单晶圆湿法清洗工艺中铝金属腐蚀问题研究

Aluminum Corrosion Issue Research in Wet Cleaning Process of Single Wafers

在集成电路制造中,湿法清洗工艺中铝金属腐蚀是一种致命缺陷,它的出现将引发产品的可靠性问题。通过控制清洗过程中的工艺参数,增加起侧壁保护作用的铝金属氧化层的厚度,从而抑制铝金属腐蚀缺陷的产生。随着清洗溶液温度的降低,晶圆清洗后6 h铝金属腐蚀缺陷数量明显减少;随着H_(2)SO_(4)标称质量分数由80%增加到105%,铝金属腐蚀缺陷数量减少;而H_(2)SO_(4)标称质量分数继续增加到115%时,铝金属腐蚀缺陷数量却增加。清洗溶液温度和H_(2)SO_(4)质量分数实验结果表明,更低的温度以及一定范围内的高H_(2)SO_(4)质量分数有利于促进铝金属氧化层的生成,强化侧壁保护,从而达到抑制铝金属腐蚀缺陷发生的目的。

Aluminum corrosion in wet cleaning process is a fatal defect during integrated circuit(IC)manufacturing,which leads to the problem of product reliability.By controlling the process para-meters in the cleaning process,the thickness of aluminum oxide layer which can protect the side wall is increased,and the aluminum corrosion defect can be suppressed.With the decrease of cleaning solution temperature,the amount of aluminum corrosion defect decreases obviously after 6 h of wafer cleaning.As the nominal mass fraction of H_(2)SO_(4)increases from 80% to 105%,the amount of aluminum corrosion defect decreases.However,when the nominal mass fraction of H_(2)SO_(4)continues to increase to 115%,the amount of aluminum corrosion defect increases.The experimental results of cleaning solution temperature and H_(2)SO_(4)mass fraction show that lower temperature and higher H_(2)SO_(4)mass fraction within a certain range are beneficial to premote the formation of aluminum oxide layer,and strengthen the side wall protection,so that the defect of aluminum corrosion is inhibited.