The Physics of Plasma-Induced Charging Damage

ECS-9729968 Giapis图案化表面经常暴露于等离子体，如通过微小的取样孔进行等离子体表征，或在微电子中的蚀刻、沉积和灰化等应用中，以及选择性表面功能化。 通常，图案由不同的材料（绝缘掩模、导电金属或多晶硅、栅极和场氧化物）组成，这些材料由于等离子体鞘出口处的离子和电子之间的方向性差异而充电。 等离子体诱发的充电可引起具有不期望的后果的离子偏转;例如，当蚀刻高纵横比特征时，掩模充电导致侧壁轮廓不规则。 在这个建议中，我们试图揭示等离子体诱导充电的基本物理通过实验和理论相结合的方法集中在密集的亚微米图案的绝缘体和导体类似的等离子体蚀刻过程中遇到的。 大规模的Monte Carlo模拟将结合联合收割机鞘动力学，微观结构充电，静电，反应，散射，电子隧穿通过TN绝缘体，和表面电流揭示成各种相互矛盾的报告等离子体参数对充电损坏的影响。 特别是，我们试图了解所谓的“电子遮蔽”的损害，这会导致灾难性的电子隧穿电流通过多晶硅绝缘体结构中的栅极氧化层的性质。对图案相关充电效应的重要建模工作将扩展到包括隧穿效应和表面电流，并将用于预测：a）电子温度、射频偏置和射频频率对充电损伤的影响。B）依赖于λ比的充电效应。 微负载和电子之间是否存在相关性 影子？c）掩模厚度效应。 使用较薄的硬（氧化物）掩模将如何影响充电 损害？d）特征和晶片尺度效应。 是否充电的一个特定的功能影响损害 邻沟？e）、 脉冲等离子体效应 为什么脉冲等离子体能减少这两种形式的充电损伤？f）的 新的器件布局规则，以消除充电损伤。模拟结果将通过在螺旋谐振器中产生的高密度等离子体中进行广泛的蚀刻实验来验证

ECS-9729968GiapisPatterned surfaces are frequently exposed to plasmas as in plasma characterization through minuscule sampling orifices or in applications ranging from etching, deposition, and ashing in microelectronics, to selective surface functionalization. Frequently, the patterns consist of dissimilar materials (insulating masks, conductive metal or polysilicon, gate and field oxide), which charge up as a result of the directionality difference between ions and electrons at the plasma-sheath exit. Plasma-induced charging may cause ion deflection with undesirable consequences; for example, mask charging leads to sidewall profile irregularities when etching high aspect ratio features. In this proposal, we seek to reveal the fundamental physics of plasma-induced charging through a combined experimental and theoretical approach focused on dense sub-micron patterns of insulators and conductors similar to those encountered during plasma etching. Large-scale Monte Carlo simulation will combine sheath dynamics, microstructure charging, electrostatics, reactions, scattering, electron tunneling through t n insulators, and surface currents to shed light into a variety of conflicting reports on the influence of plasma parameters on charging damage. In particular, we seek to understand the nature of the so called "electron shading" damage, which causes catastrophic electron tunneling currents through the gate oxide in polysilicon-on-insulator structures. Significant modeling effort on pattern-dependent charging effects will be expanded to include tunneling effects and surface currents and will be used to predict:a) The influence of electron temperature, rf bias, and rf frequency on charging damage.b) Aspect-ratio-dependent charging effects. Is there a correlation between microloading and electron shadowing?c) Mask thickness effects. How will the use of thinner hard (oxide) masks impact charging damage?d) Feature- and wafer-scale effects. Does charging of a particular feature affect damage in neighboring trenches?e) Pulsed-plasma effects. Why do pulsed plasmas reduce both forms of charging damage? f) New device-layout rules for eliminating charging damage.The simulation results will be validated by extensive etching experiments in a high density plasma produced in a helical resonator