able to generate the expected value of the dielectric constant of graphene because we predict that the ? and ? value is derived from the different value of physical parameter or different real optical model.

Kata Kunci : graphene; spectroscopy ellipsometry; numerical inversion, Newton- Raphson method