通过添加表面活性剂和螯合剂改进硅片化学清洗工艺的研究

Improvement of Silicon Wafer Wet Chemical Cleaning Process by Adding Surfactant and Chelating Agent

摘要:

通过在传统RCA清洗法所用的SC-1液中, 添加表面活性剂四甲基氢氧化铵(TMAH)和/或螯合剂乙二胺四乙酸(EDTA), 实验比较了不同清洗方法对颗粒粘污、金属粘污的去除效率;并测试了其对硅片表面粗糙度的影响。用MOS电容结构的击穿电场强度Weibull分布, 评价了不同清洗方法所得氧化层的质量。结果表明, 上述改进能够显著提高对颗粒粘污和金属粘污的去除效果, 同时能省去RCA的SC-2清洗步骤, 具有节省工时、化学试剂消耗量小的优势。

Abstract:

Adding surfactant tetramethylammonium hydroxide (TMAH) and chelating agent ethylenediaminetetraacetic acid (EDTA) into the SC-1 cleaning solution used in conventional RCA cleaning process, the removal efficiency of various cleaning recipes on particles and metallic impurities was analyzed, and their effects on the surface roughness of silicon wafer were measured. The Weibull distribution of breakdown electric field intensity of MOS capacitors was used to evaluate the electrical properties of the oxide films cleaned with various recipes. The experimental results indicate that the particles and metallic contamination on the bare Si wafer surface can be removed significantly by using this optimized cleaning solution with less time and lower cost.