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Abstract

Examines silicon thermal oxidation using Deal-Grove modeling and a controlled laboratory run. Arrhenius analysis extracted activation energies from simulated growth data at multiple temperatures. A silicon wafer was thermally oxidized at 1000°C; oxide thickness was estimated by color comparison and characterized via SEM and AFM.

TOPSOIL

Simulation Setup

  • Used NanoHub Process Lab: Oxidation tool to generate Deal-Grove growth datasets
  • Parameters: Dry oxidation, 1200 min (20 hrs), initial thickness 30 nm, temperatures 900/1000/1100/1200°C, 2 atm pressure, Si(100)
  • Extracted rate constants for Arrhenius analysis

Arrhenius Analysis

Plotted ln(rate constant) vs. 1/T (reciprocal absolute temperature).

  • B/A (linear rate constant): surface reaction limited
  • B (parabolic rate constant): diffusion limited
Arrhenius plot for B (parabolic rate constant)
Arrhenius plot for B (parabolic rate constant)
Arrhenius plot for B/A (linear rate constant)
Arrhenius plot for B/A (linear rate constant)

Activation energies were extracted by multiplying the negative slope by Boltzmann's constant. Extracted values compared favorably to literature, particularly for the diffusion-limited (B) regime.

Experimental Procedure

  • Placed Si(100) wafer face-up in Thermo Scientific Lindberg Blue M box furnace
  • Set 1000°C for ~20 hours
  • Shut off and allowed several hours to cool; removed below 30°C
  • Note: No O₂ or H₂O gas was introduced; growth relied on residual ambient oxidants

Equipment

EquipmentDetails
Silicon waferPolished, Si(001)
FurnaceThermo Scientific Lindberg Blue M
SEMTescan Mira 3
AFMPark Systems NX10

Visual Examination

After oxidation, the wafer showed hues of carnation pink and red-violet under light. Using standard oxide color charts, these map to ~4200–6000 Å. The Deal-Grove simulation at 1000°C for 20 hours in dry O₂ predicted ~5600 Å. Because no O₂ was introduced during the actual run, growth was slower; the experimental thickness of ~4200 Å is consistent with ambient oxidation kinetics.

Oxidized silicon wafer showing interference color
Oxidized wafer showing carnation pink and red-violet hues under white light

SEM and AFM Results

SEM of wafer edge cross-section post-oxidation
SEM of wafer edge cross-section post-oxidation
AFM of surface morphology after oxidation
AFM of surface morphology after oxidation

Conclusions & Future Work

The work demonstrated silicon oxidation behavior and provided hands-on experience linking Deal-Grove simulation to experiment. The sensitivity of the model to boundary conditions (gas flow, pressure, initial thickness) was clear from the divergence between simulated and experimental results.

Future iterations:

  • Clean samples between steps (ultrasonic IPA + DI water) before imaging
  • Follow defined dry/wet oxidation parameters with proper gas introduction
  • Run multiple temperature points experimentally to build a real Arrhenius plot from measured data
Thanks to Prof. Iulian Gherasoiu for guidance and access to the SUNY Polytechnic Institute Nanotechnology Laboratory.
BEDROCK
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