Beam geometrical effects on planar selective area epitaxy of heterostructures

Impact of P/In flux ratio and epilayer thickness on faceting for nanoscale selective area growth of InP by molecular beam epitaxy

“…Once again, applying a Wulff geometrical construction allows us to find a relation linking the h/a parameter as defined in the inset of figure 7 and the surface energies for [110]-oriented stripes as proposed by Lee et al [14]: This explains why (111)B facets are prominent for stripes directed along [110]. On the other hand, for the aperture directed along [1][2][3][4][5][6][7][8][9][10], no significant change of the nanostructure shape can be noticed between samples C and F. This is mainly due to the fact that the surface energies (especially the (111)A one) are not very sensitive to variations in the chemical potential.…”

“…Electron beam lithography was used to get patterns of different sizes in the resist deposited on the oxide layer. The pattern consists of 200 nm wide and 4 micron long stripe openings oriented either along the [110] or [1][2][3][4][5][6][7][8][9][10] directions. By means of reactive ion etching, the SiO 2 layer was partially removed inside the patterns so that the remaining thin oxide layer protected the InP surface from damage and contamination during the solvent and hydrogen plasma-cleaning step for resist removal.…”

“…In the 1990s, this approach was used on micrometer scale patterns, as for instance in the work of Heinecke et al which detailed the faceting of InP microcrystals depending on the opening orientation and the value of P/In using metalorganic vapor phase epitaxy (MOVPE) or metalorganic molecular beam epitaxy (MOMBE). They achieved vertical sidewalls on the grown structures for high P/In ratios using small substrate misorientation [1][2][3]. A recent work also reports on the influence on the base size and shape on the formation of InP pyramids by selective area MOVPE, stressing the interplay between the major low-index facets in the final shape [4].…”

“…In this paper, we study the faceting of InP (001) nanocrystals formed in 200 nm wide stripe openings oriented along the [110] and [1][2][3][4][5][6][7][8][9][10] directions. We especially stress the influence of the P/In flux ratio on the final faceting and show that along the [110] direction, the final nanostructure shape can be tailored thanks to the growth conditions.…”

Pretzel Orbits in Simulations of Epitaxial Crystal Growth

“…The aim is to grow successively smooth epitaxial layers of InP and GaInAsP, and to achieve vertical sidewalls. This is only possible under optimized growth conditions for misoriented substrates: The top facet of the substrate must have monoatomic steps [Wachter & Heinecke, 1996;Wachter et al, 1997]. Such a surface can be viewed as a set of large terraces of high symmetry orientation separated by straight parallel steps, as indicated in Fig.…”