Paper PS1-WeA11
The Effect of Wall Conditions on the Self-Limiting Deposition of Metal Oxides by Pulsed Plasma-Enhanced Chemical Vapor Deposition

Wednesday, October 17, 2007, 5:00 pm, Room 606

Pulsed plasma-enhanced chemical vapor deposition (PECVD) has been engineered to deliver self-limiting growth (i.e. 1 Å/pulse) of metal oxides such as Ta₂O₅ and Al₂O₃. Pulsed PECVD may serve as a bridge between conventional ALD and PECVD, retaining monolayer control but with potentially much higher throughput. In this process the reactor walls are alternately exposed to atomic oxygen and metal precursors. The degree of adsorption in the latter step can dramatically influence both deposition rates and film quality. The impact of precursor adsorption on the plasma and gas-phase composition in these systems was measured using optical emission spectroscopy and quadrupole mass spectrometry, respectively. It is shown that the time scale for adsorption is much greater than gas-phase residence times. Adsorbed compounds significantly alter the reactor composition, particularly at the initiation of each pulse. As a consequence careful attention must be paid to reactor design and operation in order to control deposition rates and maintain quality.