Expert advances Semiconductor Innovation with Breakthrough in Low-Temperature Etch-Stop Layer Deposition for FinFETs

By Tosin Clegg

As the global semiconductor industry races toward smaller, more powerful, and energy-efficient chips, Oluwadamilola Ifeoluwa Egbeyemi, a Nigerian-born chemical engineering researcher who graduated from the University of Toledo, is making waves with a breakthrough in FinFET fabrication. His recent study, published in the World Journal of Advanced Research and Reviews, proposes a novel approach to one of the most pressing challenges in advanced logic device manufacturing: the reliable deposition of conformal etch-stop layers at low temperatures.

The research, titled “Designing Low-Temperature Plasma-Enhanced Chemistries for Conformal Etch-Stop Layer Deposition in Advanced FinFET Structures,” explores how cutting-edge plasma-enhanced atomic layer deposition (PEALD) techniques can enable next-generation chip design without the thermal penalties traditionally associated with thin film deposition.

“Traditional thermal deposition methods often struggle with step coverage in high-aspect-ratio features. This leads to inefficiencies and yield loss in FinFET (Fin Field Effect Transistor) production,” Egbeyemi explained. “My work offers low-temperature plasma chemistries that are not only conformal but also prevent plasma-induced damage in complex 3D transistor structures.”

FinFETs have replaced conventional planar transistors in high-performance computing due to their superior electrostatic control and scalability. However, as manufacturers move toward the 3 nm node and beyond, ensuring precise material layering without damaging sensitive structures has become a major hurdle. This is especially critical in densely packed gate-all-around (GAA) architectures and narrow fins, where a single defect can compromise performance or cause complete failure.

Egbeyemi’s approach utilizes organometallic precursors in tandem with tailored plasma reactants at temperatures below 150°C. This is particularly beneficial for integrating etch-stop layers like silicon nitride (SiNx), hafnium oxide (HfO₂), and boron carbide (BxCγ), which are essential in maintaining structural fidelity during aggressive plasma etching steps.

“My goal was to achieve over 90% step coverage in trenches with aspect ratios above 20:1,” he noted. “Through the use of remote and pulsed plasma modes, I optimized precursor adsorption and minimized ion bombardment. The result was a highly uniform, dense, and stable film, suitable for real-world FinFET integration.”

To validate the effectiveness of his deposition techniques, Egbeyemi employed advanced diagnostic tools such as quartz crystal microbalance (QCM), Fourier-transform infrared spectroscopy (FTIR), and ellipsometry. These tools allowed for in situ analysis of film growth per cycle, conformality, and hydrogen incorporation — all of which influence long-term device reliability.

The implications of this work are significant for semiconductor foundries looking to improve pattern fidelity, etch selectivity, and line-edge roughness across device generations. In test structures mimicking commercial FinFET stacks, Egbeyemi’s plasma-enhanced films improved gate leakage characteristics and contributed to better line-edge definition.

Egbeyemi emphasized the importance of process flexibility in today’s semiconductor ecosystem. “It’s not just about developing a material; it’s about building a scalable process that can be tuned for a wide range of etch-stop applications, including self-aligned double patterning and extreme ultraviolet (EUV) lithography,” he said.

Beyond the technical depth of the research, Egbeyemi’s work reflects a broader vision for inclusive global contributions to frontier technologies. With academic roots in Nigeria and advanced research training in the United States, his journey exemplifies the growing impact of African scientists in shaping the future of microelectronics and nanofabrication.

His paper also addresses the growing demand for eco-friendly, low-energy fabrication solutions. By lowering the substrate temperature for film deposition, his methodology reduces thermal stress on wafers and minimizes energy consumption—an important consideration as the industry pushes for greener manufacturing.

Currently pursuing more research projects in advanced pattern transfer techniques for semiconductor manufacturing, Egbeyemi is focused on bridging the gap between laboratory innovation and industrial application. His work has attracted interest from collaborators in both academia and the semiconductor industry.

“I believe the future of chip design will be determined not just by transistor architecture, but by how we innovate the surrounding process technologies,” he remarked. “Etch-stop layers may seem like a small part of the puzzle, but they’re fundamental to the performance and reliability of every modern logic device.”