Researchers from the Université de Sherbrooke and their international collaborators have made significant strides in semiconductor technology, with their latest breakthrough in 3D interconnects for III-V semiconductor heterostructures. This innovative development promises to transform the landscape of miniaturized power devices, paving the way for more efficient and compact solutions in various high-tech fields.
Revolutionizing power devices with 3D interconnects
The team, including scientists from the Laboratoire Nanotechnologie Nanosystèmes (LN2) and partners from Grenoble, France, and Ottawa, Canada, have successfully fabricated 3D interconnects on a multijunction solar cell. This new approach leverages advanced processes like III-V heterostructure plasma etching, gold electrodeposition, and chemical mechanical polishing to integrate through-substrate vias with unprecedented precision.
Enhancing efficiency and reducing size
Traditional two-dimensional (2D) frameworks for power device densification face increasing challenges due to lithography and packaging limitations. The shift to a three-dimensional (3D) integration model not only circumvents these issues but also enhances the power density and miniaturization capabilities of devices. By integrating through-substrate vias (TSVs) into the design, the researchers have achieved a substantial increase in wafer area utilization and power yield per wafer. This approach is particularly beneficial for high-frequency devices and applications requiring high current densities, such as thermophotovoltaic cells and micro solar cells.
Applications and future potential
The implications of this technology are far-reaching. In photovoltaics, the use of TSVs significantly reduces shading factors and series resistance losses, which can enhance the conversion efficiency and overall performance of solar cells. The innovations also open new possibilities for power-over-fiber systems, Internet of Things (IoT) devices, and microconcentrator photovoltaics, where space and efficiency are paramount.
Technical breakthroughs and fabrication process
The researchers employed a comprehensive set of fabrication steps starting with plasma etching of the III-V/Ge triple junction heterostructure, followed by dielectric isolation and via metallization using gold electroplating. A key part of their process involved the innovative use of polydimethylsiloxane (PDMS) bonding to maintain the mechanical integrity of the device during substrate thinning. This meticulous approach has resulted in devices with areas significantly smaller than traditional chips, yet with much higher efficiency.
As the demand for smaller, more efficient power devices continues to grow, the advancements made by the Université de Sherbrooke and its partners are set to play a crucial role in meeting these needs. The successful implementation of 3D interconnects in III-V semiconductor heterostructures represents a major leap forward, promising enhanced performance and new possibilities in a variety of high-tech applications.
To learn more, read the full research article: 3D Interconnects for III-V Semiconductor Heterostructures for Miniaturized Power Devices by Mathieu de Lafontaine et al., October 2023.
