STUDY ON THERMAL-STABILITY OF CARBON-DOPED GAAS USING NOVEL METALORGANIC MOLECULAR-BEAM EPITAXIAL STRUCTURES

Two novel carbon-doped structures grown by metalorganic molecular beam epitaxy were used to study thermal stability over the temperature ran ge from 650 to 800-degrees-C. Each structure consists of several GaAs layers with different carbon concentrations to characterize thermal st ability of GaAs layers with various carbon concentrations simultaneous ly. The structure shows no significant carbon diffusion even after an 800-degrees-C-240 min anneal. However, the hole concentration of each carbon-doped GaAs layer in both structures has decreased, and a decrea se of the hole concentration is more significant for a higher carbon c oncentration. With increasing the annealing time or temperature, the h ole concentrations of all carbon-doped GaAs layers approach to the sam e value, low 10(19) cm-3.