氢气退火在UV-LIGA制作折叠波导慢波结构中的影响

Research on hydrogen annealing in UV-LIGA microfabrication of folded waveguide slow wave structures

摘要:

详细研究了利用紫外-光刻、电铸(UV-LIGA)技术制作全铜结构折叠波导各个阶段中氢气退火工艺对实验的影响。氢气退火工艺主要用于两个阶段：第一阶段为对铜基板的烧氢处理(前期)，第二阶段为实现金属结构后对基板和铸层整体的烧氢处理(后期)。实验发现，前期氢气退火除清洁基板、降低内应力外，还能发生晶界迁移，使晶粒在高温下生长趋于稳定，利于生长与之结合更紧密的电铸层。但该处理需提前至基板抛光之前，否则会导致平整度变差。后期氢气退火除检测全铜结构能否经受高温焊接外，还有助于进一步去除光刻胶，并促进基板和铸层在高温下生长为结合紧密的共同体。

Abstract:

The effect of hydrogen annealing in each stage of the production of all-copper structure folded waveguide by Ultraviolet-Lithographie Galvanoformung Abformung(UV-LIGA) is studied in detail. The hydrogen annealing step is in two stages, the first stage is the hydrogen treatment of the copper substrate(early stage), and the second stage is the treatment of the substrate and the electroformed layer after realizing the metal structure(later stage). Experiments show that in addition to cleaning the substrate and reducing the internal stress, hydrogen annealing in the early stage also migrates grain boundaries, so that the grain growth tends to be stable at high temperatures, which is conducive to the growth of the electroformed layer with better combination. However, this treatment needs to be advanced before the substrate is polished, otherwise the flatness will deteriorate. In addition to testing whether the all-copper structure can withstand high-temperature welding, hydrogen annealing in the later stage also helps to further remove the photoresist and promotes grain growth of substrate and electroformed layer as a whole at high temperature.