Ortho and para interstitial H2 in silicon

Area of Science:

• Solid-state physics
• Materials science
• Spectroscopy

Background:

• Hydrogen (H2) and deuterium (D2) are crucial in semiconductor research.
• Understanding their behavior in silicon (Si) is key for device performance.
• Interstitial sites and nuclear-spin states influence material properties.

Purpose of the Study:

• To investigate H2 and D2 trapped at interstitial T sites in silicon using Raman scattering.
• To observe and analyze the different nuclear-spin states (ortho and para) of H2 and D2.
• To understand the stability and potential degradation mechanisms of these hydrogen isotopes in silicon.

Main Methods:

• Raman scattering spectroscopy was employed to study H2 and D2 in silicon.
• Observation of both ortho and para nuclear-spin states for H2 and D2.
• Analysis of spectral changes under laser excitation and room temperature storage.

Main Results:

• Both ortho and para nuclear-spin states of H2 and D2 were successfully observed.
• Raman signals for the J=0 rotational state of H2 and D2 preferentially disappeared.
• Signal loss occurred during laser excitation and prolonged dark storage at room temperature.

Conclusions:

• The disappearance of J=0 state signals suggests a dynamic process affecting these specific states.
• Tentative explanation involves differing diffusion rates between the J=0 and J=1 rotational states of H2.
• Further research is needed to confirm diffusion mechanisms and their impact on silicon.