Material-Mechanistic Interplay in SiCN Wafer Bonding for 3D Integration

Area of Science:

• Materials Science
• Semiconductor Manufacturing
• Surface Chemistry

Background:

• Wafer bonding is critical for advanced CMOS device architectures, requiring high bonding strength, low distortion, and alignment accuracy.
• Reducing the thermal history during bonding is a key challenge in semiconductor processing.
• Limited research exists on interface mechanisms during low-temperature annealing in wafer bonding.

Purpose of the Study:

• To investigate the effectiveness of plasma-activated bonding using silicon carbon nitride (SiCN) for low-temperature annealing.
• To evaluate the bonding strength and interfacial water content after annealing.
• To understand the interface mechanisms contributing to bonding strength at low temperatures.

Main Methods:

• Plasma-activated wafer bonding using SiCN as the dielectric material.
• Post-bond annealing at a low temperature of 250 °C.
• Evaluation of bonding strength and residual water at the interface.
• Surface and interface analysis.

Main Results:

• SiCN films achieved significant bonding strength after low-temperature annealing (250 °C).
• The bonding process effectively consumed all interfacial water.
• Surface and interface analyses indicated that carbon bonding is key to achieving a strong interface via low-temperature annealing.

Conclusions:

• Plasma-activated bonding with SiCN is a viable method for achieving high bonding strength at low temperatures.
• This technique addresses the challenge of reducing thermal history in semiconductor device fabrication.
• The carbon bonding within the SiCN interface plays a crucial role in enabling robust low-temperature wafer bonding.