Tetrakis Diethylamido Titanium Research Articles

High-speed deposition of titanium carbide coatings by laser-assisted metal–organic CVD

A semiconductor laser-assisted chemical vapor deposition (LCVD) of titanium carbide (TiCx) coatings on Al2O3 substrate using tetrakis (diethylamido) titanium (TDEAT) and C2H2 as source materials were investigated. The influences of laser power (PL) and pre-heating temperature (Tpre) on the microstructure and deposition rate of TiCx coatings were examined. Single phase of TiCx coatings were obtained at PL=100–200W. TiCx coatings had a cauliflower-like surface and columnar cross section. TiCx coatings in the present study had the highest Rdep (54μm/h) at a relative low Tdep than those of conventional CVD-TiCx coatings. The highest volume deposition rate (Vdep) of TiCx coatings was about 4.7×10−12m3s−1, which had 3–105 times larger deposition area and 1–4 order lower laser density than those of previous LCVD using CO2, Nd:YAG and argon ion laser.

Effect of the amido Ti precursors on the atomic layer deposition of TiN with NH3

The effect of the amide Ti precursors, tetrakis dimethyl amido titanium (TDMAT), tetrakis ethylmethyl amido titanium (TEMAT), and tetrakis diethyl amido titanium (TDEAT) on the atomic layer deposition of TiN film with ammonia was studied. Surface decomposition mechanism of each precursor was studied with in-situ Fourier transform infrared spectroscopy. It was confirmed that ethyl ligand in the precursor was more stable than methyl and the surface decomposition temperature of TDMAT, TEMAT, and TDEAT was 175, 200, and 250 °C on the SiO2 surface, respectively. The resistivity of the film was decreased with the increase in the substrate temperature due to the film crystallization. The TiN film deposited with TDMAT gave the lowest resistivity even though the atomic layer deposition temperature window was lowest due to the largest amount of carbon incorporation. It was confirmed that carbon incorporation leads to TiC formation and suppressed the postdeposition oxygen uptake possibly due to the elimination of vacancy in the film.

Selective Atomic Layer Deposition of TiO2 on Silicon/Copper-patterned Substrates

As microelectronic devices shrink, thinner diffusion barrier layers are needed to separate the copper and silicon substrates while leaving the copper vias open for conduction. Selective atomic layer deposition (ALD) of titanium dioxide(TiO2), a good barrier layer, onto silicon was studied by minimizing the exposure time to air of these substrates immediately before deposition. The minimized exposure time mimicked industrial conditions, where waiting before deposition is costly. Tetrakis(diethylamido)titanium (TDEAT) was used as the precursor, and water was the oxidizing agent. TDEAT was first deposited on silicon wafers using ALD to verify a steady, linear growth rate reported in the literature, and the measured rate of 0.9 ± 0.1 Å/cycle is consistent with values previously reported. Minimized exposure to air had no effect on the growth rate of TiO2 on silicon, and the effect on copper has yet to be determined.

Preparation of Stoichiometric TiN<sub>x</sub> Films by Laser CVD with Metalorganic Precursor

Nearly stoichiometric TiNx films were deposited on Al2O3 substrates by laser enhanced chemical vapor deposition (CVD) with tetrakis (diethylamido) titanium (TDEAT) and ammonia as the source materials. Emphases were given on the effects of laser power (PL) and pre-heating temperature (Tpre) on the composition and deposition rate of TiNx films. Single phase of TiNx films with columnar cross section were obtained. The ratio of N to Ti in TiNx films increased with increasing PL and was close to stoichiometric at PL > 150 W. The deposition rate of TiNx films with a depositing area of 300 mm2 was about 18-90 µm/h, which decreased with increasing PL and Tpre.

Laser chemical vapor deposition of titanium nitride films with tetrakis (diethylamido) titanium and ammonia system

Wide-area and thick titanium nitride (TiN x ) films were prepared on Al 2O 3 substrate by laser chemical vapor deposition (LCVD) using tetrakis (diethylamido) titanium (TDEAT) and ammonia (NH 3) as source materials. Effects of laser power ( P L) and pre-heating temperature ( T pre) on the composition, microstructure and deposition rate of TiN x films were investigated. (111) and (200) oriented TiN x films in a single phase were obtained. The lattice parameter and N to Ti ratio of the TiN x films slightly increased with increasing P L and was close to stoichiometric at P L > 150 W. TiN x films had a cauliflower-like surface and columnar cross section. The deposition rate of TiN x films increased from 42 to 90 µm/h at a depositing area of 10 mm by 10 mm substrate, decreasing with increasing P L and T pre. The highest volume deposition rate of TiN x films was about 10 2 to 10 5 times greater than those of previous LCVD using Nd:YAG laser, argon ion laser and excimer laser.

