Cite this article as:

Yafarov R. ., Nefedov D. V. Influence of Plasma-Chemical Modification of the Surface on Transverse Electron Transport and VAC of Silicon MIS Structures. Izvestiya of Saratov University. New series. Series Physics, 2019, vol. 19, iss. 1, pp. 76-82. DOI: https://doi.org/10.18500/1817-3020-2019-19-1-76-82


UDC: 
539.234
Language: 
Russian

Influence of Plasma-Chemical Modification of the Surface on Transverse Electron Transport and VAC of Silicon MIS Structures

Abstract

Background and Objectives: The laws governing the modification of the current-voltage characteristics of the metal-insulatorsemiconductor structures due to the formation of embedded surface potentials are investigated. Surface potentials are formed when an atomically clean surface of silicon crystals is produced using microwave plasma micromachining. The aim of the work is to study the effect of plasma micromachining in various chemically active gaseous media on the properties of silicon MIS structures. Materials and Methods: In the experiments, silicon (100) crystals of various types of conductivity with a specific resistance of 0.01 ... 0.02 Ohm · cm were used. After low-energy microwave plasmachemical etching in freon-14 or argon medium, the sequentially sealing tunnel-thin (10–20 nm) silicon carbide layer and silicon dioxide layer of 0.5 microns thick were deposited on the gate region of the structure in the same technological cycle. A layer of amorphous silicon with a thickness of 20 nm was deposited on the drain and source. Then metal contacts were applied to all areas. The measurement data were recorded using the ADC. The supply voltage was carried out using a two-channel block ATTEN APS3005S-3D. Results: With a positive polarity at the gate of the MIS structure, minority charge carriers in the p-type semiconductor tunnel into trap centers at the crystal boundary, partially neutralizing the applied external potential. Since the built-in spatial potential is larger during etching in the argon plasma than that with plasma-chemical etching in the freon-14 medium, the weakening of the external field is greater in the case of argon. In the case of plasma processing of n-type silicon crystals in the medium of freon-14, the negative total gate field is less than after the treatment in the argon medium. Conclusion: The influence of the built-in surface potential on the slope of the VAC of MIS devices based on silicon crystals of various types of conductivity, as well as their asymmetry upon changing the polarity on the gate can be used, for example, when creating specialized information recording and reading devices, TVS diodes with asymmetric direct and reverse branches VAC, other devices and devices of the nanosystem technology.

References

1. Bhattacharyya R., Mukherjee C., Sushil Kumar, Dixit P. N. Cold plasma processing for some novel material development. AIP Conference Proceedings, 2015, vol. 1670, pp. 020002. DOI: https://doi.org/10.1063/1.4926681

2. Geissbuhler J., De Wolf S., Demaurex B., Seif J. P., Alexander D. T., Barraud L., Ballif C. Amorphous/crystalline silicon interface defects induced by hydrogen plasma treatments. Appl. Phys. Lett., 2013, vol. 102, pp. 231604. DOI: https://doi.org/10.1063/1.4811253

3. Fujino Y., Kita K. Estimation of near-interface oxide trap density at SiO2/SiC metal-oxide-semiconductor interfaces by transient capacitance measurements at various temperatures. J. Appl. Phys., 2016, vol. 120, pp. 085710. DOI: https://doi.org/10.1063/1.4961871

4. Bonch-Bruevich V. L., Kalashnikov S. G. Fizika poluprovodnikov [Semiconductor physics]. Moscow, Nauka Publ., 1977. 672 p. (in Russian).

5. Oura K., Lifshic V. G., Saranin A. A. Vvedenie v fi ziku poverhnosti [Introduction to surface physics]. Moscow, Nauka Publ., 2006. 490 p. (in Russian).

6. Yafarov R. K. Nonequilibrium the Microwave Plasma of Low Pressure in Scientifi c Researches and Development Micro and Nanoelectronics. Izv. Saratov Univ. (N. S.), Ser. Physics, 2015, vol. 15, iss. 2, pp. 16‒31 (in Russian).

7. Yafarov R. K. Fizika SVCh vakuumno-plazmennyh nanotekhnologij [Physics of microwave vacuum plasma nanotechnology]. Moscow, Fizmatlit Publ., 2009. 216 p. (in Russian).

8. Mews M., Mader C., Traut S., Sontheimer T., Wunnicke O., Korte L., Rech B. Solution-processed amorphous silicon surface passivation layers. Appl. Phys. Lett., 2014, vol. 105, pp. 122113. DOI: https://doi.org/10.1063/1.4896687

9. Kudo T., Ito T., Nakajimaa A. Characteristics of metal– oxide–semiconductor fi eld-effect transistors with a functional gate using trap charging for ultralow power operation. J. Vac. Sci. Technol. B, 2013, vol. 31, pp. 012206. DOI: https://doi.org/10.1116/1.4773576

10. Moore J. E., Dongaonkar S., Chavali R. V. K., Alam M. A., Lundstrom M. S. Correlation of Built-In Potential and I–V crossover in Thin-Film Solar Cells. IEEE Journal of Photovoltaics, 2014, vol. 4, iss. 4, pp. 1138–1148. DOI: https://doi.org/10.1109/JPHOTOV.2014.2316364

11. Mueller F., Konstantaras G., van der Wiel W. G., Zwanenburga F. A. Single-charge transport in ambipolar silicon nanoscale fi eld-effect transistors Appl. Phys. Lett., 2015, vol. 106, pp. 172101. DOI: https://doi.org/10.1063/1.4919110

Short text (in English): 
Full text (in Russian):