Fachbereich 11 - Physik
Institut für Materialphysik
Diffusion and Defects in Elementary and Compound Semiconductors

Source composition effects on dopant diffusion in gallium phosphide

Diffusion in III-V semiconductors such as GaP often proceeds by using diffusion sources containing substantial amounts of Zn. However, such concentrated sources lead to Zn incorporation at high concentration levels which in turn is accompanied by the generation of microstructural defects such as dislocations, precipitates, and voids. To obtain information about the diffusion mechanism and the participating native point defects the formation of diffusion-induced microstructural defects must be avoided. Therefore we investigated diffusion of Zn into GaP for P-rich conditions between 803 °C and 1097 °C from extremely diluted Zn sources. Penetration profiles measured by secondary ion mass spectroscopy and electrochemical capacitance-voltage profiling are in mutual accordance. The profiles are well described within the framework of interstitial-substitutional diffusion yielding not only Zn diffusion coefficients but also transport coefficients for the Ga-related native point defects involved. The latter data are compared with self-diffusion data related to the Ga sublattice in GaP. Here we find discrepancies which require an alternative interpretation. In this context we theoretically explore the possibility that mobile counter-defects, i.e., those belonging to the sublattice opposite to the residence of the diffusing dopant (Zn), play a crucial role in the diffusion process.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft

Beteiligte Wissenschaftler:

Dr. Ch. Jäger (Uni Kiel), Prof. Dr. W. Jäger (Uni Kiel), Dipl. Phys. J. Pöpping, Dr. U. Södervall (Chalmers Univ. of Technology, Göteborg): PD Dr. N.A. Stolwijk (project leader)

Veröffentlichungen:

J. Pöpping, N.A. Stolwijk, G. Bösker, Ch. Jäger, W. Jäger , U. Södervall: Measurements and modeling of zinc diffusion profiles in GaP, Defect and Diffusion Forum 194-199 (2001) 723

N.A. Stolwijk, G. Bösker, J. Pöpping: Hybrid impurity and self-diffusion in GaAs and related compounds, Defect and Diffusion Forum 194-199 (2001) 687

Ch. Jäger, W. Jäger, J. Pöpping, N.A. Stolwijk, U. Södervall: Defect formation during zinc diffusion in GaP, Defect and Diffusion Forum 194-199 (2001) 731

J. Pöpping, N. A. Stolwijk, U. Södervall, Ch. Jäger and W. Jäger, Diffusion of zinc in gallium phosphide under defect-free phosphorus-rich conditions, Physica B 308-310 (2001) 895

N.A. Stolwijk: Possible sublattice interference effects during dopant diffusion in compound semiconductors, Proc. VIII Seminar Diffusion and Thermodynamics of Materials, Brno, Czech Republic, 2002, p. 23