Rapid Thermal Annealing Equipment Research Articles

Characteristics of Al-doped ZnO films annealed at various temperatures for InGaZnO-based thin-film transistors

Aluminum-doped ZnO (ZnO:Al, AZO) thin-films were deposited using a pulsed DC unbalanced magnetron sputtering system. The deposited AZO films were annealed in N2 ambient at various temperatures using a rapid thermal annealing equipment. The influence of the annealing temperature on the structural, electrical, and optical properties of the AZO films was experimentally investigated and the effect of the conductivity of the AZO source/drain (S/D) electrode on the device performance of an oxide-thin film transistor (TFT) was tested. Increasing the annealing temperature resulted in an improvement of the crystallinity of the films. Increasing grain size was found to lead to an increase in the conductivity of the AZO films. The a-IGZO TFTs fabricated with the annealed AZO S/D electrodes showed good performance. Consequently, the performance of the TFT was influenced by the conductivity of the AZO film, which was related to its structural properties.

Preparation of Cu2ZnSnS4 thin films via electrochemical deposition and rapid thermal annealing

We fabricated metallic Cu–Zn–Sn (CZT) precursor thin films via electrochemical deposition from aqueous metal salt solution on Mo-coated soda-lime glass substrates, and the influence of the subsequent sulfurization condition on the morphology, composition and structure of the final Cu2ZnSnS4 (CZTS) thin films was investigated. A rapid thermal annealing equipment was used for a systematic control of the sulfurization process parameters. The as-deposited films are composed of binary metallic alloys, which can be converted to the highly crystalline CZTS phase after sulfurization at temperatures above 500°C. The composition of the CZT film barely changes during the sulfurization, and a small amount of CuS-based secondary phases exists even at 550°C. However, a quick post-annealing KCN treatment effectively and selectively removes the secondary phase, evidenced by the Raman spectroscopy and elemental.

Characterization of Rapid Thermal and Micro-Wave Annealed Germanium Thin Films Grown by E-Beam Evaporation on Glass Substrates

In this paper, we used the electron beam (e-beam) evaporation to deposit Ge thin film on glass, and used microwave annealing (MWA) system of 5.8 GHz frequency for thin film crystallization. Then, we compared the MWA experiment results of sample sheet resistance (Rs), crystallization strength and cross section with those using traditional rapid thermal annealing (RTA) equipment. We found that MWA can get poly-Ge thin film with (111), (220) and (311) crystallization directions and optimal Rs at a temperature of about 450 ° C without affecting the film thickness. By comparison, RTA equipment can only reduce the sample Rs at least temperature of 550oC.

The effects of annealing temperature on the characteristics of carbon counter electrodes for dye-sensitized solar cells

The carbon films have been deposited by unbalanced magnetron sputtering (UBMS) at room temperature. The deposited carbon films have been post-annealed at temperatures ranging from 400 °C to 600 °C in increments of 100 °C using rapid thermal annealing equipment in vacuum ambient. The variations in microstructure, surface and electrical properties of carbon films with various annealing temperature were investigated by using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and hall-effect measurement. In this paper, we proposed that annealed carbon films as the counter electrode in a dye-sensitized solar cell (DSSCs). We investigated the electrical performance of DSSCs using carbon counter electrodes prepared with various annealing temperatures. For the DSSC using the annealed carbon counter electrode prepared at 600 °C annealing temperature, we obtained the best performance of Jsc = 10.57 mA/cm 2, Voc = 730 mV, FF = 64.9%, and η = 5.0%.

