Diamond films grown by plasma enhanced chemical vapor deposition (CVD) have become commercially important engineering materials. Microwave plasma CVD is a particularly valuable synthesis technique because it produces the highest quality diamond with the best thermal, electronic, and optical properties. However, microwave CVD has been difficult to scale up, greatly limiting its commercial viability and CVD diamond's potential markets. Phase I has already demonstrated a fourfold improvement in the economics of microwave diamond film growth, with equally dramatic gains in the size of the individual articles which can be coated. In the Phase II program proposed, we intend to transfer our lab-scale results to large scale deposition equipment used in commercial production. This will be accomplished by modifying and instrumenting one of Crystallume's 915 MHz commercial production reactors. A mass spectrometer will perform in situ sampling of active species at the diamond growth surface as a function of plasma and gas injection configurations, and other analytic tools including optical emission spectroscopy will be used to characterize the process. This will permit us to identify the reactor configuration and operating conditions which lead to the most cost efficient production of diamond films.
