Papers by Keyword: Rapid Thermal Annealing (RTA)

Abstract: Cuprous oxide (Cu₂O) has a high optical absorption coefficient and favourable electrical properties, which make Cu₂O thin films attractive for photovoltaic applications. Using reactive radio-frequency magnetron sputtering, high quality Cu₂O thin films with good carrier transport properties were prepared. This paper presents the characteristics of Cu₂O thin films that were sputter deposited on quartz substrates and subjected to post-deposition rapid thermal annealing. The thickness of the thin films and the optical constants were determined by ellipsometry spectroscopy (SE). The optical transmittance increased in lower wavelength region after annealing at 900 ̊C in rapid thermal annealing (RTA). The structural and morphological properties of the Cu₂O thin films were investigated by electronic scanning microscopy (SEM) and atomic force microscopy (AFM), whereas elemental analysis was performed by X-ray fluorescence spectroscopy (XRF). The carrier mobility, carrier density and film resistivity were changed after post-deposition rapid thermal annealing from respectively ~14 cm2/Vs, ~2.3 x 10¹⁵ cm^-3 and ~193 Ωcm for the as-deposited Cu₂O film to ~49 cm2/Vs, ~5.0 x 10¹⁴ cm^-3 and ~218 Ωcm for the annealed Cu₂O film. The investigation suggests that the sputter-deposited Cu₂O thin films have good potential for application as absorber layers in solar cells.

Abstract: Using the radio frequency magnetron sputtering that directly bombardment A1N target under different sputtering-power and total pressure to deposit the A1N thin films. The crystal structure, composition, surface and refractive index of the thin films were studied by XRD, SEM, AFM and elliptical polarization instrument. The results show that the surface and refractive of the thin films strongly depends on the sputtering-power and total pressure,the good uniformity and smoothness is found at 225 W, Ar flow ratio 5.0 L_Ar/sccm, substrate temperature 100°Cand 1.2 Pa. All film thickness are from 60 to 80nm, and the highest N/Al mole ratio reach to 0.83.The crystal structure of the as-deposited thin-films is amorphous，then it transforms from blende structure to wurtzite structure as the rapid thermal annealing(RTA) temperature changes from 600 to 1200°C. The refractive index also increases with the RTA temperature it is increasing significantly from 800 to 1000°C. When the Annealing temperature at 1000°C, we get the best uniformity and smoothness of the surface of the film.

Abstract: AlN dielectric thin films were deposited on N type Si(100) substrate by reactive radio frequency magnetron sputtering that directly bombardment AlN target under different sputtering-power and total pressure. The crystal structure,composition,surface and refractive index of the thin films were studied by XRD, SEM, AFM and elliptical polarization instrument. The results show that the surface and refractive of the thin films strongly depends on the sputtering-power and total pressure,the good uniformity and smoothness is found at 230 W, Ar flow ratio 5.0 LAr/sccm, substrate temperature 100°Cand 1.2 Pa. The crystal structure of the as-deposited thin-films is amorphous，then it transforms from blende structure to wurtzite structure as the rapid thermal annealing(RTA) temperature changes from 600 to 1200°C. The refractive index also increases with the RTA temperature it is increasing significantly from 800 to 1000°C．

Abstract: 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.

Abstract: In this study we use chemical and physical vapor depositions to fabricate amorphous silicon (a-Si) films. We also use traditional rapid thermal annealing (RTA) and advanced microwave annealing (MWA) to activate or crystallize a-Si films and then observe their sheet resistances and crystallization. We discovered, although the cost of films fabricated by electron beam (e-beam) evaporation is relatively lower than by chemical vapor deposition (CVD), the effects of the former method are poorer whether in sheet resistance or film crystallization. In addition, only at the doping layer prepared by CVD can film crystallization degree produced by MWA match RTA.

Abstract: Based on TEOS system and sol-gel process, together with catalysts, Antireflective coating films prepared by sol—gel on glass substrate have been processed by rapid thermal annealing (RTA). the refractive index and thinkness of SiO2 film is exactly controlled. The films are characterized by ellipsometer and SEM respectively. The quantum states in these processions are found and discussed.

Abstract: In this study, a novel nanogap fabrication technique is proposed. The technique is based on electron-beam lithography combined with rapid thermal annealing (RTA) to reduce the self-aligned nanogap on metal layer. The procedure running through systematic experimental design via Taguchi method and considering the critical factors such as metal type, Si thickness, RTA temperature, RTA time and initial nanogap dimension affecting the final nanogap dimensions was optimized. The experiments were conducted using Taguchi method and modified particle swarm optimization for setting the optimal parameters. The experimental results show that the most important factors in nanogap reduction were the metal type and the initial nanogap. The optimal parameter settings were metal type Pt on 50 nm Si/SiO₂, 400°C, 60s and 43nm for initial gap. Experiment results found that the metal type Pt provided larger shrink ratio than that of Ni and nanogap down to 30 nm. It is also noted that the proposed approach was reproducible due to the confirmation experiments SNRs within the 95% confidence interval.

Abstract: In the process of characterizing AlGaN/GaN HEMTs on Si (111), Sapphire, 4H-SiC substrates, various Rapid Thermal Annealing (RTA) conditions for the Ti/Al/Ta/Au ohmic contact process and the resulting surface analysis have been investigated. In order to achieve a low ohmic contact resistance (RC) and a high quality surface morphology, we tested seven steps (800 °C to 920 °C) annealing temperatures and two steps (15, 30 sec) annealing times. According to these annealing temperatures and times, the optimal ohmic resistance of 3.62 × 10^-6 Ohm • cm² on Si(111) substrate, 9.44 × 10^-6 Ohm • cm² on Sapphire substrate and 1.24 × 10^-6 Ohm • cm² on 4H-SiC substrate are obtained at an annealing temperature of 850 °C and an annealing time of 30 sec, 800 °C and an annealing time of 30 sec and 900 °C and an annealing time of 30 sec, respectively. The surface morphologies of the ohmic contact metallization at different annealing temperatures are measured using an Atomic Force Microscope (AFM). AFM morphology Root Mean Square (RMS) level determines the relationship of the annealing temperature and the annealing time for all of the samples. According to these annealing temperatures and times, the optimal ohmic surface RMS roughness of 13.4 nm on Si(111) substrate, 3.8 nm on Sapphire substrate and 2.9 nm on 4H-SiC substrate are obtained at an annealing temperature of 850 °C and an annealing time of 30 sec, 800 °C and an annealing time of 30 sec and 900 °C and an annealing time of 30 sec, respectively.

Abstract: In this article, we have explained quantum state observed in fabricating poly-silicon the thin film and calculated the crystallization procession of rapid thermal annealing as a function of light energy. Equal energy driving principle was presented, it is shown that the change in magnetic frequency leads to the conversion of magnetic field energy to annealing energy.

Abstract: In this work, layer structured silicon suboxide/gold/silicon suboxide (SiOx/Au/SiOx) films were prepared by using plasma enhanced chemical vapor deposition assisted with hot wire evaporation technique. Post rapid thermal annealing (RTA) process was done on the as-prepared films for 100, 500 and 700s at constant temperature of 800oC in vacuum ambient. Effects of RTA process on the structural and morphological properties of films were studied using FE-SEM, depth profiling and XRD measurement. While, surface plasmon resonance (SPR) phenomenon exhibited by Au particles was investigated via the optical absorption spectra. SPR signals can be exhibited by sample annealed for longer time duration. Individual Au islands tend to form the spherical shape as a whole. Diffusion of Au particles towards the surface of SiOx film is temperature dependent and crystallite size of Au enlarges with the rapid thermal annealing time.