DIFFUSION LIMITING MECHANISM IN SI-DELTA DOPED GAAS GROWN BY METALORGANIC CHEMICAL VAPOR-DEPOSITION

Abstract

Capacitance-voltage measurements at room temperatures have been carried out to investigate the spatial localization of Si in delta-doped GaAs grown by atmospheric pressure metalorganic chemical vapor deposition at several doping densities and temperatures. Even though the growth temperature is as high as 750-degrees-C, the capacitance-voltage profiles show a full-width at half-maximum value of carrier profiles and a Si diffusion coefficient are 44 angstrom and 4 x 10(-17) cm2 s-1, respectively. The value of the diffusion coefficient is an order of magnitude lower than that for molecular beam epitaxy-grown samples at the same temperature. This result will be discussed by using a diffusion limiting mechanism.