TY  - JOUR
AU  - Loo, Roger
AU  - Shimura, Yosuke
AU  - Ike, Shinichi
AU  - Vohra, Anurag
AU  - Stoica, Toma
AU  - Stange, Daniela
AU  - Buca, Dan Mihai
AU  - Kohen, David
AU  - Margetis, Joe
AU  - Tolle, John
TI  - Epitaxial GeSn: impact of process conditions on material quality
JO  - Semiconductor science and technology
VL  - 33
IS  - 11
SN  - 0268-1242
CY  - Bristol
PB  - IOP Publ.
M1  - FZJ-2018-05908
SP  - 114010
PY  - 2018
AB  - The electrical and optical material properties of epitaxial Ge1−xSnx and SiyGe1−x−ySnx are of high interest for novel device applications. However, the limited Sn solubility in Ge makes the epitaxial growth of Ge1−xSnx and SiyGe1−x−ySnx challenging. Most of the literature describing the epitaxial growth is for Ge2H6 and SnCl4 as Ge and Sn precursors, respectively. A more recent publication deals with the epitaxial growth of high-quality Ge1−xSnx with the more conventional GeH4. In this manuscript, we compare the structural and optical material quality of Ge1−xSnx, epitaxially grown on Ge virtual substrates as a function of growth pressure, growth temperature, the choice of the carrier gas (H2 or N2) and the choice of the Ge precursor (GeH4 versus Ge2H6). The best material quality in terms of surface morphology and photoluminescence characteristics is obtained if GeH4 is used as a Ge precursor. For Ge1−xSnx grown with Ge2H6 and at atmospheric pressure, pyramidical defects can be seen and there is a risk for uncontrolled local Sn agglomeration. The pyramidical defects are not observed on Ge1−xSnx layers grown at reduced pressure, but the highest achievable substitutional Sn concentration is lower. No pyramidical defects are found for Ge1−xSnx layers grown with GeH4 and the issue of uncontrolled local Sn agglomeration does not appear.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000448113100002
DO  - DOI:10.1088/1361-6641/aae2f9
UR  - https://juser.fz-juelich.de/record/856521
ER  -