1.
P Jäger; V Mertens; U Baumann; T Dullweber
In: IEEE Journal of Photovoltaics, Bd. 11, Nr. 1, S. 50-57, 2021.
@article{Jäger2020c,
title = {A Detailed Chemical Model for the Diffusion of Phosphorus Into the Silicon Wafer During POCl3 Diffusion},
author = {P Jäger and V Mertens and U Baumann and T Dullweber},
doi = {10.1109/JPHOTOV.2020.3038331},
year = {2021},
date = {2021-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {11},
number = {1},
pages = {50-57},
abstract = {The POCl 3 diffusion is the main technology to form the p-n junction of industrial silicon solar cells. However, the diffusion mechanism of phosphorus (P) into the silicon wafer is not fully understood. In this article, we study the P diffusion mechanism during drive-in by systematically varying the drive-in time in the oxygen (O 2 ) atmosphere and subsequently in nitrogen (N 2 ). When increasing the drive-in time in O 2 from 0 to 120 min, the sheet resistance R sheet stays constant at 485±30 Ω/sq. Hence, we demonstrate for the first time that the phosphorus diffusion can be completely suppressed in the O 2 atmosphere. When adding a drive-in in the N 2 atmosphere directly after the drive-in in O 2 , we find that the SiO 2 thickness d SiO2,O2 changes from initially 2 to 10 nm after O 2 drive-in to an equilibrium SiO 2 thickness d SiO2,eq of 4.7 nm after N 2 drive-in. We prove for the first time that if d SiO2,O2 > d SiO2,eq , no P diffuses into the silicon wafer even in the N 2 atmosphere. Only if d SiO2,O2 < d SiO2,eq , phosphorus diffuses into the silicon wafer in the N 2 atmosphere. We propose a detailed chemical model to explain our experimental results, which assumes that the diffusion of Si from the wafer through the SiO 2 interface toward the PSG plays a key role. In this model, P can only diffuse into the Si wafer if P 2 O 5 in the PSG is reduced by the Si from the wafer to P and SiO 2 .},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The POCl 3 diffusion is the main technology to form the p-n junction of industrial silicon solar cells. However, the diffusion mechanism of phosphorus (P) into the silicon wafer is not fully understood. In this article, we study the P diffusion mechanism during drive-in by systematically varying the drive-in time in the oxygen (O 2 ) atmosphere and subsequently in nitrogen (N 2 ). When increasing the drive-in time in O 2 from 0 to 120 min, the sheet resistance R sheet stays constant at 485±30 Ω/sq. Hence, we demonstrate for the first time that the phosphorus diffusion can be completely suppressed in the O 2 atmosphere. When adding a drive-in in the N 2 atmosphere directly after the drive-in in O 2 , we find that the SiO 2 thickness d SiO2,O2 changes from initially 2 to 10 nm after O 2 drive-in to an equilibrium SiO 2 thickness d SiO2,eq of 4.7 nm after N 2 drive-in. We prove for the first time that if d SiO2,O2 > d SiO2,eq , no P diffuses into the silicon wafer even in the N 2 atmosphere. Only if d SiO2,O2 < d SiO2,eq , phosphorus diffuses into the silicon wafer in the N 2 atmosphere. We propose a detailed chemical model to explain our experimental results, which assumes that the diffusion of Si from the wafer through the SiO 2 interface toward the PSG plays a key role. In this model, P can only diffuse into the Si wafer if P 2 O 5 in the PSG is reduced by the Si from the wafer to P and SiO 2 .
2.
M Müller; P P Altermatt; K Schlegel; G Fischer
A Method for Imaging the Emitter Saturation Current With Lateral Resolution Artikel
In: IEEE Journal of Photovoltaics, Bd. 2, Nr. 4, S. 586-588, 2012, ISSN: 2156-3381.
@article{Müller2012e,
title = {A Method for Imaging the Emitter Saturation Current With Lateral Resolution},
author = {M Müller and P P Altermatt and K Schlegel and G Fischer},
doi = {10.1109/JPHOTOV.2012.2195552},
issn = {2156-3381},
year = {2012},
date = {2012-10-01},
journal = {IEEE Journal of Photovoltaics},
volume = {2},
number = {4},
pages = {586-588},
keywords = {},
pubstate = {published},
tppubtype = {article}
}