Aynı koşullar altında üretilen Au/p-TlInS2/n-InP pseudo Schottky eklemlerin karakteristik parametrelerinin istatistiksel incelenmesi

Öz

Au/p-TlInS2/n-InP Psödo-Schottky (PS) eklemleri, ön yüzüne omik kontak yapılmış n-InP altlığın arka yüzeyine altın (Au) doğrultucu kontak imalatından önce ince p-TlInS2 inversiyon tabakası büyütülerek üretildi. Metal-yarı iletken arayüzeyinin kararlılığı için ardışık tavlama işlemi uygulandı. Azot gazı atmosferinde 200 oC'de 5 dakika süreli ardışık ikinci tavlama işleminden sonra engel yüksekliğinde (EY) yaklaşık 0,260 eV’luk bir artış gözlemlendi. Aynı şartlarda üretilmiş (18 nokta) Au/p-TlInS2/n-InP PS eklemlerinin EY, idealite faktörü (n) ve seri direnc (Rs) parametreleri Termiyonik Emisyon (TE) teorisi kullanılarak oda sıcaklığı ve karanlıkta ölçülmüş akım-voltaj (I-V) ve kapasite-voltaj (C-V) karakteristiklerinden hesaplandı. I-V ve C-V karakteristiklerinden hesaplanan EY sırasıyla (0.620-0.844) eV ve (0.669-0.973) eV, idealite faktörü n (1.023-1.706) ve Rs seri direnç değerleri ise (28.3-131) Ω aralığında değişim sergilemektedir. Aynı koşullar altında hazırlanmalarına rağmen PS eklemlerin karakteristik parametreleri kendileri arasında farklılık gösterdiğinden, eklem parametreleri üzerinde Tung modeli kullanılarak istatistiksel bir çalışma yapıldı. Gauss fonksiyonu ile fit edilen EY, n ve Rs verilerinin ortalama değerleri sırasıyla ϕ ̄_(I-V)=(0.7⁡5 5 〖±0.0〗⁡5 9) eV, ϕ ̄_(C-V)=(0.8⁡0 3 〖±0.〗⁡0 78) eV, n =(〖1.〗⁡3 84 〖±0.〗⁡1 52) andR_s=(88.4 ±⁡2 8.0)Ω olarak elde edildi. Au/p-TlInS2/n-InP PS eklemi için yanal homojen EY (ϕ_(hom.)), n_(imf.)=1.006 ve Δϕ_(imf.)=18.0 meV değerleri kullanılarak ϕ_(eff.) "- n" çiziminden ϕ_(hom.)=0.800 eV olarak elde edilmiştir. C-V ölçümlerinden elde edilen ortalama EY değeri ϕ_(hom.) ile oldukça uyum içindedir. Parametrelerdeki bu uyum, Au/p-TlInS2/n-InP PS ekleminde gözlenen EY inhomojenliğinin Tung tarafından ileri sürülen EY'nin uzaysal dağılımı hipotezi dikkate alınarak açıklanabileceğini gösterir.

Anahtar Kelimeler

• n-InP
• p-TlInS2
• pseudo Schottky eklem
• I-V and C-V ölçümü
• engel inhomojenliği
• Tung modeli

Statistical investigation of characteristic parameters for Au/p-TlInS2/n-InP pseudo Schottky junctions produced under the same conditions

Abstract

Pseudo-Schottky junctions (PSJs) on moderately doped (MD) n-InP were fabricated by introducing a thin p-TlInS2 counter layer before the assembly of gold rectifying contact. Successively annealing treatment was applied to create a stable inversion layer at the metal-semiconductor (MS) interface. PSJs were made with a significant barrier height (BH) enhancement, typically by the value of 0.260 eV for gold Schottky gate, after the second annealing process at 200 oC in a nitrogen atmosphere for 5 minutes. Junction parameters such as BH, ideality factor (n) and serial resistance (Rs) of identically fabricated (18 dots) Au/p-TlInS2/n-InP PSJs have been computed by thermionic emission (TE) theory from current-voltage (I-V) and capacitance-voltage (C-V) characteristics, at room temperature and in the dark. BHs derived from I-V and C-V characteristics varied from 0.620 to 0.844 eV and 0.669 to 0.973 eV, respectively. In addition, the values of n varied from 1.023 to 1.706 and the serial resistances Rs varied from 28.3 to 131 Ω. Since all parameters of PSJs differ from one junction to another, even if they are prepared under the same conditions, a statistical study was made on the junction parameters using Tung’s model. The mean values of the experimental BH, the ideality factor, and the series resistance data, which were fitted by the Gaussian function, were found to be ϕ ̄_(I-V)=(0.7⁡5 5 〖±0.0〗⁡5 9) eV, ϕ ̄_(C-V)=(0.8⁡0 3 〖±0.〗⁡0 78) eV, n =(〖1.〗⁡3 84 〖±0.〗⁡1 52) and〖 R〗_s=(88.4 ±⁡2 8.0)Ω, respectively. The lateral homogeneous BH (ϕ_(hom.)) value of 0.800 eV for the Au/p-TlInS2/n-InP junctions has been obtained from the ϕ_(eff.) "- n" plot by using n_(imf.)=1.00⁡6 and Δϕ_(imf.)=18.0 meV It has been seen that the mean BH obtained from the C-V measurements correlates well with the value of ϕ_(hom.). The good agreement in these parameters indicates that the BH inhomogeneity observed in the Au/p-TlInS2/n-InP PJ can be described by considering the spatial distribution hypothesis of BH put forward by Tung.

