STATE-OF-THE-ART SYNTHESIS AND POSTDEPOSITION PROCESSING OF LARGE-AREA CVD DIAMOND SUBSTRATES FOR THERMAL MANAGEMENT

Primarily due to its outstanding thermal conductivity and high electri cal resistivity, diamond is an ideal heat spreader for a variety of ap plications such as multichip modules (MCMs), laser diode arrays, power modules, etc. For these and similar applications, there is a requirem ent for the synthesis and post-deposition processing of high quality, stress-free, large area a (1-100 cm(2)), CVD diamond substrates. Altho ugh the thermal characteristics of CVD diamond are primarily determine d by proper nucleation and growth conditions, post-deposition processi ng such as polishing, planarization, drilling/cutting, and metallizati on are required for the practical application of diamond as a heat spr eader. Such processes should be fast, compatible with conventional ele ctronic packaging, adaptable to large area fabrication, environmentall y-safe, and economically-viable. In the past few years, significant te chnological advances have been made in all these areas. Furthermore, t he cost of these processes has been decreasing steadily so that fabric ation of diamond-based electronic products is becoming affordable. Thi s paper reviews the present technological and economic status of CVD d iamond for thermal management applications.