As microelectronics become an increasingly integral part of modern society, the greenhouse gas emissions associated with their use and production are increasing at the same time. Semiconductor manufacturing accounts for 31% of global greenhouse gas emissions, and a U.S. Department of Energy analysis of Intergovernmental Panel on Climate Change data shows that by 2030, semiconductor-related greenhouse gas emissions will be It is estimated that this could increase by four times.
But research efforts are underway to reduce the environmental impact of this important field, thanks to a team of students at Arizona State University’s Ira A. Fulton College of Engineering who are exploring ways to make microelectronics manufacturing more environmentally friendly. is in progress. Their research is sponsored by TSMC, one of the world’s largest microelectronics manufacturers, which is increasing its presence as part of the rapid expansion of the semiconductor industry in Arizona.
The potential of diamond electronics shines brightly
Undergraduate students in the Fulton Undergraduate Research Initiative, known as FURI, work under faculty to apply knowledge gained in the classroom through hands-on research experiences. TSMC funded eight FURI projects related to semiconductor manufacturing in the fall 2024 semester, some of which focused on increasing the sustainable use and manufacturing of semiconductors.
The project, sponsored by Fulton School electrical engineering student David McComas, focuses on reducing the energy consumption of power and radio frequency (RF) electronics. Power electronics converts and conditions electricity so that the right amount and type is used in electrical equipment, and RF electronics is used in communications technology.
McComas is investigating the use of diamond static induction transistors. Transistors in RF devices amplify electronic signals for transmission in communications and radar systems, and transistors in power electronics control the flow of current.
Diamond has improved electronic properties over other commonly used materials, making it a promising semiconductor material. These properties include the highest known thermal conductivity of the material, resulting in high levels of heat dissipation and reduced cooling requirements. High breakdown areas require less material to handle high voltages. The wide bandgap also allows this material to output more power while withstanding the high temperatures caused by the heat generated by its use.
The application of diamond as a semiconductor material also reduces power losses across devices using it, which in turn reduces the power required to power diamond devices.
“We can create a new generation of devices that are smaller, faster, more efficient, and more sustainable than the devices we currently use,” McComas says.
According to the U.S. Environmental Protection Agency, 25% of U.S. greenhouse gas emissions in 2022 will come from electricity generation, so this reduction in electricity use could improve environmental impact.
McComas’ fall 2024 FURI project will involve simulating the operation of diamond microelectronics using technical computer-aided design (TCAD) software on the ASU Research Computing Sol supercomputer, part of ASU’s research core facility. Includes things to do. Then, analyze the performance of the simulated device and plan the process to manufacture the prototype in ASU NanoFab. ASU NanoFab is a semiconductor manufacturing facility located on the Tempe campus and is part of the Core Facilities.
By testing various device designs under the supervision of Fulton School assistant professor of electrical engineering Nidin Kurian Kalarikal and Kalarikal’s doctoral students, McComas was able to determine the performance gains from using diamond materials. The aim is to maximize the above advantages.
As a student in ASU’s Barrett Honors College, McComas made this project part of his required senior thesis. His Fall 2024 FURI research builds on the Spring 2024 FURI project, and he will continue researching the feasibility of diamond static induction transistors and their applications in NanoFabs in Spring 2025.
After graduating in spring 2025, McComas aims to continue researching diamond electronic devices.
“There are three long-term hopes for this project,” he says. “First, we will use diamond devices to build a stronger, more robust wireless infrastructure in the United States and around the world. Second, this research will contribute to the field of diamond manufacturing and foster further innovation.” Finally, systems and circuit engineers use devices to solve unique and unexpected problems.
Reducing emissions sources in electronics manufacturing
Jay Schroeder, an undergraduate student in the Fulton School’s chemical engineering department, focused the FURI project he sponsored on another aspect of sustainability related to semiconductors: reducing greenhouse gas emissions during manufacturing. I decided to give it a shot.
Under the supervision of Shuguang Deng, a professor of chemical engineering at the Fulton School, Schroeder is researching the effectiveness of porous, crystalline materials known as zeolites to adsorb a gas called tetrafluoromethane, which is used during the etching process in semiconductor manufacturing. I’m researching sex. Etching is the removal of a portion of semiconductor material to allow placement of other components later in the manufacturing process.
Tetrafluoromethane is a greenhouse gas that causes about 6,500 times more atmospheric warming than carbon dioxide. Current semiconductor manufacturing methods use cryogenic distillation to capture the gases, compressing and freezing them so they don’t escape into the air.
This process does not capture all of the released tetrafluoromethane and requires a large amount of energy to capture it. In contrast, zeolite materials can bind gas molecules together with little to no electricity, and even if they leak, only a small amount of tetrafluoromethane is left uncaptured.
“With or without electricity, the gas only needs to pass through the surface, and the surface combines with the tetrafluoromethane, removing it from the air, much like exhaust gas passes through a car’s catalytic converter. “The zeolite surface holds the car,” Schroeder says.
He investigates the predicted effectiveness of various zeolite materials using density functional theory, which calculates expected and yet unidentified properties of the materials. Schroeder used this theory to narrow down which zeolite materials are suitable for capturing tetrafluoromethane, and then simulated the expected performance through a grand canonical Monte Carlo method to more accurately understand the behavior of the zeolites. predict.
After Schroeder runs the simulations and completes his portion of the project, Deng will use the results to determine which zeolite materials to physically test with graduate students in a laboratory environment under various conditions. .
Building a greener electronics future
Deng said the sponsorship from TSMC has increased his research opportunities.
“TSMC’s commitment to supporting sustainability-oriented research at the undergraduate level is truly commendable,” he says. “This funding will not only advance sustainability in semiconductors, but also support the broader science, technology, engineering and mathematics ecosystem by investing in young researchers ready to drive future innovation. I will strengthen it.”
As a mentor for the FURI project, Deng encourages undergraduate students to participate in semiconductor research throughout the program.
“Projects like this provide technical experience and help students understand the importance of sustainable practices in technology-driven industries,” he says. “Working on industry-supported research will also give you valuable insight into potential career paths and strengthen your problem-solving skills, which are highly sought after in the semiconductor field.”
