Fast thermal annealing for manufacturing of silicon diodes and photodiodes

The influence of rapid thermal annealing (RTA) in hydrogen atmosphere on ohmic properties of double-layer composition Ti/Au as contact on р⁺-Si was investigated. Based on experimental results it was confirmed that RTA at 340 °С for 20 s in hydrogen atmosphere allows to obtain an ohmic contact with the minimum of resistivity. This is due to titanium silicides formation on the Si/Ti interface. It also known silicides formation on Si-interface with other transition metals such as Ni, Pd and Cr, which determines the application of RTA for obtaining ohmic contacts based on them. The applicability of RTA for manufacture technology of silicon diodes to reduce the serial resistance, which leads to increased yield rate of diodes, was confirmed by applying on a limited diode p⁺–n as an example.

Also, the influence of RTA in hydrogen atmosphere on a dark current was investigated by applying on a silicon multi-element p–i–n photosensitive element (PE) as an example. Based on experimental results it was confirmed that RTA at 450 °С for 5 s improved dark current of the photosensitive areas and the guard ring and as a result increased yield rate of photodiodes. This is due to decreasing of the density of surface states and stabilization of charge properties of the SiO₂/p-Si interface through saturation of dangling Si-bonds with hydrogen. This confirmed the applicability of RTA in hydrogen atmosphere for manufacture technology of photodiodes on high-resistance p-Si to reduce its dark current.

1. Chen L.J. (ed.). Silicide technology for integrated circuits. London: Institution of Electrical Engineers; 2004. 279 p.

2. Gambino J.P., Colgan E.G. Silicides and ohmic contacts. Materials Chemistry and Physics. 1998; 52(2): 99—146. https://doi.org/10.1016/S0254-0584(98)80014-X

3. Vavilov K., Kiselev V.F., Mukashev B.N. Defects in silicon and on its surface. Moscow: Nauka; 1990. 216 p. (In Russ.)

4. Hiraki A. Low temperature reactions at Si/metal interfaces; What is going on at the interfaces? Surface Science Reports. 1983; 3(7): 357—412. https://doi.org/10.1016/0167-5729(84)90003-7

5. Chernyaev V.N. Technology of production of integrated circuits and microprocessors. Moscow: Radio i svyaz'; 1987. 464 p. (In Russ.)

6. Gritsenko V.A. Structures of silicon/oxide and nitride/oxide interfaces. Uspekhi Fizicheskikh Nauk; 2009; 179(9): 921—930. (In Russ.). https://doi.org/10.3367/UFNr.0179.200909a.0921

7. Burlakov R.B. On determination of contact resistivity by tlm method with rectangular contacts to semiconductors. Vestnik Omskogo universiteta = Herald of Omsk University. 2018; 23(4): 78—86. (In Russ.). https://doi.org/10.25513/1812-3996

8. Aldosari H.M., Cooley K.A., Yu Sh.-Y., Simchi H., Mohney S.E. Very low-resistance Mo-based ohmic contacts to GeTe. Journal of Applied Physics. 2017; 122(17): 175302. https://doi.org/https://doi.org/10.1063/1.4990407

9. Holland A.S., Pan Y., Alnassar M.S.N., Luong St. Circular test structures for determining the specific contact resistance of ohmic contacts. Facta Universitatis-series: Electronics and Energetics. 2017; 30(3): 313—326. https://doi.org/10.2298/FUEE1703313H

10. Gupta S., Paramahans M.P., Mishra K.R., Nainani A., Abraham M. C., Lodha S. Contact resistivity reduction through interfacial layer doping in metal-interfacial layer-semiconductor contacts. Journal of Applied Physics. 2013; 113(23): 234505. https://doi.org/10.1063/1.4811340

11. Soldatenkov F.Y., Sorokina S.V., Timoshina N.K., Khvostikov V.P., Zadiranov Y.M., Rastegaeva M.G., Usikova A.A. A decrease in ohmic losses and an increase in power in GaSb photovoltaic converters. Semiconductors. 2011; 45(9): 1219—1226.

12. Jang H.W., Kim K.H., Kim J.K., Hwang S.-W., Yang J.J., Lee K.J., Son S.-J., Lee J.-L. Low-resistance and thermally stable ohmic contact on p-type GaN using Pd/Ni metallization. Applied Physics Letters. 2001; 79(12): 1822—1824. https://doi.org/10.1063/1.1403660

13. Lu C., Chen H., Lv X., Xie X., Mohammad S.N. Temperature and doping-dependent resistivity of Ti/Au/Pd/Au multilayer ohmic contact ton-GaN. Journal of Applied Physics. 2002; 91(11): 9218—9224. https://doi.org/10.1063/1.1471390

14. Andreev A.N., Rastegaeva M.G., Rastegaev V.P., Reshanov S.A. On calculation of current spreading in the semiconductor under specific contact resistance measurements. Semiconductors. 1998; 32(7): 832—838. (In Russ.)

15. Dric M.E. (ed.). Properties of elements. Moscow: Metallurgiya; 1985. 672 p.

16. Berezin B.Ya., Kac S.A., Kenisarin M.M., Chekhovskoj V.Ya. Heat and melting point of titanium. Teplofizika vysokih temperature. 1974; 12(3): 524—529. (In Russ.)

17. Bestugin A.R., Filonov O.M., Kirshina I.A., Andreeva E.V. Features of designing the technological process for manufacturing the inertial element of a micromechanical sensor on surface acoustic waves. In: III Inter. scient.-techn. conf. "Radio engineering, electronics and communication (REIS-2015)". Omsk, October 6–8, 2015. Moscow: OOO Izdatel'skii dom “Nauka”; 2015. P. 438—443. (In Russ.)

18. Filachev A.M., Taubkin I.I., Trishenkov M.A. Solid-state photoelectronics. Photodiodes. Moscow: Fizmatkniga; 2011. 446 p. (In Russ.)

19. Kurnosov A.I., Yudin V.V. Technology of production of semiconductor devices and integrated circuits. Moscow: Vyssh. Shkola; 1986. 368 p. (In Russ.)

20. Koledov L.A. Technology and design of microcircuits, microprocessors and microassemblies. Moscow: Radio i svyaz'; 1989. 400 p. (In Russ.)

21. Patent (RU) No 2015630066 C1, Liberova G.V., Markova T.L., Rybakov A.V. Crystal of silicon limiting diode. Appl.: 16.04.2015; publ.: 20.07.2015. (In Russ.)

22. Patent (RU) No 2790272 С1, MPC H01L 21/28, H01L 31/18. Kim A.S., Serko N.A. Method for forming ohmic contacts to silicon by means of a bilayer Ti/Au metallisation system. Appl.: 03.08.2022; publ.: 15.02.2023. (In Russ.)

23. Baranochnikov M.L. Receivers and radiation detectors. Directory. Moscow: DMK Press; 2012. 640 p. (In Russ.)

24. Description of the utility model for patent (RU) No. 205303 U1, IPC H01L 31/028. Kim A.S., Kolkiy A.N. Multi-site silicon p-i-n photodiode with a two-layer dielectric film. Appl.: 10.03.2021; publ.: 08.07.2021. (In Russ.)