MOCVD OF ALGAAS/GAAS WITH NOVEL GROUP-III COMPOUNDS

The MOCVD of AlGaAs and GaAs from coordinatively saturated group III source materials i.e. 1-3-dimethyl-aminopropyl-l-galla-cyclohexane ((C5H10)Ga(C2N(CH3 2) and the corresponding Al compound) was investigated. It was demonstrated that these precursors, which are inherently free of alkoxy contamination, are suitable for epitaxial growth of GaAs layers and structures of GaAs/AlGaAs. For comparison, data achieved with TEA (Al(C2H5)3) or TiBA (Ali(C4H9)3) and TEG (Ga(C2H5)3) are presented. A basic finding of this study is that due to the low thermal stability of TEA, TiBA and TEG the layers grown from these compounds suffer from insufficient homogeneity of layer thickness and composition. In contrast, the coordinatively saturated compounds show a reactivity suitable for large area growth. Additionally, intrinsic impurity (N, C) uptake appears to be low and electrical as well as PL data show the satisfactory quality of GaAs and AlGaAs layers grown from this new type of precursors. Specifically, a reduction of oxygen incorporation compared to growth from the standard trialkyls is indicated by PL measurements on layers grown at different temperatures. © 1990 The Mineral,Metal & Materials Society,Inc.