Effect of Doping on the Electron Spin Resonance in Phosphorus Doped Silicon. III. Absorption Intensity

Absorption intensity of the electron spin resonance in phosphorus doped silicon was measured at room and liquid nitrogen temperatures by comparing with signal from the known amount of DPPH. Experimental conditions were devised so as to locate the silicon sample and DPPH at the position of RF magnetic field of the same strength. The absorption intensity was measured as a function of the electron or phosphorus concentration and compared with the theoretical calculation based on the paramagnetic susceptibility of conduction electrons. At room temperature, the observed intensity was found to agree quite well with the theoretical calculation, showing that the electron spin resonance originates from conduction electrons. At liquid nitrogen temperature, however, qualitative agreement with the theoretical calculation was found only at higher donor concentration.