Keywords

• n-InP
• p-TlInS2
• pseudo-Schottky junction
• I-V and C-V measurement
• barrier inhomogeneities
• Tung’s model

Kaynakça

1. Abay, B. (2015). Barrier characteristics of biopolymer-based organic/inorganic Au/CTS/n-InP hybrid junctions. The Philosophical Magazine a Journal of Theoretical Experimental and Applied Physics, 95(31), 3413–3428. https://doi.org/10.1080/14786435.2015.1076583
2. Abay, B., Ankaya, G., Der, H. S. G., Efeoglu, H., & U, Y. K. Y. (2002). Barrier characteristics of Cd/p-GaTe Schottky diodes based onI V Tmeasurements. Semiconductor Science and Technology, 18(2), 75–81. https://doi.org/10.1088/0268-1242/18/2/302 Abay, B., Efeoglu, H., Yogurtçu, Y. K., & Alieva, M. (2001b). Low-temperature visible photoluminescence spectra of Tl2GaInSe4layered crystals. Semiconductor Science and Technology, 16(9), 745–749. https://doi.org/10.1088/0268-1242/16/9/302
3. Abay, B., Güder, H., Efeoğlu, H., & Yoğurtçu, Y. (2001a). Temperature dependence of the optical energy gap and Urbach–Martienssen’s tail in the absorption spectra of the layered semiconductor Tl2GaInSe4. Journal of Physics and Chemistry of Solids, 62(4), 747–752. https://doi.org/10.1016/s0022-3697(00)00236-5 Abay, B., Güder, H. S., Efeoglu, H., & Yogurtçu, Y. K. (2000b). Excitonic absorption and Urbach-Martienssen tails in Gd-doped and undoped p-type GaSe. Semiconductor Science and Technology, 15(6), 535–541. https://doi.org/10.1088/0268-1242/15/6/308
4. Abay, B., Güder, H., Efeoğlu, H., & Yoğurtçu, Y. (2001c). Urbach-Martienssen Tails in the Absorption Spectra of Layered Ternary Semiconductor TlGaS2. Physica Status Solidi. B, Basic Research, 227(2), 469–476. https://doi.org/10.1002/1521-3951(200110)227:2 Abay, B., Onganer, Y., Saǧlam, M., Efeoǧlu, H., Türüt, A., & Yoǧurtçu, Y. (2000a). Current–voltage and capacitance–voltage characteristics of metallic polymer/InSe(:Er) Schottky contacts. Microelectronic Engineering, 51–52, 689–693. https://doi.org/10.1016/s0167-9317(99)00532-8
5. Abay, A. (1994), Growth and investigation for some optical and electrical properties of TlInSe2 and TlGaSe2 ternary layered semiconductor crystals as a function of temperature, PhD Thesis (in Turkish), Atatürk University Graduate School of Natural & Applied Science Erzurum, Turkey (unpublished).
6. Brillson, L. J., Brucker, C. F., Katnani, A. D., Stoffel, N. G., Daniels, R., & Margaritondo, G. (1982). Fermi-level pinning and chemical structure of InP–metal interfaces. Journal of Vacuum Science & Technology/Journal of Vacuum Science and Technology, 21(2), 564–569. https://doi.org/10.1116/1.571764 Campbell, I. H., Rubin, S., Zawodzinski, T. A., Kress, J. D., Martin, R. L., Smith, D. L., Barashkov, N. N., & Ferraris, J. P. (1996). Controlling Schottky energy barriers in organic electronic devices using self-assembled monolayers. Physical Review. B, Condensed Matter, 54(20), R14321–R14324. https://doi.org/10.1103/physrevb.54.r14321
7. Chand, S., & Bala, S. (2007). Simulation studies of current transport in metal–insulator–semiconductor Schottky barrier diodes. Physica. B, Condensed Matter, 390(1–2), 179–184. https://doi.org/10.1016/j.physb.2006.08.011
8. Chattopadhyay, P., & Daw, A. (1986). On the current transport mechanism in a metal—insulator—semiconductor (MIS) diode. Solid-state Electronics, 29(5), 555–560. https://doi.org/10.1016/0038-1101(86)90078-x

