Fon-Shan Huang

Low-temperature method for enhancing sputter-deposited HfO2 films with complete oxidization

A low-temperature method, supercritical CO2 fluid (SCF) technology, is proposed to improve the dielectric properties of ultrathin hafnium oxide (HfO2) film at 150°C without significant formation of parasitic oxide at the interface between HfO2 and Si substrate. In this research, the HfO2 films were deposited by dc sputter at room temperature and post-treated by SCF which is mixed with 5vol% propyl alcohol and 5vol% H2O. From high-resolution transmission electron microscopy image, the interfacial oxide of SCF-treated HfO2 film is only 5A thick. Additionally, the enhancements in the qualities of sputter-deposited HfO2 film after SCF process are exhibited by x-ray photoelectron spectroscopy and capacitance-voltage (C-V) measurement.

Thermal stability study of TiN/TiSi2 diffusion barrier between Cu and n+Si

The failure mechanism of the TiN/TiSi2 bilayers as diffusion barriers between Cu and n+Si was investigated. The TiN/TiSi2 bilayers were formed by either annealing Ti (50 nm)/n+Si via various rapid thermal processes or reactively sputtering TiN (50 nm) on TiSi2. The degradation study of the Cu/TiN/TiSi2/n+Si contact system was undertaken by scanning electron microscopy, cross‐section transmission electron microscopy (XTEM), secondary‐ion‐mass spectrometry (SIMS), and diode leakage current and contact resistance measurements. Leakage current measurements indicated no deterioration of n+‐p diode junctions up to 475 °C for 30 min in a N2 ambient. For the sintering temperature at 500 °C, the leakage current increased abruptly and SIMS profiles revealed a large amount of Cu atoms diffusing into the junctions of n+‐p diodes. XTEM showed that the small pyramidal‐shaped Cu3Si crystallite (with a size 0.25 μm) precipitated in the n+Si substrate. The formation of Cu3Si increased the occupied volume, then generated t...

A low temperature fabrication of HfO2 films with supercritical CO2 fluid treatment

To improve the dielectric properties of sputter-deposited hafnium oxide (HfO2) films, the supercritical CO2 (SCCO2) fluid technology is introduced as a low temperature treatment. The ultrathin HfO2 films were deposited on p-type (100) silicon wafer by dc sputtering at room temperature and subsequently treated with SCCO2 fluids at 150°C to diminish the traps in the HfO2 films. After SCCO2 treatment, the interfacial parasitic oxide between the Si substrate and HfO2 layer is only about 5A, and the oxygen content of the HfO2 films apparently increased. From current-voltage (I-V) and capacitance-voltage (C-V) measurements, the leakage current density of the SCCO2-treated HfO2 films is repressed from 10−2to10−7A∕cm2 at electric field=3MV∕cm due to the reduction of traps in the HfO2 films. The equivalent oxide thickness also obviously decreased. Besides, the efficiency of terminating traps is relative to the pressure of the SCCO2 fluids.

The Improvement of High-

The impact of the Si cap/SiGe layer on the Hf-based high-<i>k</i> /metal gate SiGe channel pMOSFET performance and reliability has been investigated. We proposed an optimized strain SiGe channel with a Si cap layer to overcome the Ge diffusion and confine the channel carriers in the strained SiGe layer without the formation of a significant parasitic channel at the interface. With this optimized Si/SiGe stack channel, a high-performance Hf-based high-<i>k</i>/metal gate SiGe pMOSFET can be obtained with an appropriate <i>V</i>_TH (~0.3 V), low <i>C</i> -<i>V</i> hysteresis ( <; 5 mV), and better I_ON - I_OFF , <i>V</i>_TH rolloff, and <i>V</i>_TH stability. By the way, the related interface trap density in the high-<i>k</i> gate stack layer can also be reduced, thus improving the devices NBTI and HCI stressing-induced reliability.

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Abstract The physical properties and thermal stability of surface modified methylsilsesquioxane (MSQ) were studied. Various post-treatments, such as thermal oxygen, thermal N 2 O and oxygen plasma, were adopted on the cured MSQ film as the surface-modification process. The Cu/TaN/MSQ/Si metal-insulation-semiconductor capacitors with various surface modified MSQ films were prepared to measure the dielectric constant, capacitance–voltage and current–voltage characteristics. X-Ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were performed in order to understand the chemical composition of the modified film. From the above measurements, we find the best surface treatment condition for MSQ in Cu metallization.

