ECLIPSE: Multiscale Modeling of Crossed-Field Discharges with Speed-Limited Particle-in-Cell Simulation

本项目旨在开发和演示优化等离子体磁控溅射的计算机模拟技术。 磁控溅射用于生产许多重要产品所必需的薄涂层，包括集成电路和太阳能电池。 磁控溅射装置通过使用高能离子将原子从阴极材料上敲出/溅射到基板上来涂覆基板材料。 改进这些设备将导致更可靠，更高质量的涂层，更低的生产成本和更高的性能-更便宜，更快的电子产品和更高效的太阳能电池板。改进的关键是控制溅射原子，这需要控制离子的密度、能量和分布。 通过该项目实现的计算机模拟将允许调查通过实验几乎无法访问的系统细节，以及更快地探索清洁能源技术的设计变化。 因此，该项目得到了ECosystem for Leading Innovation in Plasma Science and Engineering（ECLIPSE）计划的支持。阴极轰击离子在放电产生的等离子体中加速;磁场减少电子损失以维持等离子体。等离子体很难建模：它是非平衡的，部分电离的，适度碰撞的，在具有复杂几何形状的腔室中具有多个离子种类和等离子体-表面相互作用。粒子模拟（PIC）计算机模拟具有模拟所有这些效应的能力。然而，大量的计算成本对设计优化提出了严峻的挑战，这需要许多模拟来探索广泛的条件。在这个项目中，将开发和测试多种等离子体建模技术，以加快磁控溅射的PIC模拟，包括非均匀网格间距，节能PIC算法，允许网格单元大于等离子体德拜长度，以及速度限制PIC算法，它减少了完成模拟所需的时间步长。这些技术被认为是特别有效的，当一起使用时，他们将适用于广泛的低温等离子体模拟超越磁控溅射。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

This project aims to develop and demonstrate computer simulation techniques for optimizing plasma-based magnetron sputtering. Magnetron sputtering is used to produce thin coatings essential to many important products, including integrated circuits and solar cells. Magnetron sputtering devices coat a substrate material by using energetic ions to knock/sputter atoms off the cathode material and onto the substrate. Improving these devices will lead to more reliable, higher quality coatings, lower production costs, and increased performance - cheaper, faster electronics and more efficient solar panels. The key to improvement is controlling the sputtered atoms, which requires controlling the density, energy, and distribution of ions. Computer simulations enabled by this project will allow investigation of system details that are all but inaccessible via experiment, as well as faster exploration of design changes for clean energy technologies. As such, this project is being supported under the ECosystem for Leading Innovation in Plasma Science and Engineering (ECLIPSE) program.The cathode-bombarding ions are accelerated within a plasma produced by an electric discharge; a magnetic field reduces electron loss to maintain the plasma. The plasma is difficult to model: it is non-equilibrium, partially ionized, moderately collisional, with multiple ion species and plasma-surface interactions in a chamber with complicated geometry. Particle-in-cell (PIC) computer simulation has the power to simulate all these effects. However, the large computational cost poses severe challenges for design optimization, which requires many simulations to explore a wide range of conditions. In this project multiple plasma modeling techniques will be developed and tested to speed-up PIC simulation of magnetron sputtering, including non-uniform grid spacing, energy-conserving PIC algorithms that allow grid cells larger than the plasma Debye length, and the speed-limited PIC algorithm, which reduces the number of time steps needed to complete a simulation. These techniques are expected to be especially effective when used together, and they will be applicable to a wide range of low-temperature plasma simulations beyond magnetron sputtering.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.