| 摘要 |
<p>A block of dielectric material having a long axis and a short axis and having low losses at a selected microwave frequency and a dielectric constant selected to produce a desired degree of phase modulation is mounted on a rotatable shaft in an orientation perpendicular to the long and short axes and arranged inside a waveguide feeding a CVD reactor containing a plasma species. The block is spun by a rotational force applied to the shaft at an angular acceleration such that the two axes of the block successively intersect the axis of the waveguide within the decay period of the plasma species. The frequency of phase modulation can be varied by changing the angular acceleration of the shaft, and the amplitude of the phase modulation can be varied by changing the ratio of block length to thickness and/or by selecting a material with higher dielectric constant. The incident microwave power may be modulated as a function of angular position of the spin shaft. By moving the apparent plasma and modulating the applied microwave power, a customized temperature profile may be achieved over a desired substrate area. <IMAGE></p> |
