Abstract

Recently, research on the optical second- harmonic generation (SHG) from silicon surface has received much attention. Analysis of how SHG is affected by surface ordering and symmetry, as well as molecules adsorbed at the surface had led to a better understanding of silicon surface structure.¹ However, no parallel effort has been given to the study of the grain boundary structures in polycrystalline silicon (polysilicon), which has found vast applications in integrated-circuit (IC) technology.² Since grain boundaries in polysilicon are interfacial layers between two silicon grains with different crystal orientation, the mechanism governing SHG from grain boundaries is expected to be very similar to that for single crystal silicon surface. Thus, the study of SHG from polysilicon may shed light on the current understanding of grain boundary structures gained from electrical analysis. In this work, we investigate the reflected SHG from polysilicon and present some experimental results in an attempt to correlate the SHG effect with grain boundary structures.

© 1994 Optical Society of America