The presence of Si-H bonds in hydrogen FZ silicon single crystals was confirmed by measurements of infrared absorption spectrum. Three characteristic absorption peaks were found at 4.51, 4.68 and 5.13 μm. By analysing theoretical calculations, it is believed that hydrogen atoms in silicon lattice are situated on several interstitial sites. Investigation showed that the Si-H bonds formed in crystal growth influences implicitly on the crystal perfection, and it was discovered that there exists a close relationship between the production, of defects by hydrogen and the breakdown of hydrogen-associated bonds at high temperature.