Electrical Properties of Polycrystalline Si_1-xGe_xThin-Films Prepared by a Solid-Phase Crystallization Method

Abstract

We studied the electrical properties of solid-phase-crystallized polycrystalline Si1-xGex films (SPC poly-Si1-xGex films) by combining Hall-effect measurement and a hydrogen plasma treatment method. In as-crystallized SPC poly-Si1-xGex films, the density of p-type states or defects increased with increasing Ge content. When the hydrogen plasma treatment was applied, the conductivity of the SPC poly-Si and -Ge films changed from p-type to n-type. However, in the SPC poly-Si1-xGex films, the conductivity did not change within our experimental hydrogen plasma treatment time. Because the results for phosphorous-doped SPC poly-Si1-xGex films were consistent with those for both SPC poly-Si and -Ge films, it was estimated that the SPC poly-Si1-xGex films contained numerous p-type states or defects that were not sensitively passivated by hydrogen plasma treatment. These results suggest that SPC poly-Si1-xGex films are preferable materials for low-cost and large electronic devices.