Selective metalorganic vapor phase epitaxial growth of InGaAsP / InP layers with bandgap energy control in InGaAs / InGaAsP multiple-quantum well structures

A model for isotropic crystal growth from vapor on a patterned substrate

“…Figures 8(b), 9(b)) was found experimentally in [7] for the surface diffusion dominated growth. Also, Figure 9(a) shows that the film thickness at the center of the substrate region monotonically increases with the mask width ℓ due to the increase of the lateral source supply .…”

“…The profiles of the crystal surface we obtained show close resemblance to experimental profile in Figure 5(b) of [3] and to experimental profiles in Figures 4 and 5 of [7]. To make such comparison, our computed profiles should be truncated, at some given time, with imaginary vertical line passing to the left of the "bump" maxima.…”

“…We don't study surface diffusion along the vertical part of the step and assume that atoms diffused over the corner are incorporated in the growing crystal instantly. This approximation is good if the mask thickness is much less than the mask region width, that is if h m ≪ ℓ (in ELOG the ratio h m /ℓ is usually < 0.1 [3,5,7], [11]- [15], [17]. In SAG this ratio is so small that the mask can be considered to be of vanishing thickness).…”

“…It is generally concluded that diffusion lengths on the mask and on the surface of the epitaxial material such as GaAs, Si or GaN are very short (of the order of 1 µm). Under these conditions, the dominant lateral mass transport mechanism from the mask regions, for distances greater than a few (say 10) microns, is usually attributed to vapor-phase diffusion [5,6,7], [9]- [11]. However, surface diffusion usually dominates [6,7,11,17,18] for the growth in narrow windows bounded by narrow mask regions (< 10 microns) and it is this case (ELOG) that we are interested in studying.…”

Silicon-Germanium multi-quantum wells for extended functionality and lower cost integration

“…Nanostructural characterization (TEM, XPS, photoluminescence) indicates low-dislocation density, high quality films. Solar cells made of these layers have low leakage current.Current state-of-the-art near infrared photodetectors are based on InGaAs [1], due to WKH PDWHULDO ¶V (i) ease of integration with InGaAsP lasers for optical communication systems [2], (ii) high degree of tunability of the direct band gap energy and absorption [3] and (iii) low dark current using lattice matched wide bandgap materials [4]. The mature Silicon CMOS technology provides a lower cost platform while optoelectronics offers high performance and increased functionality.…”