Rohrer and Binnig Invent the Scanning Tunneling Microscope

Gerd Binnig and Heinrich Rohrer developed the scanning tunneling microscope, which allowed scientists to map three-dimensional, high-resolution surfaces and to control matter at the atomic level.

Significance

The development of the STM had a great impact on scientific research as well as on technological advances, and in 1986, Binnig and Rohrer shared one-half of the Nobel Prize in Physics Nobel Prize in Physics;Gerd Binnig[Binnig] Nobel Prize in Physics;Heinrich Rohrer[Rohrer] for their work on the design of the STM (Ruska received the other half of the Nobel Prize in Physics Nobel Prize in Physics;Ernst Ruska[Ruska] in that same year for his work in electron optics). The STM has several advantages over previous microscope techniques. For example, the voltages used for the tunneling are low and nondestructive; the spectrometer does not require an evacuated medium for its operation, as long as an insulator is separating the probe from the sample. The preciseness of the manipulation of the probe allows scientists to map three-dimensional surfaces at the atomic level. Another advantage of the microscope is its capability of distinguishing between the different atomic species on the surface of the specimen. Observations were made on metals, semiconductors, superconductors, and biological matter. Abbe, Ernst Scanning tunneling microscope

The STM found many industrial applications involving both the design and quality-control stages. In the manufacturing of diffraction grating masters, for example, the STM was used to guide the ruling machine cutting the grooves and to examine the quality of the final product. The combination of its lateral and vertical high resolutions makes the STM the only device capable of visualizing the grooves in those devices. The STM was also used in the design of recording heads as well as in the manufacturing of the stampers used to dig holes through compact discs. Further applications are envisioned in the electronic component manufacturing industry.

Most important, the STM was successfully used in the manipulation of matter at the atomic level. In October, 1989, by letting the probe sink into the surface of a metal-oxide crystal, researchers at Rutgers University were able to dig a square hole of about 250 atoms across and 10 atoms deep. A more impressive feat appeared in a report in the April 5, 1990, issue of Nature: M. Eigler and Erhard K. Schweiser of IBM’s Almaden Research Center spelled out “IBM” using thirty-five atoms of xenon. This ability to move and place individual atoms precisely raises several possibilities, which include custom-made molecules, atomic-scale data storage, and ultrasmall electrical logic circuits.

The success of the STM led to several new microscopes developed for the study of other features of sample surfaces. While they share the same scanning probe technique in their measurements, these techniques use different processes for the actual detection. The most popular among these new devices is the atomic force microscope (AFM). This device measures the tiny electric forces that exist between the electrons of the probe and the electrons of the sample without the need for electron flow, which makes the technique particularly useful in imaging nonconducting surfaces. Other scanned probe microscopes use physical properties such as temperature and magnetism to probe the surfaces. Scanning tunneling microscope Microscopes

Rohrer and Binnig Invent the Scanning Tunneling Microscope Summary