Properties of Hydrogen Species in n‐Type Silicon Deduced from In‐Diffusion Profiles

• Published in: Physica status solidi. A, Applications and materials science Vol. 221; no. 17
• Main Authors: Voronkov, Vladimir V., Falster, Robert
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.09.2024
• Subjects: Depth profiling; diffusion; Diffusivity; Dimers; donors; Hydrogen; Positive ions; Silicon; Species diffusion
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.202400360

Reported depth profiles of hydrogen in plasma‐exposed n‐Si samples can be fitted with a simple model of hydrogen transport by negative and neutral species (H− and H0) accompanied by a reversible formation of hydrogen–donor pairs (HD) and by an irreversible production of mobile dimers H2A—in particular by a bulk pairing reaction of the H− and H0 species. Contrary to a complicated behavior of hydrogen found in p‐Si (with multiple independent states for positive ions and passivated boron), the situation in n‐Si appears to be much simpler as only single states for H−, H0, and HD are sufficient for profile reproduction. The parameters deduced from the profiles are the diffusivity of H−, the characteristic electron concentration marking equal contributions of H− and H0 into hydrogen transport, and the diffusivity of H2A dimers (in the available temperature range 120–225 °C). Reported depth profiles of hydrogen (deuterium) in plasma‐exposed n‐Si samples have been fitted. Hydrogen transport is by negative (H−) and neutral (H0) species. Donors are partially passivated by H−. Mobile dimers H2A are produced by H0 + H− pairing. Some important parameters like the diffusivities of H− and of H2A are extracted.