Award for Study of Ultrathin Silicon Dielectrics

Hisham Massoud

Professor Hisham Massoud of Duke’s Pratt School of Engineering has been awarded the 2006 Electronics and Photonics Division Award of the Electrochemical Society (ECS) for his work on ultrathin silicon dielectric films. Such ultrathin films are a basic component in silicon microelectronics, and increasingly thinner films improve the performance of future generations of microchips.

Massoud received the award at the 209th annual ECS meeting held on May 7-12 in Denver where he was also elected an ECS fellow for his contributions.

“As the size of the transistors shrinks for faster and smaller microchips, the scaling the thickness of high-quality silicon dioxide films becomes more important,” said Massoud, professor in the Pratt School’s Department of Electrical and Computer Engineering since 1983. “The driving force is the desire to produce smaller integrated circuits operating at higher speeds.” Massoud was recently named chair of the Electrical and Computer Engineering Department.

In microchips or integrated circuits, hundreds of millions of tiny transistors are fabricated. Transistors carry out countless analog and digital functions in computation, communications, sensing and control systems. They are found in all electronic systems from a simple alarm clock to the space shuttle control systems.

“Transistors are without a doubt the most abundant man-made object in history,” Massoud said. “Nothing has been made in larger numbers.”

Massoud started his study of ultrathin layers of silicon dioxide in the 1980s as a graduate student at Stanford University. His work led to the development of a process model of the growth of ultra-thin layers of silicon dioxide based on their chemical and physical properties. This process model is found in software tools used by device technologists to grow such layers in a manufacturing line.

At Duke, he developed a basic understanding of the fundamental relationship between the chemical properties of semiconductor interfaces and their electronic properties. This model explains the dependence of the electronic properties of transistors on their manufacturing and processing history.

In recent years, his attention has focused on problems arising from the continuous reduction in the scale of semiconductor devices.

“If you keep thinning oxide layers, there is a certain thickness below which the quantum mechanical phenomenon of tunneling starts to change everything,” Massoud said. “It changes the way transistors operate, the way that we model and simulate them, the way that we measure their properties, and the performance of integrated circuits.”

Gate tunneling results when charge carriers in semiconductors, such as electrons and holes, move through an ultrathin dielectric layer much like a wave of light goes through glass, Massoud explained. This work is leading to the description of the ultimate smallest transistor, he said.

In addition to his role at Duke, Massoud served as a research scientist at the IBM Thomas J. Watson Research Center, Yorktown Heights, N.Y., in 1977 and 1980-81, the Microelectronics Center of North Carolina in 1987, the Hewlett-Packard Integrated Circuits Business Division in 1992, and the Max-Planck Institute for Microstructure Physics in 1997 and 1998. He is a fellow of the Institute of Electrical and Electronics Engineers.

The Electrochemical Society was founded in 1902 as a forum for developments in the burgeoning field of electrochemistry. The electronics division award was established in 1968 to encourage excellence in electronics research and outstanding technical contributions to the field of electronics science and technology.