Oxidation of Germanium and Silicon surfaces (100): a comparative study through DFT methodology

Abstract

Density Functional Theory calculations are used to map out the preferential oxygen molecule adsorption sites and oxygen atom incorporation on germanium (100) surface. A comparison with primary oxidation mechanisms encountered in pure silicon and silicon germanium (100) surfaces is presented here. This study highlights opposite substrates behaviors facing oxygen molecule adsorption: 1/ surface germanium atoms move from their crystalline positions to adapt to the approaching oxygen molecule resulting in adsorbed peroxide bridge configuration, whereas oxygen molecule is fully dissociated in strand configuration on a silicon surface 2/ oxygen atoms tend to avoid each other on germanium surface whereas oxide nucleus can be observed on silicon surface even at the early steps of the oxidation process. Results show that germanium surface appears to be less reactive than the silicon substrate towards molecular oxygen species.

Thermally Activated Reactions of Phenol at the Ge(100)-2 × 1 Surface

“…Also, although structures with further subsurface migration of O were attempted by DFT calculations, no structure with additional stability compared to the state V could be located, possibly due to the low reactivity of the Ge substrate toward oxidation. 31,32…”

“…Therefore, it can be understood that new bonds are formed along with the breakage of similarly stable bonds, and thus the magnitude of the overall energy change accompanying thermal reaction of phenoxy/Ge(100) is small. Also, although structures with further subsurface migration of O were attempted by DFT calculations, no structure with additional stability compared to the state V could be located, possibly due to the low reactivity of the Ge substrate toward oxidation. , …”

Thermally Stable and Electrically Conductive, Vertically Aligned Carbon Nanotube/Silicon Infiltrated Composite Structures for High-Temperature Electrodes

“…Compared to the VACNT/Si composites without oxidation, the electrical conductivity slightly decreased after being oxidized at 600 °C, decreased by one magnitude after being oxidized at 700 °C, and dropped significantly over 800 °C. It is considered that, after oxidation treatment, the silicon on the VACNT/Si surface was oxidized but the oxidation is greatly slowed down beneath the VACNT/Si surface. , The formed thin silicon oxide layer affected the measurements significantly by increasing the contact resistance between the sample and the electrode, which thus led to the decrease in the measured electrical conductivity.…”

“…It is considered that, after oxidation treatment, the silicon on the VACNT/Si surface was oxidized but the oxidation is greatly slowed down beneath the VACNT/Si surface. 50,51 The formed thin silicon oxide layer affected the measurements significantly by increasing the contact resistance between the sample and the electrode, which thus led to the decrease in the measured electrical conductivity.…”

Integrated films of transition metal oxides for information technology

“…We owe to DFT our understanding of the perovskite/diamond-type interface beginning with the knowledge of its atomic structure [27][28][29][30][31][32]. The fundamental role of the Zintl template to prevent the oxidation of Si has been elucidated through first principles calculations [33][34][35][36][37][38][39][40][41][42][43][44][45]. The exact atomic positions of the interfacial Zintl layer are crucial for determining the correct band offsets of the interface.…”