Ion Energy Threshold in Low-Temperature Silicon Epitaxy for Thin-Film Crystalline Photovoltaics

• Published in: IEEE journal of photovoltaics Vol. 4; no. 6; pp. 1361 - 1367
• Main Authors: Bruneau, Bastien, Cariou, Romain, Dornstetter, Jean-Christophe, Lepecq, Michael, Maurice, Jean-Luc, Roca i Cabarrocas, Pere, Johnson, Erik V.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.11.2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Chemical vapor deposition; Crystalline materials; Diffraction; Epitaxial growth; Epitaxy; ion energy; low temperature; Plasma temperature; plasmaenhanced chemical vapor deposition (PECVD); Silicon; solar cells; tailored voltage waveform; tailored voltage waveform; silicon; Epitaxy; ion energy; solar cells; low temperature; plasma-enhanced chemical vapor deposition (PECVD)
• ISSN: 2156-3381; 2156-3403
• DOI: 10.1109/JPHOTOV.2014.2357256

Plasma-enhanced chemical vapor deposition (PECVD) enables epitaxial silicon deposition for up to several micrometers and at low temperatures (as low as 150 °C). We present herein a detailed study of the effect of ion energy at high (above 2 torr) and low (below 1 torr) pressure, where the plasma and surface reactions are expected to be different, i.e., driven, respectively, by high-order and low-order silane precursors. We find a sharp energy threshold at low pressure, above which no epitaxy can be obtained, but this threshold is relaxed at high pressure. The occurrence of epitaxy breakdown is studied and compared in detail for these two different pressure regimes.