The main areas of my research activity have been the physics, the vertical electrical characterisation and/or the development
- of metal-nitride-oxide-silicon (MNOS) memory structures and devices [1-3],
- of Schottky junctions and diodes [3-22] including GaAs microwave Schottky tuning varactors [4],
- of metal-porous silicon-silicon structures [23-25],
- of low dimensional (quantum) structures [3,25-28], and
- of amorphous and crystalline SiGe/Si structures and heterodiodes [3,25,29].
     The main goal of my activity has been the understanding of the physical origin of the actual experimental electrical behaviour including anomalies, and the extraction of information about the physical parameters of the structures. So, I have explained different well-known, but not understood earlier, electrical anomalies of Schottky junctions [6,10,11,13,15,17,19,20] (e.g., the so called T0 [10,13,15,19] and inverse T0 [17] anomalies, or the large voltage intercepts of Schottky-Mott plots [6,11,19,20]), and developed several methods of evaluation for extracting physical parameters form the electrical characteristics of MNOS structures [1,2] (evaluation of the memory hysteresis loops [1,2]) and Schottky junctions [5,13,15,18,19] (the extraction of the interface state energy distribution from the current voltage characteristics [5] and their evaluation for the thermionic-field emission [13,15,18]).
     I have also obtained new experimental anomalies, phenomena and relations in Schottky junctions [3,7,12,13,21,22,27] (e.g., anomalous thermionic-field emission [7,13,15], or pinning of the Fermi-level at the metal/AlGaAs and GaAs/AlGaAs interface to the L-band minimum [12]), in metal-porous silicon-silicon structures [23-25] (e.g., the relation between the porosity and the dielectric properties of porous silicon layer [23], or a switching effect [24,25]), and in low dimensional structures [3,25-27] (e.g., current instabilities in GaAs/InAs quantum dot structures [25,27]) and SiGe/Si structures [25,28] (e.g., four limiting mechanisms of the current flow through amorphous SiGe/Si structures [25,28]. One of the outstanding experimental results refers to a world record Schottky barrier height of 0.91 eV obtained on p-type Si [21,22].
     Concerning theoretical results, I have derived general expressions for the Schottky barrier height [8] and for the capacitance-voltage characteristics of Schottky junctions with changing doping level near the interface [6,11]. I have analysed the effect of the metal, interface and semiconductor parameters on the Schottky barrier height [9], the lateral inhomogeneity of barrier height [14[ and its effect on the current-voltage characteristics [17], the temperature dependence of the barrier height [16], and that of the capacitance-voltage characteristics proposing a new plot [20].

[1] Zs.J.Horváth:
Memory hysteresis measurements on silicon oxynitride films
Solid-State Electron. 23, 1053-1054, 1980.

[2] Zs.J.Horváth:
Evaluation of the hysteresis of MNOS memory elements (in Russian)
Proc. 3rd Int. Sci. Coll. T.U. Ilmenau, Oct. 30 - Nov. 3, 1978, Ilmenau, GDR, C2, 81-84.

[3] Zs.J.Horváth:
Electrical breakdown in MIS and MS systems (Review paper)
in: Physics of Semiconductor Devices, Allied Publisher Ltd., New Delhi, India, 2000, (Eds. V. Kumar and S. K. Agarwal), pp. 760-767.

[4] Zs.J.Horváth, I.Gyúró, M.Németh-Sallay, B.Szentpáli, K.Kazi:
GaAs Schottky varactors for linear frequency tuning in X-band
Phys. Stat. Sol. (A) 94, 719-726, 1986.

[5] Zs.J.Horváth:
Evaluation of the interface state energy distribution from Schottky I-V characteristics
J. Appl. Phys. 63, 976-978, 1988.

[6] Zs.J.Horváth:
Comment on "Engineered Schottky barrier diodes for the modification and control of Schottky barrier heights" [J. Appl. Phys. 61, 5159 (1987)]
J. Appl. Phys., 64, 443-444, 1988.

[7] Zs.J.Horváth:
Domination of the thermionic-field emission in the reverse I-V characteristics of n-type GaAs Schottky contacts
J. Appl. Phys., 64, 6780-6784, 1988.

[8] Zs.J.Horváth:
General interfacial layer expression for the equilibrium Schottky barrier height and its application to annealed Au-GaAs contacts
Appl. Phys. Lett., 54, 931-933, 1989.

[9] Zs.J.Horváth:
The effect of the metal, interface, and semiconductor parameters on the electrical behaviour of Schottky junctions
Proc. 19th European Solid State Device Research Conference (ESSDERC'89), Sept.11-14,
1989, Berlin, pp.602-606.

[10] Zs.J.Horváth:
A new approch to temperature dependent ideality factors in Schottky contacts
Mat. Res. Soc. Symp. Proc., 260, 359-366, 1992.

[11] Zs.J.Horváth:
Effect of near-interface concentration change on barrier height in ion-bombarded and heat-treated GaAs Schottky contacts
Mat. Res. Soc. Symp. Proc., 260, 441-446, 1992.

[12] Zs.J.Horváth:
Fermi-level pinning at metal/AlGaAs and GaAs/AlGaAs interfaces
Proc. 16th Annual Semicond. Conf. CAS'93, Oct. 12-17, 1993, Sinaia, Romania, pp. 311-313.

[13] Zs.J.Horváth, A.Bosacchi, S.Franchi, E.Gombia, R.Mosca, A.Motta:
Anomalous thermionic-field emission in epitaxial Al/n-AlGaAs Schottky junctions
Mat. Sci. Eng. B28, 429-432, 1994.

