NAME

Physics::Electrodeposition - Model metal electrodeposition (electroplating) on semiconductor wafers.

SYNOPSIS

use Physics::Electrodeposition;

my $ecd = Physics::Electrodeposition->new(
    metal            => 'Copper',
    wafer_diameter   => 300,      # mm
    current_density  => 20,       # mA/cm^2
    target_thickness => 1.0,      # um  (module solves for time)
    efficiency       => 0.97,
    anode_type       => 'soluble',
);

print $ecd->report;               # full text report

my $h  = $ecd->film_thickness_um; # final thickness, um
my $P  = $ecd->power;             # cell power, W
my $mb = $ecd->mass_balance;      # hashref of species moles/grams

DESCRIPTION

Physics::Electrodeposition implements a first-principles engineering model of constant-current (galvanostatic) electrodeposition of a metal onto a circular wafer cathode. It is parameterized for an acid copper-sulfate damascene bath by default but works for any metal/bath by overriding constructor arguments.

The model couples Faraday's law (mass and thickness), a lumped cell-voltage model (thermodynamic + activation + concentration overpotentials + ohmic drop + additive drop) for power, a diffusion-limited current density for transport, and geometry-based estimates of uniformity (Wagner number, seed terminal effect) and surface smoothness.

KEY METHODS

new(%args)

Construct a model. See the source header for the full list of named parameters and their default (copper) values.

film_thickness_um / deposition_rate_um_min / process_time

Growth results from Faraday's law.

mass_deposited / moles_deposited / charge / mass_balance

Chemistry mass balance, including anode reaction, hydrogen side reaction, acid balance, gas evolution, and additive consumption.

cell_voltage / power / energy / specific_energy_kWh_kg

Electrical power model.

limiting_current_density / current_fraction_of_limit / wagner_number / terminal_effect_drop / nonuniformity_percent / roughness_nm / smoothness_verdict

Transport, uniformity and smoothness metrics.

open_fraction / j_applied / j_active / active_area / blanket_equivalent_thickness_um

Through-mask patterning: the open-area fraction from the GDSII mask, the applied (wafer-referenced) and active (in-opening) current densities, the plated area, and the blanket-equivalent thickness for the same charge.

loading_nonuniformity / isolated_to_dense_ratio / feature_aspect_ratio / fill_risk_verdict

Pattern-density (loading) effect on thickness uniformity and feature fill risk.

report

Return a formatted multi-section text report with narrative insight (adds a PHOTORESIST PATTERN section when a GDSII mask is supplied).

PHOTORESIST PATTERNING (GDSII)

Pass gdsii => 'mask.gds' (and usually pattern_layer) to model through-mask plating. The metal then grows only in the resist openings, so the in-opening (active) current density is the applied density divided by the open fraction, features grow 1/open_fraction thicker than a blanket film for the same charge, and pattern-density variation drives a loading (isolated-vs-dense) non-uniformity. See Physics::Electrodeposition::GDSII and Physics::Electrodeposition::Pattern.

UNITS

Public convenience methods report engineering units (um, mA/cm^2, V, W). Internal calculations use cm, A/cm^2, mol/cm^3, s and g.

CAVEATS

The uniformity, roughness, loading and additive-consumption figures are calibrated engineering estimates, not a full 3-D primary/secondary/tertiary current distribution simulation. Use them for scoping and sensitivity studies.

AUTHOR

Generated for the Physics-Electrodeposition project.