Abstract
In this thesis, we proposed a new advanced wet-chemical one-step cleaning process, which omits HPM step in RCA. A novel one-step cleaning solution had been developed for standard and pre-gate oxide cleaning to replace the conventional RCA two-sep cleaning recipe, which includes APM (or SC-1) and HPM (or SC-2) step. Tetra Methyl Ammonium Hydroxide (TMAH) and Ethylene Diamine Tetra Acetic acid (EDTA) were added into the RCA SC-1 cleaning solution to enhance cleaning efficiency. From the experimental results, the particle and metallic contaminations on the bare-Si wafer surface could be removed significantly by applying this novel one-step cleaning solution. The surface adsorption and double layer model could explain the surface behavior of TMAH solutions. Based on the model, the improvement on the particle, surface roughness and the metallic contaminants on the surface can be realized. It was observed that the electrical properties of MOSFET after cleaning with this novel solution were better than the conventional RCA cleaning. Besides, the cleaning method combining NH4OH, TMAH, EDTA and H2O2, at 60 °C for 5-min, shows the high performance on particle removal, metal cleaning, surface smoothness and electrical behavior. Hence, this novel one-step cleaning process is very promising for future large-size silicon wafer cleaning due to the advantages of time saving, cost down, and high performance.