Application of pyrometric interferometry to the in situ monitoring of In0.52Al0.48As, In0.53Ga0.47As, and quaternary alloy growth on InP substrates
1997; Elsevier BV; Volume: 175-176; Linguagem: Inglês
10.1016/s0022-0248(96)00939-6
ISSN1873-5002
AutoresR. M. Sieg, R. N. Sacks, Steven A. Ringel,
Tópico(s)Semiconductor Lasers and Optical Devices
ResumoThe alloy system In0.525(AlxGa1−x)0.475As, which is lattice-matched to InP, covers the technologically important wavelength range 0.8–1.6 μm, including the fiber optic communication wavelengths 1.3 and 1.55 μm. However, growth of these alloys on InP is complicated by the strong dependence of the lattice constant on In content, and would be improved by a convenient in situ method of growth monitoring. We consider the feasibility of extending the method of pyrometric interferometry (PI), whose utility is already established for AlxGa1−xAsGaAs, to In0.52Al0.48As, In0.53Ga0.47As, and general In0.525(AlxGa1−x)0.475AS growth on InP. We find that PI provides useful information about changes in the growth rate and/or composition. The method works best for high Al content films (e.g. In0.52Al0.48As) due to the larger band-gap, and requires about 0.8 μm or thicker film growth for greatest accuracy. PI sensitivity is shown to be greater to changes in the In flux versus the Al flux. We determined the effective refractive index of In0.52Al0.48As to be 3.515 for substrate temperature 500–550°C. The onset of In desorption as the substrate temperature is increased was also easily detected by PI.
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