Developments in CVD-Diamond Synthesis During the Past Decade

The last decade and a half has seen an explosive growth in the synthesis of diamond materials by a variety of chemicalvapor-deposition (CVD) processes driven by both scientific curiosity and technological exploitation for diverse applications in the fields of hard coatings, tools, optics, passive and active electronics, thermal management, corrosion protection, and radiation detection. Beginning in the 1980s, micron-sized diamond particles were reported by a few groups using hot filaments and a seemingly magical (alchemical) recipe of hydrocarbons and hydrogen. Now near the end of the 1990s, the basic science of diamond growth by CVD is well-understood. Diverse plasma- and thermal-based techniques have been developed for deposition of diamond. Polycrystalline films several mm thick and over 12 in. (30 cm) in diameter are a reality. Many companies are commercializing a wide range of products, and the cost of deposition has dropped by over three orders of magnitude. This article reviews these developments and highlights challenges for the future. It is organized along two themes: scientific advances and technological progress.