Self-limiting surface reactions are promising for atomic layer etching of materials. Classical treatments with plasmas do not allow for self-limiting functionalization but cause the formation of several functional groups and degradation. To avoid this, the polystyrene was oxidized in the plasma afterglow with the O-atom density 7 × 10¹⁷ m⁻³ and dissociation fraction 7%. X-ray Photoelectron Spectroscopy was used to study the formation of various oxygen groups versus the O-atom dose. The surface was saturated with the OH groups already after the dose of 1 × 10¹⁹ m⁻², indicating a large initial sticking. The functionalization remained almost intact over an order of magnitude larger doses. Measurable quantities of the CO groups appeared simultaneously with the benzene ring's degradation at a dose of 1 × 10²⁰ m⁻². The ring degradation was accomplished with a significant increase in the OH concentration what was explained by the formation of a thicker oxygen-rich film. OCO and O(CO)O groups appeared after the dose of 1 × 10²¹ m⁻², i.e., a 100-times larger dose than required for the initial saturation with the OH. The observations are sound with the predictions from the literature obtained through the density functional theory of oxygen adsorption on polystyrene.

自限表面反应有望用于材料的原子层蚀刻。用等离子体进行的经典处理不允许自我限制的功能化，但会导致几个功能基团的形成和降解。为了避免这种情况，聚苯乙烯在等离子体余辉中被氧化，O原子密度为7×10 ¹⁷ m ^-3，离解分数为7％。X射线光电子能谱法用于研究各种氧基团与O原子剂量之间的关系。在1×10 ¹⁹ m ^-2的剂量后，表面已经被OH基团饱和，这表明初始粘附力很大。在更大剂量的数量级上，功能化几乎保持完整。可测量的C量O基团与苯环的降解同时出现，剂量为1×10 ²⁰ m ^-2。环的降解通过OH浓度的显着提高而完成，这可以通过形成较厚的富氧膜来解释。在1×10 ²¹ m ^-2的剂量（即比用OH初始饱和所需的剂量大100倍的剂量）后出现O C O和O （C O）O基团。根据通过氧在聚苯乙烯上的吸附的密度泛函理论获得的文献预测，这些观察结果是合理的。