MOSCAP-Al2O3-2026-009

Al₂O₃ MOS capacitor — C-V profiling and Mott-Schottky

Identity

Sample ID	MOSCAP-Al2O3-2026-009
Title	Al₂O₃ MOS capacitor — C-V profiling and Mott-Schottky
Status	Completed
Operator	Dr. N. Şahin
Laboratory / Facility	Dielectric Characterization Lab

Substrate / Material

Substrate Material	p-type Si (100)
Doping Type	p (Boron)
Doping Concentration	≈1×10¹⁵ cm⁻³
Active Layer Material	Al₂O₃ high-k dielectric (ALD)

Notes

Tags	LCR, C-V, Mott-Schottky, dielectric, MOS, Dit
Notes	MOS-cap: Al/Al₂O₃/p-Si. Multi-frequency C-V + Dit by the conductance method.

Process Steps

Al₂O₃ dielectric — ALD (Thin Film Fabrication)

Technique	ALD
Material / Target / Precursor	Al₂O₃ (TMA + H₂O)
Purity	99.999% TMA
Equipment	Beneq TFS200
Substrate Temperature (°C)	200
Duration (min)	30
Rate (nm/min or Å/s)	~1.1 Å/cycle, 180 cycles
Target Thickness (nm)	20
Measured Thickness (nm)	19.8
Post-processing	Top gate Al (100 nm) shadow mask; back contact Al

Multi-frequency C-V (Measurement Context)

Instrument	Keysight E4980A LCR meter
Calibration Status	Open/short compensation performed
Uncertainty (±)	±0.1% C
Caption	1/10/100 kHz and 1 MHz; Vg −3→+3 V. Accumulation/depletion/inversion regions.

C_ox ≈ 380 nF/cm² → k(Al₂O₃) ≈ 8.6. Low frequency dispersion (good interface).

Dit by conductance method + Mott-Schottky (Measurement Context)

Instrument	Keysight E4980A + DC bias
Calibration Status	Valid
Uncertainty (±)	±5% Dit
Caption	G-V/ω method; 1/C² (Mott-Schottky) in the depletion region for doping density.

N_A ≈ 1.1×10¹⁵ cm⁻³ from the Mott-Schottky slope (consistent with nominal).

Dielectric/interface metrics (Result (Spec))

Parameter	Value	Uncertainty (±)	Unit	Specification	Pass
Relative dielectric constant k	8.6	0.3	—	8–9	✓
EOT (equivalent oxide thickness)	9.0	0.4	nm	—	✓
Interface trap density Dit	2.3e11		eV⁻¹cm⁻²	≤5e11	✓
Fixed oxide charge Qf	1.4e11		cm⁻²	≤5e11	✓
Leakage @1 MV/cm	3e-8		A/cm²	≤1e-6	✓