lsOxidationPresets.hpp

Go to the documentation of this file.

#pragma once
 
#include <lsOxidationModel.hpp>
 
namespace viennals {

struct OxidationPresets {
  static OxidationParameters wet1000CDealGrove100() {
    OxidationParameters params;
    params.diffusionCoefficient = 0.157; // µm²/hr, B/2 = D_eff
    params.reactionRate = 0.74;          // µm/hr, B/A = k_s
    params.transferCoefficient = 100.;   // large → surface conc. ≈ C*
    params.equilibriumConcentration = 1.;
    params.oxidantMoleculeDensity = 1.;
    params.expansionCoefficient = 2.27;         // SiO2/Si volume ratio
    params.temperature = 1273.15;               // 1000 °C in K
    params.reactionActivationVolume = 1.76e-35; // m³, stress activation for k_s
    params.diffusionActivationVolume = 0.;
    return params;
  }

  static OxidationDeformationParameters oxideMechanics1000C(double timeStep) {
    OxidationDeformationParameters params;
    params.viscosity = 1.e10;              // Pa·hr, effective oxide viscosity
    params.shearModulus = 3.e10;           // Pa
    params.shearActivationVolume = 3.e-28; // m^3 (300 A^3)
    params.stressTimeStep = timeStep;
    return params;
  }

  static OxidationMaskParameters siliconNitrideMask(double temperatureCelsius) {
    static constexpr double table[4][3] = {
        // °C, eta_N (Pa hr = P / 10 / 3600), V_N (m^3)
        {800., 6.0e16 / 36000., 120e-30},
        {900., 3.1e16 / 36000., 130e-30},
        {1000., 5.0e15 / 36000., 170e-30},
        {1100., 1.1e15 / 36000., 350e-30}};
    const double inverse = 1. / (temperatureCelsius + 273.15);
    int k = 0; // segment [k, k + 1]
    while (k < 2 && temperatureCelsius > table[k + 1][0])
      ++k;
    const double i0 = 1. / (table[k][0] + 273.15);
    const double i1 = 1. / (table[k + 1][0] + 273.15);
    const double w = (inverse - i0) / (i1 - i0);
    const double wT = std::clamp((temperatureCelsius - table[k][0]) /
                                     (table[k + 1][0] - table[k][0]),
                                 0., 1.);
    OxidationMaskParameters params;
    params.youngModulus = 270e9; // Pa
    params.poissonRatio = 0.27;
    params.viscosity = std::exp((1. - w) * std::log(table[k][1]) +
                                w * std::log(table[k + 1][1]));
    params.shearActivationVolume =
        (1. - wT) * table[k][2] + wT * table[k + 1][2];
    return params;
  }
  static OxidationMaskParameters siliconNitrideMask1000C() {
    return siliconNitrideMask(1000.);
  }
};
 
} // namespace viennals