太赫兹金属器件电铸工艺中电流密度研究

微电铸工艺是太赫兹全金属光栅器件成型的关键工序。金属光栅质量取决于电铸工艺中金属离子沉积的均匀性, 而电铸槽阴极附近电流密度的分布直接影响金属离子沉积的均匀性。在阳极与阴极间添加开孔的绝缘玻璃挡板可以改善阴极电流密度分布的均匀性, 研究了挡板与阴极的距离以及挡板开孔大小对阴极电流密度分布的影响, 仿真结果表明: 添加开孔绝缘挡板有助于改善阴极处的电流密度分布; 当添加的玻璃挡板开孔大小与阴极尺寸一致时, 挡板距离阴极越近, 阴极的电流密度分布越均匀。根据仿真结果设计了相应的挡板, 电铸工艺获得了较好质量的均匀金属层, 从而验证了上述仿真分析的有效性。

Study of current density distribution in terahertz device micro-electroforming process

Micro-electroforming is a key step of terahertz all-metal devices microfabrication, in which metal-ion deposit uniformity determines the grating's quality.Meanwhile, the deposit uniformity is influenced by the distribution of current density near the cathode.The current density distribution in copper micro-electroforming is investigated by method of FIT (finite integration technique) simulation analysis and experimental verification.By adding aglass baffle panel between anode and cathode, the current density uniformity can be improved.The effect of the distance between panel and cathode and the size of hole in baffle panel on current density uniformity is analyzed thoroughly.The nearer the panel is to the cathode, the more uniform the current density of the cathode, which can significantly improve the uniformity of deposit in microstructure.According to the simulation results, a baffle panel with a 2.5 cm×2.5 cm gap is fabricated and placed between the anode and the cathode with a 100 mm distance from the cathode.Then electroforming was carried out and a better quality metal layer with finer and more uniform grain was gained, which proved the simulation results.