Author:

Keywords:

amorphous silicon, defects, passivation, capacitance, spin resonance, M interface/bulk defects, Science & Technology, Technology, Physical Sciences, Energy & Fuels, Materials Science, Multidisciplinary, Physics, Applied, Materials Science, Physics, 0904 Chemical Engineering, 0906 Electrical and Electronic Engineering

Abstract:

In this work, an extensive characterisation of intrinsic amorphous silicon (a-Si) passivation layers deposited on n- and p-type silicon is reported. Low temperature capacitance-voltage measurements are utilised to enable parameter extraction from the c-Si/a-Si interface and a-Si bulk. Electron spin resonance enables atomic identification of defects present. Results reveal the presence of electrically active defects at the c-Si/intrinsic a-Si interface (∼1×1012 cm-2), and throughout the amorphous silicon layer bulk (∼8×1016 cm-3), which are atomically identified as Pb0 centres and D centres silicon dangling bond defects, respectively. The value of this work is the atomic identification of these defects in this stack, coupled with their electrical activity. That they can be detected by these techniques demonstrates the power of the methodology used to assess and quantify these defects. Therein lies the significance of this work: a methodology capable of fundamentally optimising amorphous silicon processing from an atomic perspective.