[en] In this paper, a study on atomic layer deposited (HfO₂)_x(Al₂O₃)_1-x is reported, including the band alignment of (HfO₂)_x(Al₂O₃)_1-x to (100)Si substrate and thermal stability of (HfO₂)_x(Al₂O₃)_1-x. X-ray photoelectron spectroscopy (XPS) shows that the valence band spectra and O1s energy loss spectra change continuously with the variation of Hf (Al) composition in (HfO₂)_x(Al₂O₃)_1-x. The energy gap of (HfO₂)_x(Al₂O₃)_1-x, the valence band offset and the conduction band offset between (HfO₂)_x(Al₂O₃)_1-x and the Si substrate as functions of x are obtained based on the XPS results. The thermal stability of Hf aluminates and its impact on oxygen diffusivity through Hf aluminates are also studied by TEM and XPS. Our results demonstrate that both the thermal stability and the resistance to oxygen diffusion of HfO₂ are improved by adding Al to form Hf aluminates

[en] The effect of scaling down gate oxide thickness on radiation induced damage in MOS capacitors with sub-10nm gate oxides is reported. The trend of reduction in radiation induced positive charge and interface state generation is observed to continue for these ultrathin gate oxides. Results show that neutral trap generation due to radiation exposure is negligible in sub-10nm gate oxides. (Author)

[en] Radiation hardness of furnace N₂O-nitrided gate oxides was investigated for both n- and p-channel MOSFET's by exposing devices in an X-ray radiation system. An enhanced degradation was observed in both control and N₂O-nitrided MOSFET's with reduction in the channel length. Compared to MOSFET's with control oxides, N₂O-nitrided MOSFET's show an enhanced radiation hardness against positive charge buildup and interface state generation. The authors also studied channel hot-carrier effects on the irradiated devices with subsequent low-temperature forming gas annealing. Results show that N₂O-nitrided oxides have a greatly enhanced resistance against radiation-induced neutral electron trap generation

[en] In this letter, the radiation-induced interface state generation ΔD_it in MOS devices with reoxidised nitrided gate oxides has been studied. The reoxidised nitrided oxides were fabricated by rapid thermal reoxidation (RTO) of rapidly thermal nitrided (RTN) SiO₂. The devices were irradiated by exposure to X-rays at doses of 0.5-5.0 Mrad (Si). It is found that the RTO process improves the radiation hardness of RTN oxides in terms of interface state generation. The enhanced interface ''hardness'' of reoxidised nitrided oxides is attributed to the strainless interfacial oxide regrowth or reduction of hydrogen concentration during RTO of RTN oxides. (author)

[en] The radiation hardness of MOS devices with ultrathin nitrided oxides (∼ 100 A) prepared by rapid thermal nitridation (RTN) of thin oxides has been studied. The radiation was performed by exposing devices under X-rays of 50 keV to a dose of 0.5 Mrad(Si). Compared with conventional thermal oxides, the RTN oxide devices exhibit a much smaller increase in both the fixed charge N_f and the interface state D_it densities. In addition, it is found that higher RTN temperature and/or longer durations produce smaller ΔN_f and ΔD_it. (author)

[en] Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak of precipitated dopants produced during high dose implantation

[en] Purpose: To prospectively study the effects of loco-regional radiotherapy in women with breast cancer. Methods and Materials: Thirty consecutive patients with breast resection underwent clinical, lung function, radiographic, and thoracic high-resolution computed tomography evaluation before and at 1, 3, 6, and 12 months after adjuvant radiotherapy. Chemotherapy was also administered to 15 patients. Results: Nineteen patients reported mild respiratory symptoms at 1 month, which resolved completely at 6 months after radiotherapy. Opacities were present on 80% of chest radiographs and in all patients on high-resolution computed tomography by 3 months. These opacities became compact and persisted on high-resolution computed tomography at 12 months. Lung function indices, including FEV₁, FVC, TLC, and DLCO, progressively declined after radiotherapy, and was irreversible at 12 months (p<0.05). Patients who received chemotherapy did not have significantly different lung function indices compared with their counterparts at all time points (p>0.05). Conclusions: Our results have shown that adjuvant loco-regional radiotherapy, a common practice in breast cancer treatment, is associated with irreversible reduction in lung function parameters. These changes are accompanied by radiological evidence of persistent lung injury. Further studies should be performed to evaluate the incidence and long-term pulmonary sequelae of current treatment for breast cancer

[en] Silicon epitaxy plays an important role in improving the performance and reliability of semiconductor devices. The continuous scale-down in device feature size demands a low thermal budget epitaxial technique to maintain the structural integrity of processed devices. In this paper, rapid thermal processing chemical vapor deposition (RTP-CVD) has been used to deposit high quality, thin silicon epitaxial films with superior thickness control. Parameters affecting the quality and rate of epitaxial growth are discussed

[en] We report a low-temperature (350 deg. C) anodic bonding followed by grind/etch-back method for a 200 mm wafer-scale epitaxial transfer of ultrathin (1.9 kA) single crystalline Si on Pyrex glass. Standard back-end-of-line 3 kA SiN/3 kA undoped silicon glass passivating films were used as the buffer layers between the silicon-on-insulator wafer and the glass wafer. The quality and strain-free state of the transferred transparent Si film to glass was characterized by cross-sectional transmission electron microscopy, x-ray diffraction (XRD), and high-resolution XRD. Complete removal of the bulk Si after bonding was ascertained by Auger electron spectroscopy spectra and depth profiling. Strong adhesion between the transferred film and the glass wafer was verified by standard tape adhesion tests. This process will pave the way for future generations of Si-based microelectronics including bioelectronics

[en] A novel technique for the fabrication of shallow, silicided p/sup +/-n junctions with excellent electrical characteristics has been developed. The technique utilizes the ion implantation of dopants into silicide layers formed by ion-beam mixing with Si ions and low temperature annealing, and the subsequent drive-in of implanted dopants into the Si substrates to form shallow junctions. This technique can be easily applied to the fabrication of MOSFETs in a self-aligned fashion, and can have a significant impact on CMOS VLSI technology