Profiles ofZn in n-type InP(100) wafers after ampoule diffusion were measured by secondaryion mass spectrometry, Auger electron spectrometry, differential Hall-effect measurements, capacitance measurements, and scanning electron microscopy. The results can be explained by an interstitial-substitutional mechanism, in which Zn diffuses as a singly ionized interstitial and is incorporated in the In sublattice as an electrically active substitutional acceptor or as an electrically inactive complex. At Zn concentrations lower than the background donor concentration the profile is cut off', as interstitial diffusion breaks down. The acceptor solubility increases with background donor concentration. Activation energies for diffusion and solubility were found to be 1.40 and 1.0 eV, respectively.

Boron and arsenic concentration profiles, diffused from polycrystalline silicon (polysilicon) into the underlying-single crystalline silicon (mono) substrate, were analyzed by Rutherford backscattering spectrometry and secondary ion mass spectrometry for various levels of oxygen concentration at the poly/mono interface. In contrast with previous reports it was found that chemically grown interfacial oxide layers of about 1.4-nm thickness provide more effective diffusion sources than oxygen-free interfaces. This surprising phenomenon is caused by the strong correlation between the crystalline structure of the polysilicon layer and the diffusion rates of dopant species in that layer. It is shown that the small amount of oxide at the poly/mono interface prevents the epitaxial realignment of the polysilicon, thereby maintaining high diffusion rates in the polysilicon, without offering a significant barrier to the diffusion of boron and arsenic across the interface.

Ampoule diffusion of Zn in undoped liquid phase epitaxial InGaAsP layers between 425 and 525 °C shows the Zn solubility, as measured with secondary ion mass spectrometry, to be much larger than in InP and to be slightly less than in GaAs. The acceptor concentration, as determined by capacitance-voltage measurements, is 60%–90% of the Zn concentration. Incorporation and diffusion of Zn can be described with the interstitial-substitutional model. The difference between the acceptor and Zn concentrations can be explained by compensating Zn interstitial donors or by neutral Zn-vacancy complexes. The diffusion depth is slightly smaller than in InP and much larger than in GaAs. In n-type InGaAsP, profiles are found with a cut-off similar to the behavior in InP. The solubility is higher than in undoped InGaAsP.