Philippe Jarry

Monolithic integration of a GaInAs p-i-n photodiode and an optical waveguide: modeling and realization using chloride vapor phase epitaxy

A theoretical and experimental study is discussed of a p-i-n GaInAs photodiode integrated with inverted-rib InP or GaInAsP waveguides grown on InP substrate. The coupling efficiency between the waveguide and the photodiode is calculated using the beam-propagation method while the initial condition, i.e. the waveguide eigenmode, is calculated by the finite-difference method. The photodiode absorption is calculated as a function of key design parameters, which are the waveguide dimensions, the wavelength and, in the case of heterostructure waveguide, the composition of the quaternary layer. Two classes of device application are foreseen: monitor photodiode and end line receiver. >

Total in situ etching and regrowth in an MBE system: application to buried heterostructure lasers

A new chlorine-based chemical beam etching technique (CBET) has been combined with molecular beam epitaxy (MBE) technology to prepare InP-InGaAsP buried heterostructures in a total in situ etching and regrowth process for the first time. This novel processing technology, combining two techniques in the same MBE growth chamber, is very attractive for the realization of high-performance discrete or integrated optoelectronic devices. The different aspects of the etching process optimization are reviewed in the case of InP-InGaAsP heterostructures, and a first application to buried heterostructure laser fabrication is presented. The results obtained for buried ridge stripe (BRS) lasers are very promising and compare favorably to the state-of-the-art lasers. This first device application passes a milestone in the development of this new technology and demonstrates its potential for further applications to the fabrication of optoelectronic devices.

Chemical beam etching of InP in GSMBE

Etching of InP using a beam of PC13 is demonstrated in a standard gas source molecular beam epitaxy machine. The principle of an atomic layer accurate end-point detection technique usingin-situ reflection high energy electron diffrac-tion is described and used to study the kinetics of PCl3 etching. The etch rate is found proportional to the PCI3 fluence and weakly dependent on the substrate temperature. The morphology of etched surfaces and the etch rate uniformity is compatible with the regrowth of high quality InGaAsP active structures and with the realization of etch and regrowth sequences controlled at the nm scale. Etch profiles at mask edges are defined by nearly perfect crystallographic facets with a very limited mask undercut (≈100 nm) due to the beam nature of the etching technique.

Single run etching and regrowth of InP/GaInAsP by GSMBE

We report for the first time the successful etching of InP/GaInAsP heterostructures by the chemical beam etching technique using PCl/sub 3/, and on the combination of this etching technique with regrowth using standard GSMBE conditions. The kinetics of etching have been studied over a large temperature range. The difference in etch rates between InP and GaInAsP is explained by a difference in the group III chloride stoichiometry (InCl, GaCl/sub 3/). This difference leads probably to a modification of the surface composition during etching, the surface becoming richer in Ga. The dopants (Si, Be) are found to accumulate at the etch/regrown interface. The silicon atoms are not removed and create a /spl delta/-doped layer at the regrowth interface, The surface morphology of etched samples have been improved by etching at low temperature, in agreement with the RHEED observations showing a smooth 2D layer by layer etching mode in this case. In particular, the decoration of dislocations observed after etching at high temperature is not found on low temperature etched samples. This low temperature etching procedure is well adapted to the regrowth of high quality InP/GaInAsP structures.

Low threshold current BH lasers fabricated by UHV chemical beam etching and GSMBE regrowth

A new chlorine-based chemical beam etching technique (CBET) compatible with MBE or CBE technology has been introduced recently. The process sequence combining these two techniques in the same MBE growth chamber is very attractive for the realisation of high performance discrete or integrated optoelectronic devices. In this paper, we present for the first time results on devices fabricated using this new processing technique. Fabry-Perot type 1.3 and 1.48 /spl mu/m Buried Heterostructure lasers with low threshold current values have been obtained. Well defined mesa profiles and excellent regrowth morphologies have been obtained. The effect of interface contamination has been pointed out, in particular for the case of silicon for which a direct effect on laser results has been shown.