Novel approach based on continuous trench modelling to predict focused ion beam prepared freeform surfaces
Novel approach based on continuous trench modelling to predict focused ion beam prepared freeform surfaces
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DOI：
10.1016/j.jmatprotec.2017.10.024
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发表时间：
2018-02
影响因子：
6.3
通讯作者：
A. Bilbao-Guillerna;R. T. Eachambadi;G. Cadot;D. Axinte;J. Billingham;F. Stumpf;S. Beuer;M. Rommel
中科院分区：
文献类型：
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作者：
A. Bilbao-Guillerna;R. T. Eachambadi;G. Cadot;D. Axinte;J. Billingham;F. Stumpf;S. Beuer;M. Rommel
聚焦离子束 (FIB) 系统可用于在固体表面上生成受控的微米和纳米特征。以这种方式制造的表面的预测需要了解目标材料的去除率，以便模拟表面的演变。在本文中，我们提出了该过程的连续时间模型，使我们能够预测 FIB 作用下沟槽和自由曲面的形状。当描述光束离散轨迹的点（连接连续停留点的线）足够接近以至于表面上生成的凹坑重叠时，这种类型的模型是合适的。在停留时间恒定的直光束路径的情况下，在这些条件下会生成均匀深度的沟槽。这种简化的方法大大减少了模拟过程所需的计算时间，而不会显着降低预测表面的准确性。针对特定 FIB 设置和工件的模型校准仅涉及少量实验。该模型的预测已在单晶硼 p 掺杂硅靶材料上针对几种不同的光束路径进行了测试。具有恒定停留时间的单个和重叠沟槽的横截面的深度和形状可以高精度预测。该模型还用于预测三个自由曲面，其中驻留时间沿光束路径的每条线变化。原子力显微镜形貌测量表明，测量轮廓和模拟轮廓之间的平均相对误差为 2-10%，具体取决于加工表面的复杂性。
Focused Ion Beam (FIB) systems can be used to generate controlled micro- and nano-features on a solid surface. Prediction of surfaces fabricated in this way requires knowledge of the rate of removal of the target material in order to simulate the evolution of the surface. In this paper we present a continuous-time model of this process that allows us to predict the shape of trenches and freeform surfaces under the action of FIB. This type of model is appropriate when the points that describe the discrete trajectory of the beam (the line connecting consecutive dwell points) are close enough that the craters generated on the surface overlap. In the case of a straight beam path with constant dwell time, a trench of uniform depth is generated under these conditions. This simplified approach considerably reduces the computing time needed to simulate the process, without significantly reducing the accuracy of the predicted surface. Calibration of the model for a particular FIB setup and workpiece involves only a small number of experimental trials. The predictions of the model have been tested on a single crystalline Boron p-doped Si target material for several different beam paths. The depth and shape of the cross section of single and overlapping trenches with constant dwell time are predicted with high accuracy. The model was also used to predict three freeform surfaces, where the dwell time varies along each line of the beam path. Atomic force microscopy topography measurements show that the average relative error between the measured and simulated profiles is 2–10% depending on the complexity of the machined surface.