ZN DOPING OF INP GAINASP DEVICE STRUCTURES IN METALORGANIC MOLECULAR-BEAM EPITAXY USING DIETHYLZINC/

Diethylzinc was used as a gaseous p-type dopant source for growth of I nP/GaInAsP layers in metalorganic molecular beam epitaxy. In InP layer s a significant effect of growth temperature on Zn incorporation and o n electrical activation has been found. Additionally, data from a vari ation of the dopant cracker cell temperature suggest that the dopant m olecules should not be fully decomposed for an efficient dopant incorp oration. A comparison of Hall data with data from secondary ion mass s pectrometry (SIMS) reveals that in InP up to 60% of the accepters appe ar to be electrically active under optimized experimental parameters, in GaInAs the activation is above 90%. The SIMS data show that dopant profiles with steep flanks can be obtained in InP/GaInAsP structures. However, a dopant redistribution occurs, which is more pronounced in I nP layers. This effect is correlated with the dopant incorporation beh aviour on substitutional and interstitial sites. The dopant incorporat ion process is discussed in detail, and the implications for growth of InP/GaInAsP device structures are outlined.