Thermal and optical applications of thin film diamond

Abstract

Virtually all recent reviews of the market potential for chemical vapour deposited (CVD) diamond have featured the thermal management of electronic semiconductor devices as an imminent application for this new material. There is an existing market for natural diamond substrates (‘heat sinks’) in sub-millimetre sizes, and their thermal performance has been extensively studied, CVD diamond heat sinks in millimetre and larger sizes are already in use, but there are constraints to their applicability arising from thermal and mechanical factors. Their advantages and limitations are discussed. The first ‘optical’ applications of CVD diamond films were as X-ray transmissive components (lithography masks and windows for soft X-ray detectors), but with improvements in the technology of CVD diamond growth a larger market for wide-band infrared transmissive windows is now developing. This results from the availability of large area (greater than 1000 mm 2 ) CVD diamond plates of adequate thickness and with transparency achieved through control of diamond grain size and orientation.