Atomic Vapor Deposition of TiN with Diluted Tetrakis (diethylamido) Titanium (TDEAT) for Phase Change Memory

We develop a 200mm Titanium Nitride (TiN) atomic vapor deposition (AVD) process for phase change memory (PCM). Diluted TDEAT is used for the deposition. By optimum the AVD parameters, we successfully develop the TiN process with accurately controllable deposition rate, good surface, stable resistivity and good repeatability. This process can be efficiently applied to PCM as the electrodes and electrode contacts.

Effect of NH 3 on the preparation of TiN x films by laser CVD using tetrakis-diethylamido-titanium

Titanium nitride (TiN x ) films were prepared by laser chemical vapor deposition (LCVD) with tetrakis-diethylamido-titanium (TDEAT) and NH 3 as the source materials. The effects of the fraction of ammonia ( F N H 3 ) on the microstructure, preferred orientation and deposition rate were investigated. Non-oriented TiN x films with a cauliflower-like texture were obtained without NH 3, whereas (1 1 1), (2 0 0) and (2 2 0) preferred TiN x films in a single phase with facetted and square textures were obtained with NH 3 gas. The lattice parameter decreased slightly with increasing F N H 3 . The deposition rate ( R dep) of TiN x films with a deposition area of about 300 mm 2 increased with increasing F N H 3 , and attained the highest value of 90 μm h −1 at F N H 3 = 0.5, laser power ( P L) = 100 W and deposition temperature ( T dep) = 597 °C.

Characterization of titanium oxynitride films deposited by low pressure chemical vapor deposition using amide Ti precursor

In this study, we investigate the use of an amide-based Ti-containing precursor, namely tetrakis(diethylamido)titanium (TDEAT) , for TiN x O y film deposition at low temperature. Traditionally, alkoxide-based Ti-containing precursor, such as titanium tetra-isopropoxide (TTIP), along with NH 3 is used for titanium oxynitride (TiN x O y ) film deposition. When TTIP is used, at low temperatures it is difficult to form TiN x O y films with high N/O ratios. In this study, by using TDEAT, TiN x O y films are deposited on H-passivated Si (100) substrates in a cold wall reactor at 300 °C and 106 Pa. Rutherford backscattering spectroscopy analysis shows nitrogen incorporation in the TiN x O y films to be as high as 28 at.%. X-ray photoelectron spectroscopy analysis of as-deposited films confirms the formation of . TiN x O y , while Fourier transform infrared and Raman spectra indicate that the films have amorphous structure. Moreover, there is no detectable bulk carbon impurity and no SiO 2 formation at the TiN x O y /Si interface. Upon annealing the as-deposited films in air at 750 °C for 30 min, they oxidize to TiO 2 and crystallize to form a rutile structure with a small amount of anatase phase. Based on these results, TDEAT appears to be a promising precursor for both TiN x O y and TiO 2 film deposition.

Tetrakis(diethylamido) titanium (TDEAT) interactions with SiO 2 and Cu substrates

X-ray photoelectron spectroscopy (XPS) is used to characterize the chemical interactions of tetrakis(diethylamido) titanium (TDEAT) with SiO 2 and Cu surfaces under ultrahigh vacuum (UHV) conditions. XPS studies show that TDEAT dissociatively chemisorbs on SiO 2 at room temperature or above, resulting in TiN bond scission, and TiO bond formation. No Ti carbide or Si carbide formation is observed. In the presence of co-adsorbed NH 3, TiN bond formation is enhanced and is stable at temperature up to 900 K in UHV. Continuous exposures of TDEAT on SiO 2 at 500 K produce both Ti oxides and nitride formation. The presence of an overpressure of NH 3 enhances Ti nitride formation. In contrast, TDEAT physisorbed on Cu at 120 K and annealed to 500 K results in desorption of Ti-containing species from the surface. Successive exposures of TDEAT on Cu at 500 K yield a Ti-alkyl reaction product. The presence of NH 3 does not significantly alter TDEAT interaction with Cu.