9. Chou, L. J., Hsieh, K. C., Wohlert, D. E., Cheng, K. Y., & Finnegan, N. (1998). Formation of amorphous aluminum oxide and gallium oxide on InP substrates by water vapor oxidation. Journal of Applied Physics, 84(12), 6932–6934. https://doi.org/10.1063/1.368993
10. Clausen, T., & Leistiko, O. (1993). High effective Schottky barriers on n-type InP using Zn-based metallizations and rapid thermal annealing. Semiconductor Science and Technology, 8(9), 1731–1740. https://doi.org/10.1088/0268-1242/8/9/011
11. Çakar, M., Türüt, A., & Onganer, Y. (2002). The Conductance- and Capacitance-Frequency Characteristics of the Rectifying Junctions Formed by Sublimation of Organic Pyronine-B on p-Type Silicon. Journal of Solid State Chemistry, 168(1), 169–174. https://doi.org/10.1006/jssc.2002.9706
12. Çankaya, G., & Abay, B. (2005). Current- and capacitance-voltage characteristics of Cd/p-GaTe Schottky barrier diodes under hydrostatic pressure. Semiconductor Science and Technology, 21(2), 124–130. https://doi.org/10.1088/0268-1242/21/2/004
13. Donald, A.N. (1982). Semiconductor Physics and Devices, (Boston, Irwin).
14. Gasanly, N. M. (2010). Coexistence of Indirect and Direct Optical Transitions, Refractive, Index and Oscillator Parameters in TlGaS2 , TlGaSe2 , and TlInS2 Layered Single Crystals. Journal of the Korean Physical Society, 57(1), 164–168. https://doi.org/10.3938/jkps.57.164
15. Güder, H., Abay, B., Efeoğlu, H., & Yoğurtçu, Y. (2001). Photoluminescence characterization of GaTe single crystals. Journal of Luminescence, 93(3), 243–248. https://doi.org/10.1016/s0022-2313(01)00192-2
16. Gupta, R. K., & Singh, R. A. (2005). Junction properties of Schottky diode based on composite organic semiconductors: Polyaniline-polystyrene system. Journal of Polymer Research, 11(4), 269–273. https://doi.org/10.1007/s10965-005-2412-2
17. Hökelek, E., & Robinson, G. (1981). A comparison of Pd Schottky contacts on InP, GaAs and Si. Solid-state Electronics, 24(2), 99–103. https://doi.org/10.1016/0038-1101(81)90001-0
18. Hudait, M., & Krupanidhi, S. (2001b). Doping dependence of the barrier height and ideality factor of Au/n-GaAs Schottky diodes at low temperatures. Physica. B, Condensed Matter, 307(1-4), 125–137. https://doi.org/10.1016/s0921- 4526(01)00631-7
19. Hudait, M., Venkateswarlu, P., & Krupanidhi, S. (2001a). Electrical transport characteristics of Au/n-GaAs Schottky diodes on n-Ge at low temperatures. Solid-state Electronics, 45(1), 133–141. https://doi.org/10.1016/s0038-1101(00)00230-6 Im, H. J., Ding, Y., Pelz, J. P., & Choyke, W. J. (2001). Nanometer-scale test of the Tung model of Schottky-barrier height inhomogeneity. Physical Review. B, Condensed Matter, 64(7). https://doi.org/10.1103/physrevb.64.075310 Ismail, A., Brahim, A. B., Dumas, M., & Lassabatere, L. (1987). The interaction of Ag and Al overlayers with InP (110): Surface and diode studies of the effect of Sb interlayers. Journal of Vacuum Science & Technology. B, Microelectronics Processing and Phenomena, 5(3), 621–623. https://doi.org/10.1116/1.583793
20. Kampen, T., & Mönch, W. (1995). Lead contacts on Si(111):H-1 × 1 surfaces. Surface Science, 331–333, 490–495. https://doi.org/10.1016/0039-6028(95)00079-8
21. Kaya, M., Çetin, H., Boyarbay, B., Gök, A., & Ayyildiz, E. (2007). Temperature dependence of the current–voltage characteristics of Sn/PANI/p-Si/Al heterojunctions. Journal of Physics. Condensed Matter, 19(40), 406205. https://doi.org/10.1088/0953-8984/19/40/406205
22. Lang, O., Schlaf, R., Tomm, Y., Pettenkofer, C., & Jaegermann, W. (1994). Single crystalline GaSe/WSe2 heterointerfaces grown by van der Waals epitaxy. I. Growth conditions. Journal of Applied Physics, 75(12), 7805–7813. https://doi.org/10.1063/1.356562
23. Lee, P. A. (1976). Optical and Electrical Properties.
