The effectiveness of HCl and HF cleaning of Si0.85Ge0.15 surface

Abstract

The cleaning of Si 0.85 Ge 0.15 surfaces using HCl and HF solutions is studied using synchrotron radiation photoelectron spectroscopy. The HF solution is found to be effective in removing both the Si oxide and the Ge oxide while the HCl solution can only remove part of the Ge oxide. For samples treated with HF, four spectral components are needed to fit the Ge 3d photoemission spectra. One is the bulk component and the other three are attributed to the surface Ge atoms with mono-hydride, di-hydride and trihydride terminations, respectively.

Corrosion of a 75Sn/25Pb coating on a low carbon steel in a gaseous environment polluted with HCl: mechanism

“…Consequently, the coating type can be exposed to very corrosive medium such as hydrogen chloride or hydrochloric acid. In fact acid solutions are widely used in the industry by the cleaning, pickling, or wastewater treatment . The household refuse incineration, the combustion of coal and several industrial activities can also lead to the formation of corrosive products.…”

Combined wet and dry cleaning of SiGe(001)

“…21 It is expected that the H termination is desorbed for the 500 C anneal as shown in previous reports. 16,30 In the absence of strong adsorbate bonding, the surface of SiGe(001) is terminated by Ge atoms due to the segregation of Ge to the surface as reported in the previous studies. [31][32][33] Density functional theory calculations theoretically verified that clean SiGe(001) surfaces are thermodynamically more stable when composed of Ge atoms compared to Si atoms.…”

“…Wet cleaning Si 0.6 Ge 0.4 (001) surfaces were cleaned via a 2% HF solution method leaving the surface hydrogen terminated at room temperature as reported in a previous study using synchrotron radiation photoelectron spectroscopy. 16 Figure 1(a) shows XPS results of SiGe(001) surface after 100, 200, and 500 C anneals. All XPS peaks are normalized by photoelectron cross-sections (Si2p-0.817, Ge 3d-1.42, O 1s-2.93, C 1s-1) using Hartree-Slater atomic model.…”

“…48 After atomic H dose, the Ge 2p peak is shifted to higher binding energy by 0.3 eV from a sputter cleaned SiGe(001) surface mainly due to the hydrogen termination at the surface as shown in the previous study. 16 After 500 C annealing, the Ge 2p peak is shifted back by 0.3-1217.4 eV binding energy since hydrogen atoms are desorbed and no adsorbates are present. Positions of peaks after each experimental step are compiled in Table IV. FIG.…”

“…HCl solution cleaning is an ineffective method to remove native oxide because SiO 2 is inert to HCl solutions. 16 Hydrofluoric acid (HF) treatment removes all the surface oxides, leaving the surface hydrogen terminated after transfer to UHV as shown by synchrotron high resolution x-ray photoelectron spectroscopy (XPS); however, an inert processing environment is required to avoid oxygen and carbon contamination since the hydrogen passivated Si(001) and Ge(001) surfaces after HF cleaning are not stable in the ambient air. [17][18][19] It is expected that GeH x species are less stable than SiH x species in ambient due to their weaker bonds.…”