NANOTIP

One of the current pain point of microelectronic, especially concerning 3D chip, is the detection of electrical and/or physical failures. These failures will create hot spots due to high electrical current density that can be detected at the nanoscale using local probe. Here we propose a new equipment that will address that problem with a much higher spatial and thermal sensitivity with industrial standard of efficiency. This equipment will help to solve the following challenges:

• Efficient dissipation of heat from hotspot regime to increase the working performance of devices

• Energy consumption, dissipation of heat at the micro and nanoscale in modern microelectronic devices.

• Energy harvesting - Photovoltaic, Thermoelectric generators : requires measurement of thermal conductivity of many different materials.

This technology is based on a highly sensitive resistive thermometer made of niobium nitride (NbN) binary compound. Resistive thermometry takes advantage of the temperature-dependent electrical resistance and its temperature sensitivity relies on the temperature coefficient of resistance (TCR). NbN sensor has shown TCR 5 to 10 times higher than existing metallic sensors. The innovation consists of this technology based on integration of NbN thermometer on non-planar AFM probes by performing electronic lithography. It is only mastered by Institut Neel, CNRS (patent pending).

• Highly sensitive thermometer. 4-wire measurement scheme: better signal to noise ratio.

• Higher spatial and thermal resolution.

• A significant improvement in the temperature sensitivity results in detecting extremely small heat flux at nanoscale.

• Improvement in the thermal measurements of nanoscale structures, materials and devices.

Fabrication process to integrate the NbN thermometer at the apex of the AFM tip has been optimized. We have calibrated NbN based thermal probes and demonstrated the sensitivity 5 times higher than the existing probes. Thermal measurements have been carried out on bulk and thin films. Next step, to adapt the process for batch fabrication of thermal probes.

• In-plane temperature profiling of 3D Chips.
• Hotspot detection / Failure mechanism analysis of nano-electronic, optoelectronics devices.
• Characterisation of phase change materials
• Thermal conductivity at nanoscale of structures and devices.
• Heat transport in heterostructured nano-materials.
• To identify the narrowing of interconnected lines due to fabrication errors or electromigration.
• Diagnosis of on-chip resistive elements.