ON THE NATURE OF THE PARAMAGNETIC DEFECTS IN HYDROGENATED AMORPHOUS-SILICON NITRIDE

ESR measurements in nitrogen-rich hydrogenated amorphous silicon nitri de (a-SiNx:H with x > 1.3) as a function of temperature and microwave power reveal a second paramagnetic center in addition to the well-know n, three-fold-coordinated silicon ''dangling bond'' (K center). This s econd center is a neutral, two-fold-coordinated nitrogen bonded to two silicon atoms (N-2(o) center). This discovery suggests that the domin ant defects in a-SiN1.6:H are compensated K-3(+) and N-2(-) electron a nd hole traps, respectively.