Low-temperature growth of Ti(C,N) thin films on D2 steel and Si(100) substrates by plasma-enhanced metalorganic chemical vapor deposition

We have deposited Ti(C,N) thin films on Si(100) and D2 steel substrates in the temperature range of 200–300 °C using tetrakis diethylamidotitanium (TDEAT) and titanium isopropoxide (TIP) by pulsed dc plasma-enhanced metalorganic chemical vapor deposition (PEMOCVD). Radical formation and ionization behaviors in plasma are analyzed in situ by optical emission spectroscopy at various pulsed bias voltages and gas conditions. H2 and He+H2 gases are used as carrier gases to compare plasma parameters, and the effect of N2 and NH3 as reactive gas is also evaluated by the reduction of the C content of the films. Polycrystalline Ti(C,N) thin films were successfully grown on either D2 steel or Si(100) surfaces with TDEAT at temperatures as low as 200 °C. For TIP, however, only TiOCN thin films were obtained on Si(100) substrates. The best deposition process is evident for H2 and N2 gas atmospheres and bias voltage of 600 V. The higher film hardness is about 1760 Hk 0.01, but depends on gas species and bias voltage. Compared to TiN films, the Ti(C,N) film grown by PEMOCVD has very good conformability; the step coverage exceeds 85%, with an aspect ratio of more than 3.

Comparison of Tetrakis(dimethylamido)titanium and Tetrakis(diethylamido)titanium as Precursors for Metallorganic Chemical Vapor Deposition of Titanium Nitride

Tetrakis(dimethylamido)titanium (TDMAT) and tetrakis(diethylamido)titanium (TDEAT) as precursors for metallorganic chemical vapor deposition of TiN were compared. H nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC) were used to study the thermal decomposition behavior of the liquid‐phase compounds. NMR spectra showed that TDEAT was thermally stable up to 220°C, while TDMAT began to decompose over 140°C. DSC results also confirmed that TDEAT had a better thermal stability than TDMAT. The gas‐phase reaction mechanism of the compounds monitored by in situ Fourier transform infrared spectroscopy and TDEAT was decomposed at higher temperature due to its steric hindrance effect. TDMAT and TDEAT had a similar dissociation mechanism in the liquid and gas phase. Both precursors were decomposed at high temperatures into Ti metal and dialkylamine. The deposition rate of TiN was higher with TDMAT than with TDEAT, and TiN films deposited with TDMAT showed lower carbon content and smooth surface morphology. © 1999 The Electrochemical Society. All rights reserved.

Investigating the process latitude of a low temperature metalorganic chemical vapor deposition TiNitride process

A design of experiments was used to characterize a metalorganic chemical vapor deposition (MOCVD) TiN production process and hardware. The factors evaluated included pedestal temperature, tetrakis diethylamido titanium (TDEAT) flow, reactor pressure, ammonia flow, and nitrogen purge flow. Responses include density, resistivity, deposition rate, thickness uniformity, step coverage, stress, resistance stability, and particles. All factors studied but the nitrogen purge had some first order effect on the responses investigated. Temperature has the most significant effect on the overall film quality and step coverage. Increasing temperature increases the density and lowers the resistivity of the film while reducing the step coverage. Pressure is a dominant factor and effects all the responses studied. Increasing the pressure serves to improve the film quality and step coverage. Ammonia used at high rates increases the density of the film while reducing the deposition rate and thickness nonuniformity. The TDEAT flow primarily controls the deposition rate of the system; too high a flow can result in an increase in the resistivity and a drop in film density. Characterization of the CVD TiN process indicated that for the factor ranges studied the center point process is manufacturable and controllable. All of the responses were found to be within acceptable ranges.

Laser-assisted chemical vapor deposition of titanium nitride films

We used a 193 nm ArF excimer laser to assist chemical vapor deposition of titanium nitride (TiN) films on Si (100) and SiO2. The source gases were tetrakis(dimethylamido)titanium (TDMAT) or tetrakis(diethylamido)titanium (TDEAT) mixed with ammonia. A correct stoichiometry was confirmed from Auger spectra. The laser helped to enhance TiN deposition rates at low temperatures (100 °C for TDMAT-NH3 and 200 °C for TDEAT-NH3). At higher temperatures the deposition rates decreased with an increasing laser energy density. Under irradiation the electrical resistivity of the TiN films was lowered. The laser-induced effect on electrical resistivity was particularly pronounced at low temperatures. A good conformality of the TiN films for contact holes with high aspect ratios was demonstrated.

