Excellent passivation of thin silicon wafers by HF‐free hydrogen plasma etching using an industrial ICPECVD tool. Issue 1 (17th November 2014)

• Record Type: Journal Article
• Authors: Tang, Muzhi; Ge, Jia; Wong, Johnson; Ling, Zhi Peng; Dippell, Torsten; Zhang, Zhenhao; Huber, Marco; Doerr, Manfred; Hohn, Oliver; Wohlfart, Peter; Aberle, Armin Gerhard; Mueller, Thomas
• Is Part Of: Physica status solidi. Volume 9:Issue 1(2015:Jan.)
• Page Start: 47
• Page End: 52
• Publication Date: 2014-11-17
• Subjects: Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.201409333
• Languages: English
• ISSNs: 1862-6254

Abstract

<abstract abstract-type="main" id="pssr201409333-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>In this work, hydrogen plasma etching of surface oxides was successfully accomplished on thin (∼100 µm) planar n‐type Czochralski silicon wafers prior to intrinsic hydrogenated amorphous silicon [a‐Si:H(i)] deposition for heterojunction solar cells, using an industrial inductively coupled plasma‐enhanced chemical vapour deposition (ICPECVD) platform. The plasma etching process is intended as a dry alternative to the conventional wet‐chemical hydrofluoric acid (HF) dip for solar cell processing. After symmetrical deposition of an a‐Si:H(i) passivation layer, high effective carrier lifetimes of up to 3.7 ms are obtained, which are equivalent to effective surface recombination velocities of 1.3 cm s^–1 and an implied open‐circuit voltage (<italic>V</italic>_oc) of 741 mV. The passivation quality is excellent and comparable to other high quality a‐Si:H(i) passivation. High‐resolution transmission electron microscopy shows evidence of plasma‐silicon interactions and a sub‐nanometre interfacial layer. Using electron energy‐loss spectroscopy, this layer is further investigated and confirmed to be hydrogenated suboxide layers. (© 2015 WILEY‐VCH Verlag GmbH &amp;Co. KGaA, Weinheim)</p> </abstract>