A novel structure in Ge/Si epilayers grown at low temperature

Anomalous x-ray scattering study of the growth of inverted quantum hut structures in a Si-Ge superlattice emitting strong photoluminescence

“…But on the contrary, it was observed recently by electron microscopy studies that surprisingly large length-scale interdiffusion of Ge occurs in the underlying Si layers at low growth temperatures (∼450 • C), provided the deposited Ge layer thickness is kept between 22 and 38Å [12][13][14][15]. This enigmatic interdiffusion of Ge in the underlying Si lattice at lower growth temperature ( 500 • C) leads to the formation of quantum hut structures within the Si sublayer below the Ge wet layer with the apex pointing down towards the Si substrate.…”

Grazing incidence X-ray scattering from Ge/Si superlattices grown at low temperature

“…In the low growth temperature modified SK technique, ''groove islands'' or ''inverted huts'' of crystallized SiGe have been observed to form beneath the Ge wetting layer and grow into the Si layer in Ge/Si superlattices [10,11]. The formation of the ''inverted huts'' depends on the Ge thickness in the Ge/Si superlattices as well the growth temperatures.…”

“…The large interface width associated with the Si layers in the samples with thicker Ge layers appears to correspond to the electron density grading resulting from the regular ''inverted huts'' profile beneath the Ge-layers [10]. To fit the interface width to a reasonable value, we assume that there exists a sublayer of Ge-Si mixing at the Ge/Si interface.…”

“…However, Cheng et al [10] have reported a modified SK growth technique, which produced high quality Si-Ge alloy nanostructures at much lower growth temperatures (260-450°C). In contrast to the pure Ge clusters appearing on top of the Ge layer in the SK mode, 3-dimensional arrays of inverted Si-Ge islands are grown into the Si layer by this modified technique.…”

Characterization of the local structure of Ge quantum dots by X-ray absorption

“…The properties of Si/Ge/Si structures, Si/Ge superlattices and SiGe/Si-heterostrustures were studied most actively by the methods of electron and atomic-force microscopy (AFM) [4][5][6][7][8][9][10][11][12], X-ray absorption fine structure (XAFS) [13,14], photoluminescence (PL) [5][6][7][8][15][16][17][18][19][20][21][22], RHEED [20], scanning tunneling microscopy (STM) [23], Auger electron spectroscopy (AES) [24] and Raman scattering [5,20,[25][26][27][28][29]. Nevertheless, there are some questions without answers concerning understanding and controlling the morphology of interface particularly in the buried layers.…”