Capacitance-Voltage of Al2O3 Gate Dielectric by ALD

on Enhancement-mode InGaAs MOSFET

Y. Xuan, H. C. Lin, P. D. Ye, and G. D. Wilk, “Capacitance-voltage studies on enhancement-mode InGaAs metal-oxidesemiconductor field-effect transistor using atomic-layer-deposited Al2O3 gate dielectric”, Appl. Phys. Lett., 88, 263518 (2006).

Outline

• Cross sections of an InGaAs MOSFET and an capacitor• Leakage current in different thermal annealing• C-V curve at high frequence• I-V Characteristic Curve on InGaAs MOSFET• Hysteresis in the CV loops measured at half value of acc-

capacitance vs the small signal frequency • The accumulation capacitances and the normalized ones vs the

small signal frequency at a wide range on the similar device• Split-CV Curve on MOSFET• The flat-band voltages vs the small signal with different oxide

thicknesses

Cross Sections of an E-mode Al2O3 /InGaAs MOSFET and

an Capacitor

At 750-850⁰ by RTA in N2

Al2O3 : Amorphous film

Leakage Current in Different Thermal Annealing

850 C is critical temperture⁰

C-V Curve at High Frequence

Hysteresis in the C-V Loop

unannealing─hysteresis of ~200-500mV

10-50 mV

The bulk and interface properties start to degrade after annealing temperture higher than 800 C⁰ .

The acc-Capacitancesvs.

Frequency at Wide Range

Frequency dispersion is only 1% at this frequencyrange

The Flat-band Voltages vs

The Small Signal Frequency

Split-CV Curve on MOSFET

I-V Characteristic Curveof Enhancement-mode In-GaAs MOSFET