Effect of H2 and N2 in the remote plasma enhanced metal organic chemical vapor deposition of TiN from tetrakis-diethyl-amido-titanium

The effect of H2 and N2 in the plasma in the remote plasma enhanced metal organic chemical vapor deposition (MOCVD) of TiN from tetrakis-diethyl-amido-titanium (TDEAT) was studied. The growth rate with H2 in the plasma is about four times higher than that with N2 in the plasma and both processes required similar activation energies, 9.70 and 9.33 kcal/mol, respectively. Carbon was incorporated as TiC and hydrocarbons in the TiN film and the fraction of carbon as TiC phase was higher using H2 plasma. The film deposited with H2 in the plasma had a lower resistivity due to the lower level of carbon incorporation in the film. The surface of the film deposited with N2 in the plasma was rougher. It was believed that hydrogen radicals reacted with nitrogen atoms in TDEAT and produced Ti-rich film with lower carbon contents while nitrogen radicals produced films containing much more hydrocarbon.

Remote plasma enhanced metal organic chemical vapor deposition of TiN for diffusion barrier

TiN films were deposited with remote plasma metal organic chemical vapor deposition (MOCVD) from tetrakis-diethyl-amido-titanium (TDEAT) at substrate temperature of 250–500°C and plasma power of 20–80 W. The growth rate using N2 plasma is slower than that with H2 plasma and showed 9.33 kcal/mol of activation energy. In the range of 350–400°C., higher crystallinity and surface roughness were observed and resistivity was relatively low. As the temperature increased to 500°C., randomely oriented structure and smooth surface with higher resistivity were obtained. At low deposition temperature, carbon was incorporated as TiC phase, as the deposition temperature increases, carbon was found as hydrocarbon. At 40 W of plasma power, higher crystallinity and rough surface with lower resistivity were obtained and increasing the plasma power to 80 W leads to low crystallinity, smooth surface and higher resistivity. It may be due to the incorporation of hydrocarbon decomposed in the gas phase. Surface roughness was found to be related to the crystallinity of the film.

Atmospheric Pressure Chemical Vapor Deposition of Titanium Nitride from Tetrakis (diethylamido) Titanium and Ammonia

Titanium nitride (TiN) films were made from tetrakis (diethylamido) titanium (TDEAT) and ammonia by atmospheric pressure chemical vapor deposition (APCVD). Growth rates, stoichiometries, and resistivities were studied as a function of temperature and ammonia: TDEAT ratios. Films were characterized by four‐point probe, Rutherford backscattering, forward (elastic) recoil, and x‐ray photoelectron spectroscopies. TDEAT was found to have a higher deposition efficiency (>1/3), and slower reaction kinetics than the related (TDMAT) compound. Higher temperatures and relative concentrations were necessary to achieve similar growth rates. Though growth was slower than when using TDMAT, films from TDEAT had higher step coverage, lower resistivities (<1000 μΩ‐cm) and were more stable with time. These films are promising candidates for diffusion barriers in 0.25 μm ULSI device technologies.

Thermal Metalorganic Chemical Vapor Deposition of Ti-Si-N Films for Diffusion Barrier Applications

AbstractStructurally disordered refractory ternary films such as titanium silicon nitride (Ti-Si-N) have potential as advanced diffusion barriers in future ULSI metallization schemes. Here we present results on purely thermal metalorganic chemical vapor deposition (CVD) of Ti-Si-N. At temperatures between 300 and 450°C, tetrakis(diethylamido)titanium (TDEAT), silane, and ammonia react to grow Ti-Si-N films with Si contents of 0-20 at.%. Typical impurity contents are 5-10 at.%H and 0.5 to 1.5 at.% C, with no O or other impurities detected in the bulk of the film. Although the film resistivity increases with increasing Si content, it remains below 1000 μΩ-cm for films with less than 5 at.% Si. These films are promising candidates for advanced diffusion barriers.

Step Coverage and Material Properties of CVD Titanium Nitride Films from TDMAT and TDEAT Organic Precursors

Titanium nitride (TiN) films serve an important function as an adhesion layer and diffusion barrier in contact and via plug structures of ULSI devices. In this work, TiN films were deposited by chemical vapor deposition (CVD) at atmospheric pressure using the tetrakis (dimethylamido) titanium (TDMAT) and tetrakis (diethylamido) titanium (TDEAT) organic precursors over a range of temperatures and ammonia partial pressures. The step coverage and morphology of these films was evaluated at these various conditions by SEM of cross-sectioned contacts. In addition, material properties such as resistivity. surface roughness, and stoichiometry were assessed at some of the operating conditions.