화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.154, No.6, G134-G140, 2007
Liquid injection atomic layer deposition of TiOx films using Ti[OCH(CH3)(2)](4)
TiOx films were prepared by liquid injection atomic layer deposition using titanium tetraisopropoxide (TTIP), Ti[OCH(CH3)(2)](4), dissolved in ethylcyclohexane (ECH). We analyzed the residual water content and the reaction with the TTIP for several solvents, choosing ECH for dissolving the TTIP because of the lowest residual water level and no ligand exchange reaction with the TTIP. TiOx films were deposited at 240 degrees C with a wide range of the TTIP solution injections per cycle. However, an ideal self-regulated growth was not achieved for the TiOx films due to a slow catalytic decomposition of the TTIP molecules followed by the exchange reaction with the underling layer. The contribution of the catalytic decompositions to the deposition rates was suppressed by increasing the injection frequency of the TTIP solution into the vaporizer. A rather independent deposition rate of the input of the TTIP solution was achieved by increasing the injection frequency to 4 Hz, while TiOx films deposited with a low injection frequency of 0.25 Hz showed almost linear film growth rate to the input of the TTIP solution. The deposited TiOx films were amorphous and clearly showed both unipolar and bipolar resistive switching behaviors, which are applicable to nonvolatile memory applications. (c) 2007 The Electrochemical Society.