Building Modern Electronics at the Molecular Level

In our smartphones, tablets, laptops, and other electronic devices, semiconductor components churn away to transmit, process, and display information. Since the birth of the semiconductor industry, there has been a driving force to make individual electronic components smaller, faster, cheaper, and more energy efficient. Today, as these features enter the molecular scale, atomic-level control has become critical.

A PITA-funded collaboration between Gelest, Inc., and two Lehigh University researchers, Nicholas Strandwitz and Gregory Ferguson, has led to the development of a new class of molecules for building electronic components one layer at a time. A novel class of chemical precursors produced by Morrisville, Pennsylvania-based Gelest possesses significant advantages over existing precursors, and the researchers at Lehigh have developed methods for depositing these molecules as single-molecular layers and as oxide thin films, using both solution-based and vapor-based techniques.

The molecules are stable, easily delivered in the vapor phase, and often release no chemical byproducts, which can be detrimental to manufacturing processes, due to contamination concerns. Ferguson noted, “The absence of byproducts in the adsorption of siloxane monolayers is an attractive feature that this approach shares with the emerging fields of additive manufacturing and 3D printing.”

In the first paper explaining their methods, published in Journal of Materials Chemistry C, the researchers describe the use of the new precursors to deposit silica, which is ubiquitous in the microelectronics industry. Despite the widespread use of silica, few vapor growth chemistries are available, making this new process valuable. In a more recent paper in the journal Langmuir, the researchers describe the modification of surfaces with single molecular layers that can tune the surfaces’ properties, for example, the wettability and stability.

The new Lehigh methods are being considered by semiconductor electronics companies for adoption into their processes to aid in the continual downscaling of component sizes, and could have an impact in telecommunications, computing, and energy-conversion systems.

“Molecular-level control of material growth is increasingly essential in modern microelectronics,” said Strandwitz. “The chemistries and analyses done in this PITA collaboration provide a new route to the nanoscale control sought by many semiconductor companies.” Widespread use of Gelest’s molecules would result in increased revenue for the company and possibly drive the development of a next generation of molecular precursors—as well as new collaborations with Lehigh and other universities.