Si/Si_1-xGe_xdots grown by selective epitaxy

Abstract

Using low-pressJre chemical vapour deposition, shgle-layer S:Ge and single-quanlum-well (sow) Si/SiGe dots were deposited by selective epitaxy in Si02 windows using a SiC12H~/GeH2/H~-based chemistry. The un:formih/ of selective deposition was investigated over a range of pads from 300 p m down to 0.14 um. No change of growth rate and Ge fraction in SiGe was Observed for patterns down to 2 pm. Only for 0.18 p m wide dots was a slight increase in Si height measured as compared wsh the unpattemed area. However, the SiGe layer in the sow dois was 3-4 times thicker, which could be dye to islands or to an enhanced growrh of S:Ge in the small openings. Arrays with hundreds of millions of 0.15 Mm single-quantum-well Si/SiGe oots vely uniform in height could oe deDosited.

Facile fabrication of ordered Si1−xGex nanostructures via hybrid process of selective epitaxial growth (SEG) and self-assembled nanotemplates

“…4. The faceting of the Si 1Àx Ge 1Àx observed in the SEM image is commonly observed in Si 1Àx Ge x SEG on the finite areas [37]. On the basis of the results of two preliminary tests, we can conclude that our Si 1Àx Ge x SEG has a great feasibility of selective growth on the Si windows of small lateral size down to 100 nm and high aspect ratio, and fabrication of Si 1Àx Ge x nanostructures using nano-sized Si windows.…”

Size distribution and electroluminescence of self-assembled Ge dots

“…Before epitaxy the wafers were cleaned by RCA cleaning, while the protective 2 nm oxide was removed in situ at 950°C for 10 min under H 2 flow. The epitaxial growth is selective and the growth rate and Ge content of Si 1Ϫx Ge x on Si ͑001͒ do not depend on mesa size down to 0.5-1 m. 11 This implies that independent of mesa area, all diode structures analyzed here have the same layer thickness. The layer thickness, composition, and doping were determined by Rutherford backscattering spectrometry and secondary ion mass spectrometry.…”

Optical properties of Si-Si1−xGex and Si-Ge nanostructures

“…The second method using direct growth is to use a shadow mask and then grow superlattices inside the patterned area [27][28][29]. A typical process is shown in Fig.…”

“…On the other hand, a better understanding of the physics of nanostructures may also introduce new concepts leading to new electronic and optoelectronic devices. The study of Si-SiGe nanostructures is a relative new field, but existing results [16][17][18][19][20][21][22][23][24][25][26][27][28] are already promising for a generation of potentially new optoelectronic devices such as cheap lasers and integrated optoelectronic systems. Recently, several groups have investigated the optical properties of Si SiGe quantum wires [16 21].…”