Advanced cyclopentadienyl precursors for atomic layer deposition of ZrO2 thin films

Abstract

ZrO 2 thin films were grown onto silicon (100) substrates by atomic layer deposition (ALD) using novel cyclopentadienyl-type precursors, namely (CpMe) 2 ZrMe 2 and (CpMe) 2 Zr(OMe)Me (Cp ¼ cyclopentadienyl, C 5 H 5 ) together with ozone as the oxygen source. Growth characteristics were studied in the temperature range of 250 to 500 C. An ALD-type self-limiting growth mode was verified for both processes at 350 C where highly conformal films were deposited onto high aspect ratio trenches. Signs of thermal decomposition were not observed at or below 400 C, a temperature considerably exceeding the thermal decomposition temperature of the Zr-alkylamides. Processing parameters were optimised at 350 C, where deposition rates of 0.55 and 0.65 A ˚cycle À1 were obtained for (CpMe) 2 ZrMe 2 /O 3 and (CpMe) 2 Zr(OMe)Me/O 3 , respectively. The films grown from both precursors were stoichiometric and polycrystalline with an increasing contribution from the metastable cubic phase with decreasing film thickness. In the films grown from (CpMe) 2 ZrMe 2 , the breakdown field did not essentially depend on the film thickness, whereas in the films grown from (CpMe) 2 Zr(OMe)Me the structural homogeneity and breakdown field increased with decreasing film thickness. The films exhibited good capacitive properties that were characteristic of insulating oxides and did not essentially depend on the precursor chemistry.

Electrical properties of thin zirconium and hafnium oxide high-k gate dielectrics grown by atomic layer deposition from cyclopentadienyl and ozone precursors

“…%͒. 11 Hydrogen content could not be analyzed. However, the oxygen to zirconium atomic ratio could reach 2.06-2.07 in the films grown from ͑CpMe͒ 2 Zr͑OMe͒Me at 300°C and in the films grown from ͑CpMe͒ 2 ZrMe 2 at 350°C, 11 referring to the possible presence of hydroxyl groups or carbonates, slightly increasing the relative content of oxygen.…”

“…Atomic layer deposition ͑ALD͒ of ZrO 2 and HfO 2 films has been realized using different precursors, most often or traditionally from chlorides, [3][4][5] but also from alternative, e.g., organometallic cyclopentadienyl-based precursors. [6][7][8][9][10][11] Good-quality ZrO 2 and HfO 2 films can be grown using ALD processes established for ͑CpMe͒ 2 ZrMe 2 , 9,11 ͑CpMe͒ 2 Zr͑OMe͒Me, 9,11 ͑CpMe͒ 2 Hf͑OMe͒Me, 9,10 and O 3 as precursors. ͑CpMe͒ 2 ZrMe 2 may allow better stability of the growth rate against temperature parametrization, 11 whereas the ͑CpMe͒ 2 Hf͑OMe͒Me tended to allow relatively higher growth rates 11 and, possibly, stronger contribution from cubic/tetragonal phases in the films grown.…”

“…[6][7][8][9][10][11] Good-quality ZrO 2 and HfO 2 films can be grown using ALD processes established for ͑CpMe͒ 2 ZrMe 2 , 9,11 ͑CpMe͒ 2 Zr͑OMe͒Me, 9,11 ͑CpMe͒ 2 Hf͑OMe͒Me, 9,10 and O 3 as precursors. ͑CpMe͒ 2 ZrMe 2 may allow better stability of the growth rate against temperature parametrization, 11 whereas the ͑CpMe͒ 2 Hf͑OMe͒Me tended to allow relatively higher growth rates 11 and, possibly, stronger contribution from cubic/tetragonal phases in the films grown. 10 At the same time, also lower leakage was achieved in the ZrO 2 grown from ͑CpMe͒ 2 Zr͑OMe͒Me.…”

Atomic Layer Deposition of High‐k Oxides of the Group 4 Metals for Memory Applications

“…[74,75] For ZrO 2 film growth with ozone or water as the oxygen source, liquid (MeCp) 2 Zr (OMe)Me was developed. [55,56] Highly conformal films were obtained with growth rates of about 0.6 Ǻ cycle À1 , which is somewhat lower than in the case of Zr-alkylamides. The precursor was found to be thermally stable up to 375 8C and its reaction mechanisms with both water and ozone have been studied in detail.…”

ZrO2Thin Film Deposition on TiN by Plasma Enhanced Atomic Layer Deposition Using Cyclopentadienyltris(dimetylamino)zirconium

“…However, the growth rate (in ALD mode) remains lower than those obtained with alkylamides precursors 11 and the presz E-mail: vincent.jousseaume@cea.fr ence of organic residues due to the incomplete ligand removal is often reported. 10,11,17 Plasma Enhanced ALD (PEALD) is a deposition technique commonly used in the microelectronic industry, which allows, in general, high deposition rates at low deposition temperature. PEALD was successfully used for the fabrication of a ZrO 2 based capacitor with TEMAZ and an oxygen plasma source.…”