Atomic Layer Deposition of TiN Films by Alternate Supply of Tetrakis(ethylmethylamino)-Titanium and Ammonia

Abstract

Atomic layer deposition (ALD) of amorphous TiN films on SiO2 between 170°C and 210°C has been investigated by alternate supply of reactant sources, Ti[N(C2H5CH3)2]4 [tetrakis(ethylmethylamino)titanium:TEMAT] and NH3. Reactant sources were injected into the reactor in the following order:TEMAT vapor pulse, Ar gas pulse, NH3 gas pulse and Ar gas pulse. Film thickness per cycle was saturated at around 1.6 monolayers (ML) per cycle with sufficient pulse times of reactant sources at 200°C. The results suggest that film thickness per cycle could exceed 1 ML/cycle in ALD, and are explained by the rechemisorption mechanism of the reactant sources. An ideal linear relationship between number of cycles and film thickness is confirmed. As a result of surface limited reactions of ALD, step coverage was excellent. Particles caused by the gas phase reactions between TEMAT and NH3 were almost absent because TEMAT was segregated from NH3 by the Ar pulse. In spite of relatively low substrate temperature, carbon impurity was incorporated below 4 at.%.

Trimethylaluminum as a Reducing Agent in the Atomic Layer Deposition of Ti(Al)N Thin Films

“…As in the growth of TiN films using CVD, titanium alkyl amides have also been studied in ALD, and amorphous TiN films with an excellent step coverage were obtained from tetrakis(ethylmethylamino)titanium (TEMAT) and ammonia in a temperature range between 150 and 220 C. [35,36] The average deposition rate was 0.45 nm cycle ±1 , and most likely followed the self-limiting deposition mode typical for ALD. The resistivity, on the other hand, exhibited a dramatic increase as the deposition temperature was increased.…”

Characteristics of TiN thin films grown by ALD using TiCl4 and NH3

“…Although metal organic compounds such as tetrakis dimethyl-amino titanium (TDEAT), tetrakis diethyl-amino titanium (TDMAT) and tetrakis ethyl-methyl-amino titanium (TEMAT) have been investigated as titanium sources for TiN film deposition, poor quality and a relatively high resistivity of the film due to high content of carbon and oxygen in the deposited film have been reported [10]. Therefore, in the present study TiCl 4 , reported to have high vapor pressure and low electrical resistivity of the deposited film, and NH 3 were chosen as a titanium source and a reactant, respectively [6].…”

Preparation of TiN films by plasma assisted atomic layer deposition for copper metallization

“…The most widely investigated precursor of inorganic-based TiN ALD is titanium tetrachloride (TiCl 4 ). However, in the case of TiCl 4 -based TiN ALD, the deposition temperature is considered high [2][3][4]. On the other hand, in the case of MO TiN ALD, although the issues of deposition temperature and chlorine contamination are resolved, high resistivity of the films remains as a major drawback [5].…”