Finite element simulation for ultraviolet excimer laser processing of patterned Si/SiGe/Si(100) heterostructures

Abstract

Ultraviolet (UV) Excimer laser assisted processing is an alternative strategy for producing patterned silicon germanium heterostructures. We numerically analyzed the effects caused by pulsed 193 Excimer laser radiation impinging on patterned amorphous hydrogenated silicon (a-Si:H) and germanium (a-Ge:H) bilayers deposited on a crystalline silicon substrate [Si(100)]. The proposed two dimensional axisymmetric numerical model allowed us to estimate the temperature and concentration gradients caused by the laser induced rapid melting and solidification processes. Energy density dependence of maximum melting depth and melting time evolution as well as three dimensional temperature and element distribution have been simulated and compared with experimentally obtained results.

Laser synthesis of germanium tin alloys on virtual germanium

“…Finally, Raman analysis using a 632.8 nm excitation source in backscattering configuration has been performed to confirm the composition and crystalline structure of the alloy [11][12][13] by analyzing the frequency shift, given by composition and strain variation. 18 The vibrational modes of fully strained and relaxed GeSn alloys 19,20 show a decreasing GeGe phonon frequency and an increasing peak asymmetry with increasing Sn concentration.…”

“…The melting depth and duration were calculated using a finite element method (FEM) solution of the heat conduction differential equation (HCDE). 13 The direct relation between experiment and theory was provided by the liquid phase duration that was both calculated through FEM and extracted from the TRR experimental data. Figure 1 compares the temporal evolution of the sample reflectivity, induced by the first 200 mJ/cm 2 laser pulse, with the maximum melting depth (MMD) and interface (Sn/v-Ge and v-Ge/Si) temperature, as estimated by FEM.…”

A Review of Simulation Methods of Laser Matter Interactions Focused on Nanosecond Laser Pulsed Systems

“…Researchers have studied this transformation using numerical methods. [72][73][74][75][76][77] O. García et al 77 have investigated both experimentally and by means of a finite element simulation the a-Si local crystallization irradiated by a single nanosecond laser pulse. Different energy regimes were taken into account in order to evaluate the effect of the laser fluence on the a-Si crystallization.…”

Study of dopant activation in biaxially compressively strained SiGe layers using excimer laser annealing

“…The model considers the temperature dependence of density q (g/cm 3 ), thermal conductivity k (W/cm 2 K), and specific heat C (J/gK). 20 The implementation of the temporal and spatial distribution of the laser pulses, I 0 (W/cm 2 ), provided by the Excimer laser, is successfully fitted by the following mathematical expression: 19 I 0 ðr; tÞ ¼ U½F; f ðsÞ ½1 À Rðn; jÞ exp½Àay ;…”