Reduction in resistivity of 50 nm wide Cu wire by high heating rate and short time annealing utilizing misorientation energy

The resistivities and microstructures for 50 nm Cu wires fabricated by high heating rate (3 K/s) and short time (1 min) annealing using infrared rapid thermal annealing equipment have been investigated as a function of annealing temperature and compared to those properties for wires fabricated by a slow heating rate (0.08 K/s), long time (30 min) conventional H2 annealing process. The resistivity of wires annealed by the new process decreased substantially with increasing annealing temperature from 573 to 773 K. The resistivity had its lowest value between 773 and 873 K, and it increased rapidly with annealing temperature above 923 K. The average ρ value was 2.98 μΩ cm for 773 K new process wires, whereas average ρ values were about 3.55 μΩ cm for 573 K and 3.42 μΩ cm for 673 K conventionally H2 annealed wires. This resistivity value for the new process wires was about 16% lower than the value for wires annealed at 573 K and 13% lower than the value for the wires annealed at 673 K by the conventional H2 annealing process. The substantial resistivity decrease in the new process Cu wires is mainly attributed to uniform grain size coarsening and high (111) orientation effects by the high temperature and high rate heating, while the resistivity increase at higher heating temperatures above 923 K for new process wires is mainly attributed to the reaction between Cu and Ta/TaN barriers; the greater the extent of the reaction, the higher the resistivity.

The effect of annealing on Al-doped ZnO films deposited by RF magnetron sputtering method for transparent electrodes

In this study, transparent conducting Al-doped zinc oxide (AZO) films with a thickness of 150 nm were prepared on Corning glass substrates by the RF magnetron sputtering with using a ZnO:Al (Al 2O 3: 2 wt.%) target at room temperature. This study investigated the effects of the post-annealing temperature and the annealing ambient on the structural, electrical and optical properties of the AZO films. The films were annealed at temperatures ranging from 300 to 500 °C in steps of 100 °C by using rapid thermal annealing equipment in oxygen. The thicknesses of the films were observed by field emission scanning electron microscopy (FE-SEM); their grain size was calculated from the X-ray diffraction (XRD) spectra using the Scherrer equation. XRD measurements showed the AZO films to be crystallized with strong (002) orientation as substrate temperature increases over 300 °C. Their electrical properties were investigated by using the Hall measurement and their transmittance was measured by UV–vis spectrometry. The AZO film annealed at the 500 °C in oxygen showed an electrical resistivity of 2.24 × 10 − 3 Ω cm and a very high transmittance of 93.5% which were decreased about one order and increased about 9.4%, respectively, compared with as-deposited AZO film.

The effect of thermal annealing on the structural and mechanical properties of a-C:H thin films prepared by the CFUBM magnetron sputtering method

a-C:H films were prepared by closed-field unbalanced magnetron (CFUBM) sputtering on silicon substrates using argon (Ar) and acetylene (C 2H 2) gases, and the effects of post-annealing temperature on structural and mechanical properties were investigated. Films were annealed at temperatures ranging from 300 °C to 700 °C in increments of 200 °C using rapid thermal annealing equipment in vacuum ambient. Variations in microstructure were examined using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Surface and mechanical properties were investigated by atomic force microscopy (AFM), nano-indentation, residual stress tester, and nano-scratch tester. We found that the mechanical properties of a-C:H films deteriorated with increased annealing temperature.

The effect of annealing on the properties of diamond-like carbon protective antireflection coatings

In addition to its similarity to genuine diamond film, diamond-like carbon (DLC) film has many advantages, including its wide band gap and variable refractive index. Therefore, as one of the diverse applications, DLC film can be utilized as a protective coating for IR windows and an anti-reflective coating for solar cells. For this study, DLC films were prepared by the radio frequency-plasma enhanced chemical vapor deposition (RF-PECVD) method on silicon substrates using methane (CH 4) and hydrogen (H 2) gas. We examined the effects of the post-annealing temperature and the annealing ambient on structural, electrical and optical properties of DLC films. The films were annealed at temperatures ranging from 300 to 900 °C in steps of 200 °C using rapid thermal annealing equipment in nitrogen ambients. The thickness of the film was observed by scanning electron microscopy (SEM) and surface profile analysis. The variation of structure according to the annealing treatment was examined using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). The reflectance of DLC thin film was investigated by UV–vis spectrometry and its electrical properties were investigated using a four point probe and I– V meter. The carrier lifetime of the film was also checked.