/Metal Gate pMOSFET Performance and Reliability Using Optimized Si Cap/SiGe Channel Structure

Institute of Electronics Engineering, National Tsing Hua University, HsinChu 300, Taiwan Department of Physics and Institute of Electro-Optical Engineering, Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Kaohsiung 804, Taiwan Department of Photonics and Display Institute, National Chiao Tung University, HsinChu 300, Taiwan Industrial Technology Research Institute, Energy and Environment Research Laboratories, HsinChu 300, Taiwan

Surface modification on low dielectric constant material-methylsilsesquioxane

This paper presents the fabrication and characterization of a three-dimensional (3D) thermopile; consists of 71 Cu–Ni series-connected thermocouples on polyimide (PI) flexible substrate. Using wet etching to etch through 25 µm PI, the cold and hot junctions of thermocouples are formed on the top and bottom surfaces of PI substrate. This 3D layout design differentiates its innovative uniqueness from the traditional 2D planar thermopiles that have both hot and cold junctions on the same plane. The experimental studies on the PI etching with respect to the concentrations of KOH and C2H7NO in the etching solution conclude that the optimal composition of the etchant is 7–9 M KOH with 2–4 M C2H7NO and etched at 80 °C. A measured sensitivity of 0.44 mV/K is realized in the fabricated device. The temperatures measured by the 3D thermopile are very close to those obtained with a digital thermometer, demonstrating that 3D flexible thermopiles has great potential to provide low cost thermal sensor.

Application of Supercritical CO2 Fluid for Dielectric Improvement of SiO x Film

In this letter, we investigate the effects of oxide traps induced by various silicon-on-insulator (SOI) thicknesses (<i>T</i> _SOI) on the performance and reliability of a strained SOI MOSFET with SiN-capped contact etch stop layer (CESL). Compared to the thicker <i>T</i> _SOI device, the thinner <i>T</i> _SOI device with high-strain CESL possesses a higher interface trap (<i>N</i> _it) density, leading to degradation in the device performance. On the other hand, however, the thicker <i>T</i> _SOI device reveals inferior gate oxide reliability. From low-frequency noise analysis, we found that thicker <i>T</i> _SOI has a higher bulk oxide trap (<i>N</i> _BOT) density, which is induced by larger strain in the gate oxide film and is mainly responsible for the inferior TDDB reliability. Presumably, the gate oxide film is bended up and down for the p- and nMOSFETs, respectively, by the net stress in thicker <i>T</i> _SOI devices in this strain technology.

Fabrication and Characterization of a Three-Dimensional Flexible Thermopile

In this work, the supercritical CO2 fluid mixed with cosolvents is introduced to terminate the traps in electron-gun (e-gun) evaporation deposited silicon oxide (SiOx) film at 150°C. After the proposed treatment, the SiOx film exhibits a lower leakage current and a resistive switching behavior that is controllable by applying proper voltage bias. The change in resistance is over 102 times and the retention time attains to 2×103s. It is also discovered that the resistive switching behavior seemingly relates to the amount of traps.

The Impact of Oxide Traps Induced by SOI Thickness on Reliability of Fully Silicide Metal-Gate Strained SOI MOSFET

Ultrasonic measurements are presented providing direct measurement of the critical exponent β for a spin glass. Sound velocity measurements were made on Cu0.95Mn0.05 and Cu0.976Mn0.024 single crystals which exhibited the characteristic spin glass cusp in low‐field ac susceptibility. A sound velocity anomaly was observed in the vicinity of the susceptibility peak temperature. We attribute this anomaly to critical fluctuations. Using perturbation theory we show that for a spin glass such as CuMn, the critical part of sound velocity is related to that of the Edwards–Anderson spin glass order parameter q. We are able to determine the critical exponent β associated with this order parameter by fitting the theory to the measured critical change in sound velocity in CuMn samples. By combining our values of β with the values of α′ associated with the critical change in specific heat below the spin glass transition temperature, and Suzuki’s scaling laws,we find the values of exponent γ, αs, and γs, associated with...