Mesoporous germanium formation by electrochemical etching

verfasst von

E. Garralaga Rojas, H. Plagwitz, B. Terheiden, J. Hensen, C. Baur, G. La Roche, G. F.X. Strobl, R. Brendel

Abstract

Uniform thick mesoporous germanium layers are reproducibly formed on 4 in. p-type Ge wafers by electrochemical etching in highly concentrated HF electrolytes. Pore formation by anodic etching in germanium leads to a constant dissolution of the porous layer. The growth rate of the porous Ge layer is therefore given by the difference between the etch rate at the porous layer/substrate wafer interface and the dissolution rate at the electrolyte/porous layer interface. The growth rate lies in the range of 0.071-2.7 nm/min for etching current densities of 0.1-80 mA/ cm², while both the etch rate and the dissolution rate lie in the range of several micrometers per minute. We define the substrate usage as the ratio of the growth rate and the etch rate. This substrate usage determines the growth efficiency of the porous layer and lies in the range of 0.2-2%. Thus, the substrate wafer is thinned substantially during anodic porous layer formation. Constantly alternating from an anodic to a cathodic bias prevents the thinning of the substrate. The dissolution rate decreases, and the usage increases up to 98%.

Externe Organisation(en)

Institut für Solarenergieforschung GmbH (ISFH)
Europäische Weltraumforschungs- und Technologiezentrum (ESTEC)
AZUR SPACE Solar Power GmbH

Typ

Artikel

Journal

Journal of the Electrochemical Society

Band

156

Seiten

D310-D313

ISSN

0013-4651

Publikationsdatum

2009

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Oberflächen, Beschichtungen und Folien, Elektrochemie, Werkstoffchemie

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.1149/1.3147271 (Zugang: Geschlossen)