Activation Treatment of Ion Implanted Dopants Using Hybrid Super RTA Equipment

We perform rapid thermal annealing (RTA) on areas as large as 2-inch φ (diameter) at high temperature using the hybrid super RTA (HS-RTA) equipment. The HS-RTA equipment consists of an infrared annealing unit and a RF induction annealing unit in order to uniformly anneal over 2-inch φ susceptor. As a result of annealing by the HS-RTA equipment, the temperature is elevated from RT to peak temperature (~1800°C) for less than 1 min, remain stable at annealing temperature for 30s and falls from peak temperature to 1000°C within less than 20s. The temperature distributions on a 2-inch φ susceptor are ±10°C, ±33°C and ±55°C at 1565°C, 1671°C and 1752°C, respectively. Phosphorus (P) ion implanted silicon carbide (SiC) samples are used to evaluate the performance of the HS-RTA equipment. The five implanted samples placed on the 2-inch φ susceptor are annealed for 30s at 1565°C, 1671°C and 1752°C. The mean sheet resistances of the 5 samples annealed at 1565°C, 1671°C and 1752°C are 92.6Ω/, 82.6Ω/ and 75.5Ω/, respectively. The sheet resistance uniformities are 9.9%, 7.9% and 9.3%. The average roughness (Ra) is calculated from 10 μm square Atomic Force Microscopy (AFM) image. Ra values of the samples annealed at 1565°C, 1671°C and 1752°C are 2.399 nm, 2.408 nm and 3.282 nm, respectively.

Effect of ramp rates during rapid thermal annealing of ion implanted boron for formation of ultra-shallow junctions

Over the last couple of years, manufacturers of rapid thermal annealing (RTA) equipment have been aggressively developing lamp-based furnaces capable of achieving ramp-up rates of the order of hundreds of degrees per second. One of the driving forces for such a strategy was the experimental demonstration of 30 nm p-type junctions using a ≈400°C/s ramp-up rate during a spike-anneal (zero soak-time at temperature). It was proposed that the ultra-fast ramp-up was suppressing transient enhanced diffusion (TED) of boron caused by implantation damage. Ultra-fast ramp rate capability was thus embraced as an essential requirement for the next generation of RTA equipment. In this paper, we review more recent experimental data examining the effect of the ramp-up rate during spike- and soak-anneals on enhanced diffusion and ultra-shallow junction formation. The advantage of increasing the ramp-up rate (above ≈50°C/s) is found to be appreciable only during spike-anneals of the shallowest implants. Since TED naturally decreases with decreasing implantation depth, it follows that the observed advantage of a fast ramp-up does not arise from a so-called suppression of TED but from a straightforward reduction of the thermal budget. Since the temperature ramp-down is in practice limited to a rate much smaller than the achievable ramp-up rates (≈75°C/s vs. ≈400°C/s, respectively), a point of diminishing return is quickly reached when attempting to decrease dopant diffusion by increasing the ramp-up rate only. The advantage of a fast ramp-up is similarly mitigated by the finite minimum soak-time achievable in practice, as well as by decreased process control at faster ramp-up rates. While it is apparent that spike-anneals can minimize dopant diffusion while maximizing dopant activation we find that some of the advantages offered by fast ramp-up rates can be duplicated via modification of the implantation parameters. A survey of spike-anneal daa from different sources supports this point.

Ion Implantation and Rapid Thermal Annealing in Synergy for Shallow Junction Formation

Ion implantation in semiconductor device fabrication followed by Rapid Thermal Annealing (RTA) is a useful and essential combination for creating shallow junctions in advanced silicon device technology. The electrical activation of the implanted impurities is an important issue for controlled shallow junction formation in the present ULSI-technology because high electrical activity is needed to assure low contact resistance. The low thermal budget processing of RTA can achieve up to the desired 100% electrical dopant activation with limited diffusion. Transient diffusion related to the type of damage cannot be excluded and has to be reduced by specially chosen implantation conditions. On the other hand, the strong sensitivity of sheet resistance as a function of annealing temperature in the partially activated range helps to optimize and to control the heating uniformity and the repeatability of the RTA equipment. Furthermore specially selected implant conditions for wafers can be used for different process monitors. This flexibility of RTA in combination with ion implantation is illustrated using several ion species and various implant conditions processed in different isochronal or isothermal annealing experiments.