Study of the Long-Term High-Temperature Structural Stability of RuAl Electrodes for Microelectronic Devices

Area of Science:

• Materials Science
• Solid State Chemistry
• Microelectronics Engineering

Background:

• Ruthenium-Aluminum (RuAl)-based materials are promising for high-temperature microelectronic applications.
• Ensuring long-term stability under thermal stress is crucial for device reliability.
• Oxidation protection layers are essential for preventing degradation in ambient or oxidizing environments.

Purpose of the Study:

• To evaluate the long-term high-temperature stability of RuAl-based electrodes.
• To investigate the effectiveness of SiO2 and Al-N-O layers in preventing oxidation.
• To determine the operational temperature limits for RuAl electrodes on Ca3TaGa3Si2O14 (CTGS) substrates.

Main Methods:

• Fabrication of RuAl-based electrodes on CTGS substrates with SiO2 and Al-N-O protective layers.
• Annealing samples in air at 600°C, 700°C, and 800°C for 192 hours.
• Analysis of material degradation using visual inspection and potentially microscopy (implied).

Main Results:

• Minor degradation observed after 192 hours at 700°C.
• Significant oxidation of Aluminum (Al) occurred at 800°C, affecting interconnect electrodes more than contact pads due to dimensional differences.
• The protective layers provided substantial, though not complete, oxidation resistance.

Conclusions:

• RuAl-based electrodes demonstrate reliable long-term stability in air up to 700°C.
• Oxidation is the primary degradation mechanism at elevated temperatures, influenced by electrode geometry.
• Application in less oxidizing atmospheres could extend operational temperature and duration significantly.