Scanning tunneling microscopy observation of hydrogen-terminated Si(001) surfaces after rinsing in ultrapure water with low dissolved oxygen concentration

Scanning tunneling microscopy (STM) observations have been employed to obse rve hydrogen-terminated Si(001) surfaces prepared by rinsing in ultrapure w ater (UPW) with very low dissolved oxygen (DO) after removal of the native oxide using 1% HF acid at room temperature. Domed-shaped protrusions with h eight in nanometers, hut-shaped clusters parallel to the [110], and terrace s parallel to the Si(001) surfaces were observed on the UPW-treated surface s. The shape of the protrusions emerge even after 30 min rinsing and the ro ughness of the Si(001) surface increased with increasing duration of UPW ri nsing. The morphology variation due to the rinsing is consistent with the r esults obtained from attenuated-total-reflectance Fourier-transmittance inf rared (ATR-FT-IR) measurement. (C) 1999 Elsevier Science B.V. All rights re served.