Addition of oxygen was used to control the in-plasma photo-assisted etching (PAE) of p-type Si(100) and poly-Si in a high density, inductively coupled, Faraday-shielded, Ar/Cl₂ (225/25 SCCM), 60 mTorr plasma. After etching, samples were transferred under vacuum to an UHV x-ray photoelectron spectroscopy chamber for surface analysis. Samples etched under PAE conditions (ion energies below the ion-assisted etching, IAE, threshold) had a thicker surface oxide and lower [Cl] surface concentration, when compared to samples etched under IAE conditions (ion energies above the IAE threshold). PAE was found not to be affected by 0.1 or 0.25 SCCM O₂ addition, while etching stopped with more than 0.5 SCCM O₂ addition. IAE with RF power on the sample stage, resulting in −65 V self-bias, was not affected by up to 2 SCCM of oxygen addition but decreased rapidly when more than 5 SCCM O₂ was added to the plasma. These results imply that PAE may be completely suppressed, while IAE occurs unobstructed. The implications of these findings are discussed in view of applications involving continuous wave and pulsed-plasma processes.

中文翻译：

---

O2添加量对氯气中Si的光辅助刻蚀的影响

添加氧气用于控制高密度，感应耦合，法拉第屏蔽的Ar / Cl ₂（225/25 ）的p型Si（100）和多晶硅的等离子体内光辅助蚀刻（PAE）SCCM），60 mTorr血浆。蚀刻后，将样品在真空下转移到UHV X射线光电子能谱室进行表面分析。与在IAE条件下（离子能量高于IAE阈值）蚀刻的样品相比，在PAE条件下（离子能量低于离子辅助蚀刻，IAE，阈值）蚀刻的样品具有较厚的表面氧化物和较低的[Cl]表面浓度。发现添加0.1或0.25 SCCM O ₂不会影响PAE ，而刻蚀会超过0.5 SCCM O ₂停止加成。样品台上具有RF功率的IAE导致-65 V自偏置，不受最多2 SCCM氧气添加的影响，但是当向血浆中添加5 SCCM O ₂以上时，其迅速下降。这些结果表明，PAE可能被完全抑制，而IAE的发生不受阻碍。鉴于涉及连续波和脉冲等离子体过程的应用，讨论了这些发现的含义。