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C Gemmel; J Hensen; S Kajari-Schröder; R Brendel
Detachment yield statistics for kerfless wafering using the porous silicon process Artikel
In: Solar Energy Materials and Solar Cells, Bd. 202, S. 110061, 2019, ISSN: 0927-0248.
@article{Gemmel2019c,
title = {Detachment yield statistics for kerfless wafering using the porous silicon process},
author = {C Gemmel and J Hensen and S Kajari-Schröder and R Brendel},
doi = {10.1016/j.solmat.2019.110061},
issn = {0927-0248},
year = {2019},
date = {2019-11-01},
journal = {Solar Energy Materials and Solar Cells},
volume = {202},
pages = {110061},
abstract = {The porous silicon (PSI) process is a wafering method to fabricate high quality kerfless crystalline Si wafers by epitaxial wafer growth on porous Si and subsequent detachment from a reusable substrate wafer. The process yield is a key parameter for the economic viability of the PSI process. We experimentally demonstrate the detachment of 59 out of 62 PSI wafers with a size of 10 × 10 cm2, and separation layer etch current densities of 105–120 mA/cm2 for electrochemically etching the porous Si, and for substrate wafers with a resistivity of 15.7–16.9 mΩcm. We discuss the statistics of how to deduce a detachment probability from this. From our experiments, we determine a detachment yield of at least 88% with an error probability of 5%. The demonstration of a 99% detachment yield with an error probability of 5% would require at least 300 successfully detached wafers with no failed detachment. Samples have a minority carrier density ranging from 1 to 1.7 ms before any external gettering, which demonstrates the high electric quality of the PSI wafers.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The porous silicon (PSI) process is a wafering method to fabricate high quality kerfless crystalline Si wafers by epitaxial wafer growth on porous Si and subsequent detachment from a reusable substrate wafer. The process yield is a key parameter for the economic viability of the PSI process. We experimentally demonstrate the detachment of 59 out of 62 PSI wafers with a size of 10 × 10 cm2, and separation layer etch current densities of 105–120 mA/cm2 for electrochemically etching the porous Si, and for substrate wafers with a resistivity of 15.7–16.9 mΩcm. We discuss the statistics of how to deduce a detachment probability from this. From our experiments, we determine a detachment yield of at least 88% with an error probability of 5%. The demonstration of a 99% detachment yield with an error probability of 5% would require at least 300 successfully detached wafers with no failed detachment. Samples have a minority carrier density ranging from 1 to 1.7 ms before any external gettering, which demonstrates the high electric quality of the PSI wafers.