A ultra-high-vacuum wafer-fusion-bonding system

Area of Science:

• Semiconductor device fabrication
• Materials science
• Surface chemistry

Background:

• Heterojunction device design is often limited by material integration and energy band alignment.
• Wafer bonding overcomes limitations of epitaxial growth for materials with significant lattice mismatch.
• Interface dipoles, controlled by surface chemistry, are crucial for tuning energy band alignment.

Purpose of the Study:

• To develop an ultra-high-vacuum (UHV) system for wafer-fusion-bonding semiconductors.
• To enable in situ control and measurement of surface properties influencing interface dipoles.
• To present the system design and initial results for InGaAs/Si heterojunctions.

Main Methods:

• Integration of a wafer-fusion-bonding chamber with annealing capabilities into a UHV system.
• Incorporation of sputtering and X-ray photoelectron spectroscopy (XPS) for surface preparation and analysis.
• In situ monitoring of surface chemistry prior to wafer bonding.

Main Results:

• A novel UHV system for semiconductor wafer bonding was successfully designed and implemented.
• The system allows for precise control over surface chemistry, critical for managing interface dipoles.
• Initial results demonstrate the feasibility of fusion-bonded InGaAs/Si heterojunctions using the developed system.

Conclusions:

• The developed UHV system provides a pathway for fabricating advanced heterojunction devices with tailored band alignments.
• Precise control over surface chemistry is demonstrated as a key factor in achieving desired interface properties.
• This approach facilitates the integration of dissimilar semiconductors, expanding possibilities in electronic device design.