Cleaning method using ozone-deionized ultra-pure water and hydrofluoric acid solution during semiconductor element cleaning process

摘要

The present invention is a cleaning method using DI water (deionized water) and HF (hydrofluoric acid) solution blowing O ₃ (ozone) among wet cleaning technologies most widely used in semiconductor cleaning technology. A summary of the technique of the present invention is as follows. First, as a pretreatment, piranha cleaning (H ₂ SO ₄ (sulfuric acid) + H ₂ O ₂ (hydrogen peroxide solution), ratio 4: 1, time 10 minutes, temperature 120 (HF (hydrofluoric acid) + H ₂ O, ratio 1: 100, cleaning time 5 minutes, room temperature). Then, the specimen treated as above was immersed in 1 ppm CuSO ₄ (copper sulfate) standard solution to contaminate Cu (copper) as metal impurities on the substrate. The contaminated specimens were washed with DI water (O ₃ ) (HF (fluoric acid) + H ₂ O, ratio 1: 100, cleaning time 5 minutes) and Cu (copper) metal The effect of removing impurities and the roughness of the Si (silicon) substrate surface were investigated. The present invention is based on the most commonly used solutions, such as DI water (deionized water) or HF (hydrofluoric acid) solution, in order to be easily applied to a conventional wet cleaning method during the semiconductor production cleaning process, and O ₃ (ozone) To increase the cleaning effect and to appropriately combine and repeatedly test the two solutions to show that it is a cleaning method which is effective for the removal of metal impurities and the surface roughness of the substrate. As a result, the contaminated copper impurities were greatly reduced to the level of 10 ¹³ to 10 ¹⁰ atoms / ㎠ and the roughness of the surface was doubled.