24. Leroy, W., Opsomer, K., Forment, S., & Van Meirhaeghe, R. (2005). The barrier height inhomogeneity in identically prepared Au/n-GaAs Schottky barrier diodes. Solid-state Electronics, 49(6), 878–883. https://doi.org/10.1016/j.sse.2005.03.005
25. Lieth, R. M. A. (2014). Preparation and Crystal Growth of Materials with Layered Structures.
26. Maeda, F., Watanabe, Y., & Oshima, M. (1993). Surface chemical bonding of (NH4)2Sx-treated InP(001). Applied Physics Letters, 62(3), 297–299. https://doi.org/10.1063/1.108996
27. McCafferty, P., Sellai, A., Dawson, P., & Elabd, H. (1996). Barrier characteristics of Schottky diodes as determined from I-V-T measurements. Solid-state Electronics, 39(4), 583–592. https://doi.org/10.1016/0038-1101(95)00162-x Mönch, W. (1999). Barrier heights of real Schottky contacts explained by metal-induced gap states and lateral inhomogeneities. Journal of Vacuum Science & Technology. B, Microelectronics and Nanometer Structures, 17(4), 1867–1876. https://doi.org/10.1116/1.590839
28. Mönch, W. (2001). Semiconductor Surfaces and Interfaces. In Springer series in surface sciences. https://doi.org/10.1007/978-3-662-04459-9
29. Osvald, J., & Horváth, Z. (2004). Theoretical study of the temperature dependence of electrical characteristics of Schottky diodes with an inverse near-surface layer. Applied Surface Science, 234(1–4), 349–354. https://doi.org/10.1016/j.apsusc.2004.05.046
30. Rhoderick, E. H., & Williams, R. H. (1988). Metal-semiconductor Contacts. Oxford University Press, USA.
31. Schmitsdorf, R. F., Kampen, T. U., & Mönch, W. (1997). Explanation of the linear correlation between barrier heights and ideality factors of real metal-semiconductor contacts by laterally nonuniform Schottky barriers. Journal of Vacuum Science & Technology. B, Microelectronics and Nanometer Structures, 15(4), 1221–1226. https://doi.org/10.1116/1.589442
32. Schvartzman, M., Sidorov, V., Ritter, D., & Paz, Y. (2001). Surface passivation of (100) InP by organic thiols and polyimide as characterized by steady-state photoluminescence. Semiconductor Science and Technology, 16(10), L68–L71. https://doi.org/10.1088/0268-1242/16/10/103
33. 32. Shi, Z. Q., Wallace, R. L., & Anderson, W. A. (1991). High-barrier height Schottky diodes on N-InP by deposition on cooled substrates. Applied Physics Letters, 59(4), 446–448. https://doi.org/10.1063/1.105458
34. 33. Singh, J. (2000). Semiconductor Devices. John Wiley & Sons.
35. Soylu, M., & Abay, B. (2009). Barrier characteristics of gold Schottky contacts on moderately doped n-InP based on temperature dependent I–V and C–V measurements. Microelectronic Engineering, 86(1), 88–95. https://doi.org/10.1016/j.mee.2008.09.045
36. Soylu, M., Abay, B., & Onganer, Y. (2011). Electrical characteristics of Au/Pyronine-B/moderately doped n-type InP Schottky structures in a wide temperature range. Journal of Alloys and Compounds, 509(16), 5105–5111. https://doi.org/10.1016/j.jallcom.2011.01.183
37. Sugino, T., Ito, H., & Shirafuji, J. (1990). Barrier height enhancement of InP Schottky junctions by treatment with photo-decomposed PH3. Electronics Letters, 26(21), 1750. https://doi.org/10.1049/el:19901124
38. Sugino, T., Sakamoto, Y., Sumiguchi, T., Nomoto, K. N. K., & Shirafuji, J. S. J. (1993). Barrier Heights of Schottky Junctions on n-InP Treated with Phosphine Plasma. Japanese Journal of Applied Physics, 32(9A), L1196. https://doi.org/10.1143/jjap.32.l1196
39. Sullivan, J. P., Tung, R. T., Pinto, M. R., & Graham, W. R. (1991). Electron transport of inhomogeneous Schottky barriers: A numerical study. Journal of Applied Physics, 70(12), 7403–7424. https://doi.org/10.1063/1.349737
40. Sze, S. M. (1981). Physics of Semiconductor Devices. Wiley-Interscience.
41. Tung, R. T. (1992). Electron transport at metal-semiconductor interfaces: General theory. Physical Review. B, Condensed Matter, 45(23), 13509–13523. https://doi.org/10.1103/physrevb.45.13509 Van Der Ziel, A. (1968). Solid State Physical Electronics. Prentice Hall.