First-principles study of hydrogen-enhanced phosphorus diffusion in silicon

Le The Anh, Nguyen Tien Cuong, Pham Tien Lam, Muruganathan Manoharan, Hiroshi Mizuta, Hideki Matsumura, Nobuo Otsuka, Dam Hieu Chi

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2 Citations (Scopus)

Abstract

We present a first-principles study on the interstitial-mediated diffusion process of neutral phosphorus (P) atoms in a silicon crystal with the presence of mono-atomic hydrogen (H). By relaxing initial Si structures containing a P atom and an H atom, we derived four low-energy P-H-Si defect complexes whose formation energies are significantly lower than those of P-Si defect complexes. These four defect complexes are classified into two groups. In group A, an H atom is located near a Si atom, whereas in group B, an H atom is close to a P atom. We found that the H atom pairs with P or Si atom and changes the nature bonding between P and Si atoms from out-of-phase conjugation to in-phase conjugation. This fact results in the lower formation energies compare to the cases without H atom. For the migration of defect complexes, we have found that P-H-Si defect complexes can migrate with low barrier energies if an H atom sticks to either P or Si atom. Group B complexes can migrate from one lattice site to another with an H atom staying close to a P atom. Group A complexes cannot migrate from one lattice site to another without a transfer of an H atom from one Si atom to another Si atom. A change in the structure of defect complexes between groups A and B during the migration results in a transfer of an H atom between P and Si atoms. The results for diffusion of group B complexes show that the presence of mono-atomic H significantly reduces the activation energy of P diffusion in a Si crystal, which is considered as a summation of formation energy and migration barrier energy, leading to the enhancement of diffusion of P atoms at low temperatures, which has been suggested by recent experimental studies.

Original languageEnglish
Article number045703
JournalJournal of Applied Physics
Volume119
Issue number4
DOIs
Publication statusPublished - 2016 Jan 28
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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