A pre-hydrogen glow method to improve the reproducibility of intrinsic microcrystalline silicon thin film depositions in a single-chamber system

Material property differences are observed in hydrogenated microcrystalline silicon (μc-Si:H) thin films deposited under the same nominal conditions in a single-chamber plasma enhanced chemical vapor deposition system but at different stages of chamber history during prolonged usage. This phenomenon is called system shift, which results from the increase of powder coverage on the surface of the cathode and the coatings on other areas in the chamber. We propose a pre-hydrogen glow method to suppress the system shifting. Experimental results show that this method is very effective to reduce the non-reproducibility in μc-Si:H depositions for prolonged usage of the deposition system. In addition, the μc-Si:H films deposited with the pre-hydrogen glow have an improved structural homogeneity along the film thickness.

Condition one, the chamber was mechanically cleaned before the depositions; condition two, the system had been used for 50 depositions of thin films and pin solar cells; and in condition three, the system had also been used for 50 depositions of thin films and pin solar cells, but a pre-hydrogen glow was used before the deposition of μc-Si:H films.Figure optionsDownload as PowerPoint slideHighlights
► Material property drift is observed in hydrogenated microcrystalline silicon.
► A pre-hydrogen glow method was proposed to suppress the shifting.
► Pre-hydrogen glow gives improved structural homogeneity along film thickness.