Influence of growth temperature on the structure and electrical properties of high‐permittivity TiO₂ films in TiCl₄‐H₂O and TiCl₄‐O₃ atomic‐layer‐deposition processes

Abstract

The influence of the growth temperature on structure and the electrical properties of TiO 2 thin films deposited from TiCl 4 and H 2 O and from TiCl 4 and O 3 was investigated in the temperature range of 150-500 8C. The high-permittivity rutile phase of TiO 2 was obtained on RuO 2 in both processes at 225 8C and higher substrate temperatures. The films deposited on Si contained rutile only when were deposited from TiCl 4 and H 2 O at temperatures above 425 8C. Comparison of the films grown on RuO 2 revealed superior electrical performance of those deposited from TiCl 4 and O 3 . Although the k values ranging from 100 to 130 in the Pt/TiO 2 /RuO 2 structures were somewhat lower for these films than for the films deposited from TiCl 4 and H 2 O, the former process resulted in lower leakage current densities at similar capacitance effective thicknesses (CET). The leakage current density as low as 6.6 Â 10 À8 A cm À2 at 0.8 V and CET ¼ 0.41 nm was obtained for films deposited from TiCl 4 and O 3 at 350 8C.

Effect of Growth Temperature during the Atomic Layer Deposition of the SrTiO3 Seed Layer on the Properties of RuO2/SrTiO3/Ru Capacitors for Dynamic Random Access Memory Applications

“…Due to the large t ox i of the LT seed layer capacitors, however, caused by the small k bulk(seed) , the minimum t ox with an acceptable leakage current was larger than that of the capacitors with an HT seed layer by ∼0.39 nm, which is a critical demerit of the LT seed process. The obtained minimum t ox value is still higher than the binary TiO 2 -based capacitor ( t ox ∼ 0.41 nm) . Since the permittivity of single crystal STO is reported about two times higher than that of TiO 2 , the optimized STO ALD process is supposed to show lower t ox value than TiO 2 process. , In fact, the SrRuO 3 /STO/SrRuO 3 capacitor fabricated by sputtering with no vacuum break between the different film growths a minimum t ox of 0.35 nm with a leakage current of 1 × 10 –7 A/cm 2 at 1.0 V has been reported .…”

Effect of substrate type on structure of TiO2 thin film deposited by atomic layer deposition technique

“…Figure 2 shows the GIXRD patterns of TiO 2 thin films deposited on Si(100) substrate for process temperatures of 300 ºC and 450 ºC. These tempera-tures were selected based on literature [12,19,23] and observations by us as the optimum temperatures to obtain the anatase (around 250-300°C) and rutile phase (higher than 400°C) with a high degree of crystallinity. It is possible to see from Fig.…”

“…Due to aforementioned properties, TiO 2 thin films with rutile structure are considered as promising candidates for DRAM capacitor dielectrics by the International Technology Roadmap for Semiconductors (ITRS) [12,13]. However, its synthesis is easier at temperatures higher than 500°C for most of the deposition processes of thin films, namely, magnetron sputtering [1,14], chemical vapor deposition -CVD [15], plasma enhanced chemical vapor deposition -PECVD [16], atomic layer deposition -ALD [17], among others.…”

Titanium dioxide thin films by atomic layer deposition: a review

“…The data illustrated in color in one of the figures, is shown in black in all the other figures. The data is retrieved from the following references: TiCl4/H2O [13,17,19,22,23,28,30,37,38,42,44,45,56,58,83,88,94,123,124], TiCl4/H2O2 [334][335][336], TiCl4/O3 [271],TiCl4/O2 plasma [344,345], TiCl4/MeOH [347],TiI4/H2O [348], TiI4/H2O2 [352,354], TiI4/O2 [356], TiF4/H2O [357].…”