Influence of Precursor Concentration on the Determination of AlInGaAs Solid-State Compositions Grown by Metalorganic Vapor Phase Epitaxy

The epitaxial growth of AlInGaAs alloys on InP allows the manufacture of semiconductor lasers that emit in the wavelength range between 1200 and 1600 nm in which the optical telecommunication bands lie. These alloys are particularly well suited for manufacturing lasers intended for operation at higher temperatures. A model relating the metalorganic vapor phase epitaxy (MOVPE) growth settings for AlInGaAs on InP to the resultant bandgap energy is presented, for strained and unstrained compositions, based on a new dataset measured on epitaxial layers grown in a novel planetary epitaxy reactor, using the 12x4 inch configuration. Elemental analysis (ICP-OES) was employed to relate the growth settings to the solid-state composition of the resulting alloy, to ensure our model takes meaningful input. It was found that the MOVPE growth settings and the solid-state composition as determined by ICP-OES only showed a one-to-one correspondence once the right set of vapor pressure coefficients for the precursors was chosen.