Fig. 5. (a) PDOS of Ag(T3), F and Si bonding with Ag(T3), (b) PDOS of Ag(HB), F and Si bonding with Ag(HB), (c) PDOS of Ag(T4), F and Si bonding with Ag(T4). The Fermi level BHQ set to zero energy.Figure optionsDownload full-size imageDownload as PowerPoint slide
In Fig. 6a–f, as Ag(T4) transferred F− one by one, the F− slipped to the adjacent Si and the bond length between the Si and F− extended gradually, indicating greater extraction of the Si from wafer. Finally, the Si bonding with 4 F− escaped from the wafer while the Ag(T4) still attached on the Si wafer ready for transferring next F− to Si. Besides, the electron density of F− and the Si (bonding with F−) also provided evidence that the interaction between the Si (bonding with F−) and the wafer became less and the bond length grew larger as the Si bonded with more F−. Additionally, SiF4 will bond with two more F− through hydrogen bond when dissolved into HF solution .