INVESTIGATION OF INFLUENCE OF TECHNOLOGICAL IMPURITIES ON THE I–V CHARACTERISTICS OF THE BIPOLAR n–p–n-TRANSISTOR

Contamination of the monocrystal silicon with technological impurities in the devices fabrication process exerts a considerable influence on the electro-physical characteristics of the bipolar n–p–n-transistors. Revelation of the causes of the labile reproducibility of the basic characteristics of the bipolar planar n–p–n-transistors is vital for the purpose of establishing the factors, determining reliability and stability of the operational parameters of the integrated circuits. There were investigated I–V characteristics of the various lots of the bipolar n–p–n-transistors, fabricated under the epitaxialplanar technology as per the similar process charts with the identical used technological materials, however, at different times. It is established that the electro-physical characteristics of the bipolar n–p–n-transistors substantially depend on the contents of the technological impurities in the substrate material. Availability of the high concentration of the generation-recombination centers, related to the metallic impurities, results both in increase of the reverse current of the collector – base junction of the transistors and the significant reduction of the breakdown voltage of the collector junction. The most probable cause of deterioration of the electro-physical parameters of the bipolar n–p–n-transistors is the material contamination with the technological impurities (such, as Fe, Cl, Ca, Cu, Zn and others) during the production process of the devices fabrication. The sources of impurity may be both the components and sub-assemblies of the technological units and the materials and reagents under usage.

I–V characteristics, reverse current of the p–n-junction, breakdown voltage of the p–n-junction, bipolar transistor, technological impurities

1. Odzhaev V.B., Petlitskii A. N., Prosolovich V. S., Turtsevich A. S., Shvedov S. V., Filipenya V. A., Chernyi V. V., Yavid V. Yu., Yankovskii Yu. N., Dubrovskii V. A. The influence of technological impurities on the electrophysical parameters of a MOS transistor. Vestsi Natsyyanal’nai akademii navuk Belarusi. Seryya fizika-technichnych navuk = Proceedings of the National Academy of Sciences of Belarus. Physical-technical series, 2014, no. 4, pp. 14−17 (in Russian).

2. Chelyadinskii A. R., Komarov F. F. Defect-impurity engineering in implanted silicon. Physics-Uspekhi (Advances in Physical Sciences), 2003, vol. 46, pp. 789–820. https://doi.org/10.1070/PU2003v046n08ABEH001371

3. Berneike W., Knoth J., Schwenke H., Weisbrod U., Fresnius Z. Surface analysis for Si-Wafers using total reflection X-ray fluorescence analysis. Fresenius Zeitschrift fürAnalytische Chemie, 1989, vol. 333, iss. 4–5, pp. 524−526. https://doi.org/10.1007/BF00572369

4. Sze S. M. Physics of Semiconductor Devices.New Jersey, John Wiley& Sons, 1969. 812 p.

5. Liefting R., Wijburg R., Custer J. C., Wallinga H., Saris F. W. Improved device performance by multistep or carbon co-implants. IEEE Transactions on Electron Devices, 1994, vol. 41, iss. 1, pp. 50–55. https://doi.org/10.1109/16.259619

6. Sorokin Yu. G. The influence of dislocations on the electrical parameters of p-n junctions. Trudy Vserossiiskogo elektrotekhnicheskogo instituta [Proceedings of the All-Union Electrotechnical Institute]. Moskow, Energiya Publ., 1980, iss. 90, pp. 91–101 (in Russian).

7. Plantinga G. H. Effect dislocations on the transistors parameters fabricated by shallow diffusion. IEEE Transactions on Electron Devices, 1969, vol. 16, iss. 4, pp. 394–400. https://doi.org/10.1109/t-ed.1969.16763