Chemical Treatment Effect of Si(111) Surfaces in H 2 SO 4 :H 2 O 2 Solution

Chemically treated Si(111) surfaces in an H 2 SO 4 :H 2 O 2 =4:1 (sulphuric peroxide mixture; SPM) solution at 80° C have been studied using spectroellipsometry (SE), ex situ atomic force microscopy (AFM) and contact-angle measurement techniques. The SE data clearly indicate that the solution causes in surface chemical oxidation. The oxidation occurs immediately upon immersing the sample in the solution. The thickness of the chemical oxide layer shows a nearly saturated value of ∼14 Å. The SE data also indicate that the chemical oxidation and subsequent HF etching result in surface smoothing, in reasonable agreement with the AFM results. The SPM-treated surface is found to be highly hydrophilic.