[14] Zs.J.Horváth:
Lateral distribution of Schottky barrier height: a theoretical approach
Vacuum, 46, 963-966, 1995.

[15] Zs.J.Horváth:
Comment on "Analysis of I-V measurements on CrSi2-Si Schottky structures in a wide temperature range"
Solid-State Electron., 39, 176-178, 1996.

[16] Zs.J.Horváth:
Temperature dependence of Schottky barrier height: Role of interface states
Proc. 24th Int. Conf. on Microelectronics, MIEL'96, and 32nd Symp. on Devices and Materials, SD'96, Sept. 25-27, 1996, Nova Gorica, Slovenia, Ed. I.Sorli, S.Amon, M.Kosec, MIDEM Society for Microelectronics, Electronic Components and Materials, Ljubljana, 1996, pp.365-370.

[17] Zs.J.Horváth, Vo Van Tuyen:
Possible explanation of inverse T0 effect in Schottky diodes
Proc. 24th Int. Conf. on Microelectronics, MIEL'96, and 32nd Symp. on Devices and Materials, SD'96, Sept. 25-27, 1996, Nova Gorica, Slovenia, Ed. I.Sorli, S.Amon, M.Kosec, MIDEM Society for Microelectronics, Electronic Components and Materials, Ljubljana, 1996, pp.371-376.

[18] Zs.J.Horváth:
Evaluation of the Schottky current-voltage characteristics for thermionic-field emission
Proc. Int. Conf. on Advanced Semiconductor Devices and Microsystems ASDAM'96, October 20-24, 1996, Smolenice, Slovakia, Eds. T.Lalinsky, F.Dubecky, J.Osvald and S.Hascík, pp. 263-267.

[19] Zs.J.Horváth:
Electrical characterisation of Schottky junctions: Anomalies, parameter extraction and barrier height engineering (Review paper)
in: Physics of Semiconductor Devices, Narosa Publishing House, New Delhi, India, 1998, (Eds. V. Kumar, S. K. Agarwal), pp. 1085-1092.

[20] Zs.J.Horváth, M.Ádám, Cs.Dücsõ, I.Pintér, Vo Van Tuyen, I.Bársony, E.Gombia, R.Mosca, and Zs.Makaró:
Electrical characterisation of Al/n-Si/p-Si Schottky junctions prepared by plasma immersion implantation
Solid-State Electron., 42, 221-228, 1998.

[21] Zs.J.Horváth, M.Ádám, Vo Van Tuyen, Cs.Dücsõ:
Ultrahigh Al Schottky Barrier to p-Si
Proc. 2nd Int. Conf. on Advanced Semiconductor Devices and Microsystems ASDAM'98, Oct. 5-7, 1998, Smolenice Castle, Slovakia, Eds. J.Breza, D.Donoval, V.Drobny and F.Uherek, pp. 83-86.

[22] Zs.J.Horváth, M.Ádám, I.Szabó, M.Serényi, Vo Van Tuyen:
Modification of Al/Si interface and Schottky barrier height with chemical treatment
Appl. Surf. Sci., 190, 441-444, 2002.

[23] M.Ádám, Zs.J.Horváth, I.Bársony, L.Szölgyémy, E.Vázsonyi, Vo Van Tuyen:
Investigation of electrical properties of Au/porous Si/Si structures
Thin Solid Films, 255, 266-268, 1995.

[24] Zs.J.Horváth, E.Vázsonyi, M.Ádám, Vo Van Tuyen, and I.Bársony:
Switching effect in n-type gold/porous silicon/silicon structure
Proc. Int. Conf. on Advanced Semiconductor Devices and Microsystems ASDAM'96,
October 20-24, 1996, Smolenice, Slovakia, Eds. T.Lalinsky, F.Dubecky, J.Osvald and
S.Hascík, pp. 77-79.

[25] Zs.J.Horváth:
Vertical electrical behaviour of GaAs and Si based low dimensional structures (Review paper)
in: Physics of Semiconductor Devices, Allied Publisher Ltd., New Delhi, India, 2002, (Eds. V.
Kumar and P. K. Basu), pp. 265-272.

[26] Zs.J.Horváth, L.Dózsa, Vo Van Tuyen, B.Põdör, ÁNemcsics, P.Frigeri, E.Gombia, R.
Mosca, S.Franchi:
Growth and electrical characteristics of InAs/GaAs quantum well and quantum dot structures
Thin Solid Films, 367, 89-92, 2000.

[27] Zs.J.Horváth, S.Franchi, ABosacchi, P.Frigeri, E.Gombia, R.Mosca, Vo Van Tuyen:
Defect related current instabilities in InAs/GaAs and AlGaAs/GaAs structures?
Solid-State Phenomena, 82-84, 565-567, 2002.

[28] Zs.J.Horváth, P.Frigeri, S.Franchi, Vo Van Tuyen, E.Gombia, R.Mosca, L.Dózsa:
Current instabilities in GaAs/InAs self-aggregated quantum dot structures
Appl. Surf. Sci., 190, 222-225, 2002.

[29] Zs.J.Horváth, K.Jarrendahl, M.Ádám, I.Szabó, Vo Van Tuyen, Zs.Czigány:
Electrical peculiarities in Al/Si/Ge/.../Ge/Si and Al/SiGe/Si structures
Appl. Surf. Sci., 190, 403-407, 2002.

 Last updated: August 14, 2002.