Diamond Films: Recent Developments

Abstract

Carbon in the form of diamond is the stuff of dreams, and the image of the diamond evokes deep and powerful emotions in humans. Following the successful synthesis of diamond by high-pressure methods in the 1950s, the startling development of the low-pressure synthesis of diamond films in the 1970s and 1980s almost immediately engendered great expectations of utility. The many remarkable properties of diamond due in part to its being the most atomically dense material in the universe (hardness, thermal conductivity, friction coefficient, transparency, etc.) could at last be put to use in a multitude of practical applications. “The holy grail”—it was realized early on—would be the development of large-area, doped, single-crystal diamond wafers for the fabrication of high-temperature, extremely fast integrated circuits leading to a revolution in computer technology.Excitement in the community of chemical-vapor-deposition (CVD) diamond researchers, funding agencies, and industrial companies ran high in expectation of early realization for many of the commercial goals that had been envisioned: tool, optical, and corrosion-resistant coatings; flat-panel displays; thermomanagement for electronic components, etc. Market projection predicting diamond-film sales in the billions of dollars by the year 2000 was commonplace. Hopes were dashed when these optimistic predictions ran up against the enormous scientific and technical problems that had to be overcome in order for those involved to fully exploit the potential of diamond. This experience is not new to the scientific community. One need only remind oneself of the hopes for cheap nuclear power or for high-temperature superconducting wires available at hardware stores to realize that the lag between scientific discoveries and their large-scale applications can be very long. Diamond films are in fact being used today in commercial applications.