Passivation of Interface Defects in GaN-Based Metal-Insulator-Semiconductor Devices via In Situ Combined Plasma...

Area of Science:

• Materials Science
• Semiconductor Physics
• Surface Science

Background:

• Gallium Nitride (GaN)-based metal-insulator-semiconductor (MIS) devices are crucial for high-performance power electronics.
• Interface defects at the gate dielectric-semiconductor junction limit the performance and reliability of GaN MIS devices.

Purpose of the Study:

• To investigate the effects of in situ H2, N2, and N2/H2 plasma pretreatments on GaN surfaces.
• To develop and evaluate a combined plasma treatment method for GaN surface passivation.

Main Methods:

• Utilized an ultrahigh vacuum-interconnected system for in situ plasma treatments.
• Employed in situ X-ray photoelectron spectroscopy (XPS) and cathodoluminescence (CL) for surface analysis.
• Conducted ex situ atomic force microscopy (AFM) and capacitance-voltage (C-V) measurements.

Main Results:

• The combined plasma pretreatment effectively reduced carbon and oxygen impurities on GaN surfaces.
• Nitrogen vacancies and deep-level defects were compensated and passivated.
• Interface defect density was reduced by nearly an order of magnitude, significantly improving electrical performance.

Conclusions:

• Integrated plasma pretreatments offer a non-destructive method to enhance GaN surface quality.
• This approach significantly improves the electrical characteristics and reliability of GaN MIS devices.
• The findings support the broader application of advanced GaN-based semiconductor technologies.