Hydrogen molecules and hydrogen-related defects in crystalline silicon

Abstract

We have found that hydrogen exists in molecular form in crystalline silicon treated with hydrogen atoms in the downstream of a hydrogen plasma. The vibrational Raman line of hydrogen molecules is observed at 4158 cm Ϫ1 for silicon samples hydrogenated between 180 and 500°C. The assignment of the Raman line is confirmed by its isotope shift to 2990 cm Ϫ1 for silicon treated with deuterium atoms. The Raman intensity has a maximum for hydrogenation at 400°C. The vibrational Raman line of the hydrogen molecules is broad and asymmetric. It consists of at least two components, possibly arising from hydrogen molecules in different occupation sites in crystalline silicon. The rotational Raman line of hydrogen molecules is observed at 590 cm Ϫ1 . The Raman band of Si-H stretching is observed for hydrogenation temperatures between 100 and 500°C and the intensity has a maximum for hydrogenation at 250°C. ͓S0163-1829͑97͒09235-7͔

Formation of hydrogen-boron complexes in boron-doped silicon treated with a high concentration of hydrogen atoms

“…Here, the peak at 2105 cm −1 is the Si-H stretching mode of platelets. 15,16 On the other hand, the frequency ratios of the remaining peaks at 2283, 2387, and 2470 cm −1 to those at 1694, 1771, and 1854 cm −1 , respectively, are about 1.33-1.35. These values are too low to be within the range of the values for the Si-H bonds.…”

“…This is due to the fact that the frequency of platelets strongly depends on the hydrogenation temperature. 16 The results of the isotope shifts are summarized in Table I. Figure 3 shows the dependence of the Raman peaks related to B-H complexes on the concentration of B for specimens hydrogenated at two different temperatures: 165°C and 245°C.…”

“…After annihilation of the H-B passivation centers, various peaks appear with increasing hydrogenation temperature. The concentration of hydrogen introduced into specimens increases with increasing hydrogenation temperature, 16 resulting in the formation of complicated complexes with H such as B-H complexes and platelets. The intensities of the B-H stretching peaks at 2283 and 2470 cm −1 show a similar dependence on hydrogenation temperature to those of the Si-H stretching peaks observed at 1931, 2222, and 2241 cm −1 .…”

“…6 Hydrogen passivation of B in Si is very efficient because the Coulomb attraction between interstitial H + and B − results in a very large capture radius. 7 Thus, almost all B in Si can be passivated by H. 8,9 With increasing concentration of H, hydrogen molecules [10][11][12][13][14] and extended planar defects called platelets 9,15,16 are formed. Furthermore, additional H-͓or deuterium ͑D͔͒ related Raman peaks are observed in the range of 1900-2300 ͑1300-1700͒ cm −1 .…”

Formation of low-resistivity region in p-Si substrate of SiGe/Si episystem by remote-hydrogen plasma treatment

“…Hydrogen gas of 40 sccm flowed in this tube and hydrogen plasma was operated in a microwave cavity with an injection power of 50 W. Samples were laid parallel to the gas flow approximately 20 cm apart downstream from the cavity. In order to supply more hydrogen atoms to the sample [8,9], water vapor of 2.0 sccm was mixed in the hydrogen gas. This treatment was performed after beveling the samples for the SR measurement in their as-grown state.…”