The scanning tunneling microscope

Working at the IBM Zurich Research Laboratory in the late 1970s, Binnig and Rohrer both had backgrounds in superconductivity. They were mutually fascinated by the study of atomic surfaces — and frustrated by the lack of exploratory tools. The conventional microscope is highly useful for observing very small objects, but its optical lenses are powerless on objects smaller than a wavelength of light. The electron microscope can capture images of extremely small objects by directing electron beams toward an object — but not at the level of individual atoms. So Binnig and Rohrer conceived of an instrument that would allow them to see and manipulate atoms at the nanoscale level.

They built on the work of Russell D. Young, a researcher at the National Bureau of Standards, who in the 1960s and early 1970s combined a tunneling current with a scanning device to obtain information about the nature of metal surfaces. During their 27 months of development, they fine-tuned the design to accurately produce measurements on a minuscule scale. These included reductions in vibrations and noise as well as more precise control of the scanning tip’s location, movement, sharpness and shape. In January 1979, Binnig and Rohrer submitted their first patent disclosure on the STM. Soon after, with the help of fellow researcher Christoph Gerber, they began design and construction.

Announced in 1981, the STM had an immediate impact on broad swaths of science and industry, but nowhere more so than in semiconductors, where granular knowledge of materials and atomic-level behavior have enabled massive advances in chip miniaturization. In September 1985, IBM introduced a handheld version of the STM, and subsequent refinements improved the precision of the mechanical design and resulted in increasingly clearer images.