Active and Passive Electronic Applications of CVD Diamond Films

Abstract

The synthesis of thin diamond films utilizing plasma-enhanced CVD techniques is receiving world-wide attention. Diamond exhibits several remarkable properties that make it a highly desirable material for passive and active electronic device applications. The critical properties of interest in this context include the wide band gap (5.45 eV), exceptional thermal conductivity (20 W/cm o K), high electrical resistivity (1016 Ohm cm) and the high elastic modulus (10.35 * 1012 Dynes/cm2) of diamond. In this paper we will discuss some of the potential near-term applications of thin, polycrystalline diamond films. In the context of passive electronic applications diamond films can be used for the fabrication of heat sinks, capacitors in conjunction with silicon, passivation layers on gallium arsenide devices and x-ray lithography mask membranes. The utility of polycrystalline diamond films of controlled grain structure in certain active electronic device applications will also be discussed. Devices in this category include MESFETS and photoconductive switches. In all these cases the ability to control the structure and the impurity content of the diamond films is critical to the eventual successful application of these films. Some of the aspects of structure and impurity control to be discussed will include issues of nucleation and growth of the films, the control over the grain size and structure and the doping of diamond films.