栅网与偏压对CHF_3电子回旋共振放电等离子体特性的影响

Effect of grid and bias on the characteristic of CHF_3 electron cyclotron resonance discharge plasma

研究了电子回旋共振等离子体增强化学气相沉积系统中栅网的增加和栅网上施加 +6 0V和 - 6 0V偏压对CHF3放电等离子体特性的影响 .发现在低微波功率下栅网与偏压对等离子体中基团分布的影响较大 ,而高微波功率下的影响逐渐减小 .这是由于低微波功率下等离子体中电子温度较低 ,基团的分布同时受栅网鞘电场和电子碰撞分解的共同作用 ;而高微波功率下电子温度较高 ,栅网鞘电场的作用减弱 。

The characteristics of CHF3 electron cyclotron resonance(ECR) plasma, which is formed in the case of a floating grid in an ECR-chemical vapor deposition system and + 60V or - 60V biased at grid, were investigated by an actinometric optical emission spectroscopy. It is found that the effects of grid and biasing on the distribution of radicals occur mainly at a low microwave input power. It is considered that the distribution of radicals at a low power is controlled by electron collision and sheath potential together due to low electron temperature. However, the effect of sheath potential at a high power decreases due to increasing electron temperature. As a result, the distribution of radicals at a high power is dominated by electron collision.