Transformation of germanium to fluogermanates
Artikel i vetenskaplig tidskrift, 2010

The surface of a single-crystal germanium wafer was transformed to crystals of germanium fluorides and oxides upon exposure to a vapor of HF and HNO3 chemical mixture. Structure analysis indicates that the transformation results in a germanate polycrystalline layer consisting of germanium oxide and ammonium fluogermanate with preferential crystal growth orientation in aOE (c) 101 > direction. Local vibrational mode analysis confirms the presence of N-H and Ge-F vibrational modes in addition to Ge-O stretching modes. Energy dispersive studies reveal the presence of hexagonal alpha-phase GeO2 crystal clusters and ammonium fluogermanates around these clusters in addition to a surface oxide layer. Electronic band structure as probed by ellipsometry has been associated with the germanium oxide crystals and disorder-induced band tailing effects at the interface of the germanate layer and the bulk Ge wafer. The acid vapor exposure causes Ge surface to emit yellow photoluminescence at room temperature.


S. Kalem

Turkiye Bilimsel ve Teknolojik Arastirma Kurumu

Örjan Arthursson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Nanotekniklaboratoriet

I. Romandic


Applied Physics A: Materials Science and Processing

0947-8396 (ISSN) 1432-0630 (eISSN)

Vol. 98 423-428