窄间隙介质阻挡放电清除硅片表面颗粒污染物

Elimination of the Particle Pollutants on the Surface of Silicon Wafer by Narrow Gap Dielectric Barrier Discharge

硅片清洗技术已成为制备高技术电子产品的关键技术。采用窄间隙介质阻挡放电方法研制了低温氧等离子体源,把氧离解、电离、离解电离成O、O-、O+和O2(a1Δg)等低温氧等离子体,其中O-和O2(a1Δg)活性粒子进一步反应形成高质量浓度臭氧气体,再溶于酸性超净水中,用于去除硅片表面颗粒污染物。实验结果表明:当等离子体源输入功率为300 W时,臭氧气体质量浓度最高为316 mg/L;高质量浓度臭氧气体溶于pH值为3.8的超净水中形成臭氧超净水,质量浓度为62.4 mg/L;在硅片清洗槽内,高质量浓度臭氧超净水仅用30 s就可去除硅片表面的Cu、Fe、Ca、Ni和Ti等金属颗粒物,去除率分别为98.4%、95.2%、88.4%、85.2%和64.1%。本方法与目前普遍使用的RCA清洗法相比,具有无需大剂量化学试剂和多种液体化学品、清洗工艺简单、投资及运行成本低等优势。因此,窄间隙介质阻挡放电清洗硅片表面颗粒污染物技术具有广阔的市场应用前景。

Silicon wafer cleaning technology has become a key technology in the preparation of high technology electronic products.The low-temperature oxygen plasma source was developed with the narrow gap dielectric barrier discharge method.Oxygen was dissociated,ionized and dissociatively ionized into the low-temperature oxygen plasmas,such as O,O-,O+and O2(a1Δg),among which O-further reacted with O2(a1Δg)active particles,forming the ozone gas with a high mass concentration,and then the ozone gas dissolved in the acid ultra-clean water to remove particulate pollutants on the surface of the silicon wafer.The experimental results show that when the input power of the plasma source is 300 W,the maximum mass concentration of the ozone gas is 316 mg/L.The high mass concentration ozone gas dissolves in the ultra-clean water with a pH value of 3.8 to form the ozone ultra-clean water,and the mass fraction of which is 62.4 mg/L.The high mass concentration ozone ultra-clean water in the silicon wafer cleaning tank can remove metal particles(such as Cu,Fe,Ca,Ni,Ti and other metallic particles)on the surface of the silicon wafer in only 30 s,and the remove rates are 98.4%,95.2%,88.4%,85.2%and 64.1%,respectively.Compared with the current commonly used RCA cleaning method,the cleaning method has the advantages of no need for large doses of chemical reagents and multiple liquid chemicals,simple cleaning process,and low investment and operating costs.Therefore,the technology of narrow gap dielectric barrier discharge method of cleaning the particles on the silicon surface has a broad market application prospect.