viennals::OxidationMaskTracker< T, D > Class Template Reference

Unified oxidation time-step orchestrator. More...

#include <lsOxidation.hpp>

Public Member Functions
	OxidationMaskTracker (SmartPointer< Domain< T, D > > mask)
bool	tracks (const SmartPointer< Domain< T, D > > &mask) const
	False for another mask, or after the mask was resampled to another grid.
template<class VelocityFunction>
void	correct (SmartPointer< Domain< T, D > > mask, VelocityFunction &&velocity, T dt)
	Re-sample the just advected mask: dt is the advection time, velocity (Vec3D<T>(const Vec3D<T> &coordinate)) the one it was advected with.

Detailed Description

template<class T, int D>
class viennals::OxidationMaskTracker< T, D >

Unified oxidation time-step orchestrator.

Couples diffusion and viscoelastic deformation into a single CFL-limited step. When a mask interface is provided the solver operates in LOCOS mode; without one it performs standard planar or step oxidation.

Standard mode (no mask):

1. Diffusion+deformation coupled solve (OxidationModel)
2. Ambient interface advection (deformation velocity)
3. Si/SiO2 reaction interface advection (diffusion velocity)
4. Interior fill for warm-start persistence

LOCOS mode (mask provided):

1. Diffusion+deformation coupled solve (OxidationModel); the nitride joins the deformation solve as an elastic body, creeping when OxidationMaskParameters sets a viscosity (monolithic oxide + nitride mechanics)
2. Pre-advection boolean clip (ambientInterface \ maskInterface)
3. Ambient interface advection (oxide velocity)
4. Si/SiO2 reaction interface advection (diffusion velocity)
5. Mask advection (nitride velocity), re-sampled from the mask's shape at the start of the call and the nitride displacement (OxidationMaskTracker: keeps its corners sharp)
6. Interior fills + post-advection boolean clip With setMaskBarrierOnly(true) the mask is a diffusion barrier only: it is withheld from the mechanics and carried along by the oxide.

Usage (standard):

auto ox = ls::Oxidation<double, 2>::New(si, ambient);
ox->setOxidationParameters(oxParams);
ox->setDeformationParameters(defParams);
ox->apply(0.1);  // advection time in hours

Usage (LOCOS):

auto ox = ls::Oxidation<double, 2>::New(si, ambient, mask);
ox->setOxidationParameters(oxParams);
ox->setDeformationParameters(defParams);
ox->setMaskParameters(maskParams);
ox->setSolveBounds(minIdx, maxIdx);
ox->applyCFLLimited(0.35, 0.499);
ox->getDiffusionField()->getConcentration(pt);  // diagnostics

Lagrangian nitride surface. The nitride is an elastic solid that moves almost rigidly, by up to hundreds of nm, and level-set advection rounds its convex corners by a numerical diffusion that grows with the distance travelled, for every scheme order: over a 0.1 um lift on a 5 nm grid the side wall 2.5 nm from a corner moved in by 13 nm (Engquist-Osher 1st order) or 6.5 nm (WENO5 + RK3), and a 50 nm strip lost its contact with the oxide. After each advection the mask is therefore re-sampled from the shape it had when the tracker was created and the accumulated displacement u of the nitride, phi(x) = phi_0(x - u(x)) (D-linear in phi_0). u follows the material: u(x) = u_old(x - v dt) + v dt with the velocity v the mask was advected with (accumulating v at a fixed point instead turns a rotation of angle a by an error ~ a^2 r / 2). The advection still moves the narrow band and carries the point data; the re-sampled band is normalised like an advected one. A tracker lives for one Oxidation object, i.e. one process call: phi_0 is sampled once per call (over a 0.1 um lift the corner moved by 0.9 nm in one call, 2.5 nm in six; re-sampled every step, 17 nm).

Constructor & Destructor Documentation

OxidationMaskTracker()

template<class T, int D>

viennals::OxidationMaskTracker< T, D >::OxidationMaskTracker ( SmartPointer< Domain< T, D > > mask )

inlineexplicit

Member Function Documentation

correct()

template<class T, int D>

template<class VelocityFunction>

void viennals::OxidationMaskTracker< T, D >::correct ( SmartPointer< Domain< T, D > > mask, VelocityFunction && velocity, T dt )

inline

Re-sample the just advected mask: dt is the advection time, velocity (Vec3D<T>(const Vec3D<T> &coordinate)) the one it was advected with.

tracks()

template<class T, int D>

bool viennals::OxidationMaskTracker< T, D >::tracks ( const SmartPointer< Domain< T, D > > & mask ) const

inline

False for another mask, or after the mask was resampled to another grid.

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The documentation for this class was generated from the following file:

• include/viennals/lsOxidation.hpp