Effects of Titanium Layer Oxygen Scavenging on the High-k/InGaAs Interface

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanoelectronics

Background:

• Passivating high-k/InGaAs interfaces is crucial for advanced nanoelectronics.
• High defect densities at these interfaces hinder device performance.

Purpose of the Study:

• To investigate the oxygen scavenging effect of thin titanium (Ti) layers on high-k/InGaAs gate stacks.
• To understand how Ti influences the passivation of InGaAs native oxides.

Main Methods:

• Utilized synchrotron X-ray photoelectron spectroscopy (XPS) with in situ metal deposition.
• Performed electrical characterization using capacitance-voltage (C-V) and conductance-voltage (G-V) measurements.
• Analyzed Pt/Ti/Al2O3/InGaAs and Pt/Al2O3/InGaAs capacitor structures before and after annealing.

Main Results:

• Observed remote oxygen removal from the InGaAs native oxide through Al2O3 and HfO2 layers via Ti's scavenging effect.
• XPS confirmed a decrease in InOx features after Ti deposition and further reduction post-annealing.
• Ti 2p spectra indicated oxidation of the Ti layer during XPS measurements.

Conclusions:

• Thin Ti layers act as effective remote oxygen scavengers in high-k/InGaAs gate stacks.
• This remote oxygen scavenging influences the density of interface traps at the high-k/InGaAs interface.
• The findings offer a pathway to improved passivation for InGaAs-based nanoelectronic devices.