Study on electro plating and etching for metal interconnect in integrated circuit assisted with ArF excimer laser

本工作的目的是建立一种利用紫外激光辅助直接在硅片表面制作金属互连图形的技术。通过将UV激光照射在浸入工艺溶液中的晶片表面上，待照射的区域将被局部电镀或蚀刻。该工艺可实现集成电路金属互连图形的制作。目前，紫外激光照射可以增强局部刻蚀。不仅使用化学溶液，而且使用超纯水蚀刻晶片上的铜。当采用双紫外激光束曝光（λ= 193 nm，4 mJ/pulse ; 100 pulse/sec）时，在超纯水中的刻蚀速率为10 nm/min。该技术的主要问题是短波长紫外激光在工艺溶液中的透射和不同配混工艺溶液中增强或抑制的过程控制。

The aim of this work is to establish a technology which can fabricate metallic interconnection pattern directly on wafer surface by assisting with ultra violet laser irradiation. By irradiating the UV laser on the wafer surface dipped in process solution, the region to be irradiated would be locally plated or etched. This technique could realize the fabrication of metallic interconnection pattern used in integrated circuit. At present circumstance, UV laser irradiation can enhance the local etching. The copper on wafer was etched by not only use of the chemical solution, but also use of ultra pure water. The etching rate in ultra pure water was 10 nm/min, when applying the dual UV laser beam exposure (under the conditions of λ=193nm, 4mJ/pulse ; 100pulse/sec). Main issues of this technology are the transmissivity of the short wavelength of UV laser in process solutions and the process control of enhancement or inhibition in different compounding process solution.