Anisotropic magnetic centers and conduction electrons in hydrogenated microcrystalline silicon

Electron spin resonance of anisotropic magnetic centers (dangling bonds) and conduction electrons in hydrogenated microcrystalline silicon (μc-Si:H) prepared by plasma-enhanced chemical vapor deposition (PECVD) has been observed at room temperature. The anisotropic g-shifts of dangling bonds in μc-Si:H are discussed in terms of tight-binding approaches and in comparison with those of dangling bonds in μc-Si:H prepared by hot-wire CVD and hydrogenated amorphous silicon (a-Si:H), Pb centers at the Si–SiO2 interface and defects in crystalline silicon (c-Si). The spin densities of anisotropic magnetic centers and conduction electrons were measured as a function of gas-dilution ratio of SiH4 into H2 in mixture gas used in PECVD and are discussed.