Hydrogen termination anodic dissolution

The surface of silicon during anodic dissolution is dynamically terminated by hydrogen the dissolution of silicon atoms proceeds by first forming a Si-H bond. 

The data presented in the following section concern only the hydrogen reaction at cathodic potentials. Those on hydrogen termination are presented in Chapter 2 and on silicon dissolution in Chapter 5. It is to be noted that as a reduction reaction, hydrogen evolution has not been well investigated at cathodic potentials although it has been the subject of numerous studies on the phenomena at anodic or open-circuit potentials. 

Reaction (5.12) results in Hz evolution which is of chemical nature and is responsible for the effective dissolution valence of 2. The Turner-Memming model explains the overall characteristics of the anodic reactions, that is, two different reaction paths in HF and in non-HF solutions passivation by an oxide film at high anodic potentials evolution of hydrogen to account for the effective dissolution valence being less than 4. However, it lacks the details to account for phenomena such as surface termination by hydrogen, current multiplication, and variation of effective dissolution valence. 

Evolution of hydrogen gas occurs during the formation of PS. It is the result of the chemical reaction responsible for the effective dissolution valence of less than 4. Figure 8.11 shows that the amount of hydrogen gas is proportional to the time of anodization. When the anodization is stopped, the hydrogen evolution still continues at a lower rate. In situ F TIR studies indicate that the H-termination of the silicon surface is preserved during PS formation on The silicon atoms on the surface are... 

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