Junction & Carrier Metrology

Electron Beam Induced Current (EBIC) Lab

Model carrier generation, minority diffusion lengths (L_d), p-n junction electric field collection, defect contrast, and fab tool DCF economics.

← Cathodoluminescence Lab All Simulations →

1. Device & Junction Presets

Sub-micron minority hole diffusion length L_p profiling across vertical GaN power drift layers to optimize reverse blocking and surge current.

2. Beam & Transport Parameters

10.0 keV
200 pA
380 nm
140 nm
30 cm²/Vs
22%

3. EBIC Nanoprober Suite Financials

$780k
$2.15M
Peak EBIC
22.8 nA
Generation Rate
1.62e+11 s⁻¹
Diffusion Length
380 nm
Carrier Lifetime
1.86 ns
Collection Efficiency
88%
Diff. Coeff (D)
0.78 cm²/s
20-Year Fab NPV
+$18.42M
Internal Rate (IRR)
51.2%

Interactive Physics Visualizers

EBIC Current Line Scan Profile I(x) Across p-n Junction SCR Plateau & Diffusion Decay
2D Nanoscale EBIC Current Map (2.0 µm × 2.0 µm Field of View) Junction & Dislocation Contrast
Logarithmic Extraction: ln[I_EBIC · (x - x_j)^0.5] vs Distance Slope = -1 / L_d

20-Year SEM-EBIC Metrology Suite Cash Flow & DCF Schedule

Model instrument CapEx, nanoprober maintenance ($70k/yr), 8.5% discount rate, 21% tax, and net cash flow generated through power device and solar cell excursion prevention.

Period Yield Benefit OpEx Deprec. Free Cash Flow Discounted FCF Cumulative FCF

Formative Knowledge Check

1. What generates the external current in an Electron Beam Induced Current (EBIC) measurement without any external applied bias?

2. In an EBIC line scan across a cross-section, how is minority carrier diffusion length (L_d) extracted from the current decay away from the junction?

3. Why do threading dislocations appear as dark lines or spots in EBIC maps?

Comprehensive Technical Guide: Electron Beam Induced Current

Physics of Charge Generation & Collection

Electron Beam Induced Current (EBIC) probes active electronic junctions with nanoscale spatial resolution. High-energy primary electrons generate electron-hole pairs at rate G:

G = [I_b · V_b · (1 - η_BSE)] / [q_e · E_eh]  |  E_eh ≈ 2.8 E_g + 0.6 eV

Within the space charge region (SCR), carrier collection efficiency approaches 100%, yielding a current plateau. Outside the SCR, carriers must diffuse to the junction edge before recombining.

Diffusion Length & Defect Recombination

The spatial profile of collected current away from the junction edge follows:

  • Diffusion Length Decay: I_EBIC(x) ∝ x^(-α) · exp(-|x - x_j| / L_d), where L_d = √(D · τ).
  • Surface Recombination Effect: Parameter α ranges from 0.5 (infinite surface recombination velocity v_s) to 1.5 (negligible surface recombination).
  • Defect Contrast: c = (I₀ - I_d) / I₀ directly quantifies the recombination strength of individual threading dislocations and grain boundaries.

Frequently Asked Questions (FAQ)

Electron Beam Induced Current (EBIC) is a scanning electron microscopy technique that measures internal electrical activity in semiconductor devices. When the focused electron beam injects electron-hole pairs near a p-n junction, Schottky barrier, or heterojunction, the built-in electric field in the space charge region (SCR) separates the carriers before they recombine. Connecting the junction contacts to an external low-noise transimpedance amplifier records a current I_EBIC that maps junction location, depletion layer width, and carrier collection efficiency.

When the electron beam scans across a cleaved cross-section perpendicular to a junction, carriers generated in neutral regions must diffuse to the space charge region edge to be collected. The collected current decays exponentially with distance x from the junction: I_EBIC(x) ∝ x^(-α) · exp(-x / L_d), where α accounts for surface recombination. Plotting ln[I_EBIC · x^α] versus distance yields a linear slope equal to -1/L_d, allowing direct measurement of minority hole (L_p) or electron (L_n) diffusion lengths from 50 nm to over 100 microns.

Dislocations, grain boundaries, and point defect clusters contain high densities of midgap states that accelerate non-radiative Shockley-Read-Hall (SRH) recombination. When the primary electron beam strikes a defect, excess carriers recombine locally rather than diffusing to the junction, causing a drop in collected external current. The resulting defect contrast c = (I₀ - I_d) / I₀ directly measures the localized recombination strength and electrical activity of individual defect lines.

In vertical GaN and SiC power diodes and MOSFETs, managing high reverse breakdown voltages requires junction termination extensions (JTE) and guard rings to relieve electric field crowding. EBIC imaging visualizes the lateral expansion of the space charge region under reverse bias, identifying premature punch-through, non-uniform doping activation, and micro-plasma hotspots before devices undergo packaging.

An SEM-based EBIC nanoprober system equipped with sub-picoamp current preamplifiers costs between $650k and $880k with annual maintenance of approximately $70k. In power semiconductor, optoelectronic, and solar cell manufacturing, EBIC screens breakdown hotspots and carrier lifetime degradation, preventing yield excursions and field warranty claims valued at $1.85M to $2.45M annually. Under an 8.5% discount rate and 21% corporate tax, investments achieve a discounted payback period of 1.6 to 1.9 years, an IRR of 44% to 58%, and a 20-year cumulative net present value (NPV) exceeding $17M.

Related Semiconductor & Carrier Metrology Simulations

Cathodoluminescence Lab

Model electron-beam excitation, sub-50nm hyperspectral emission, and dislocation dark spots.

DLTS Defect Spectroscopy Lab

Model deep-level trap emission kinetics, rate-window boxcar deconvolution, and power fab DCF.

TRPL & Photoluminescence Lab

Model optical bandgap emission, ABC recombination kinetics, and biexponential carrier lifetimes.

Atom Probe Tomography Lab

Model 3D atomic needle reconstruction, field evaporation, ToF mass spectrometry, and LEAP tool DCF.

KPFM Surface Potential Lab

Probe nanoscale contact potential differences, local work functions, and trapped surface charge.

All Business Simulations Directory

Browse over 900 business simulations, financial models, engineering calculators, and interactive laboratories.