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The presence of silicon oxyphosphorus bonds in the heavily phosphorus (P)-doped n+-type polycrystalline silicon film (n+-poly Si) of TOPCon solar cell has been mainly revealed through a depth-profile X-ray photoelectron spectroscopy (XPS) characterization of chemical components. X-ray diffraction (XRD) pattern is applied to the verification of recrystallized phases in the n+-poly Si film, while high-resolution transmission electron microscopy (HR-TEM) with energy dispersive X-ray (EDX) pattern is used for distinguishing the crystallinity and the elemental segregation. The test sample is of a typical rear passivation contact stacks of c-Si/SiO x /n+-poly Si/SiO 2 , in which the n+-poly Si layer is heavily phosphorus-doped by ion implantation of as-deposited intrinsic thin film through low-pressure chemical vapor deposition (LPCVD) and recrystallization at 900 °C afterward. In the whole n+-poly Si layer, XPS P 2p electronic states at 129.8, 133.4 and 136.8 eV have been detected and assigned to be Si–P (or P–P), O–P and P–O–P bonds, respectively. In addition, the thermodynamic functions, such as the Gibbs free energy and mole formation energy of likely chemical bonds under the lowest energy as well as temperature-composition fraction (T-CF) phase diagram, are also implemented in the verification of the derivatives of phosphorus oxides. • Disclosing of phosphorus oxides or P–O bonds present in n+-poly Si film of TOPCon device. • XPS with depth-profile of chemical components has been applied to the qualitative determination of oxyphosphorus bonds. • The localized segregation of phosphorus and oxygen within n+-poly Si film has been observed through EDX for textured surface. • The reasonable verification of oxyphosphide in n+-poly Si film was fulfilled by thermodynamic analysis. [ABSTRACT FROM AUTHOR]

Abstract: As the device shrunk to100 nm, the CVD TiN barrier filling would be limited by the process window of contact for both step coverage and plasma treatment. This limitation not only affects the step coverage capability but also poses a challenge to the treatment of the organic film with the small contact hole. In this study, we investigated whether the plasma treatment of the TiN film barrier influences the subsequent tungsten deposition and causes the change of the gapfilling behavior. After the different RF plasma treatment, we found that the resistivity and impurity level of the thin TiN film can influence not only the contact resistance and uniformity, but also the product yield. The over-treatment contacts were found with porous voids in the poor tungsten deposition during the contact filling even after CMP polishing. The resistances of under-treatment contacts would be determined by the impurity level of TiN films. Hence, the optimized TiN deposition and treatment would be critical to the contact resistance and yield performance. [Copyright &y& Elsevier]

Abstract: Resistance of low dielectric constant (low-k) dielectrics, deposited using Diethoxymethylsilane (DEMS) precursor and helium (He) carrier gas with or without oxygen (O2) reaction gas, against heat, moisture stress and chemical treatment is clarified. The low dielectric constant organosilicate glass (OSG) films deposited using DEMS and O2 is shown to be the most reliable: the dielectric constant are stable even after a heating test at 700 °C and a pressure cooker test (PCT) for 168 h. This stability is high enough to ensure the low-k properties throughout fabricating multilevel interconnects and long-term reliability after the fabrication. This is due to the stability of Si–CH3 bonds and more Si–C–Si– bonds, which has high degree of cross-linking. However, the degradation of the dielectric constant occurs after O2 plasma ashing process. The nitrogen plasma treatment is proposed to prevent the damage from O2 attack in the low-k films deposited using DEMS precursor. [Copyright &y& Elsevier]

Abstract: Plasma chamber dry clean after chemical vapor deposition (CVD) was widely used in the plasma enhanced CVD processes. The effects of the plasma clean periodicity on the deposited film qualities were explored in this research. The variations of the film qualities of high-density plasma phosphosilicate glass (HDP-PSG) were found for consecutive film deposition. The comparisons in the film qualities such as phosphorous concentration, stress, thickness and wet etch rate for successively depositing wafers after plasma chamber dry clean were studied. The phosphorous concentrations were measured using X-ray fluorescence (XRF) method. The consecutively depositing wafers exhibited comparable phosphorous concentrations from the XRF results. The stress of the first three wafers had 10% difference. The first wafer had the most compressive stress. The film thickness of the first wafer was 30–40 nm thicker than that of the third wafer. The film wet etch rate also showed a decreasing trend. The first wafer had 10% higher wet etch rate than the third wafer. The secondary ion mass spectrometry (SIMS) analysis displayed that the first wafer had more uniform phosphorous distribution. The different phosphorus depth profile generated the different wet etch rate performance for the consecutive deposition wafers. These differences in the film qualities were caused by the chamber out-gassing. The residual gas analysis (RGA) was used to monitor the chamber out-gassing. The oxygen and moisture from the chamber out-gassing impacted the HDP-PSG film qualities for no in situ plasma chamber clean. [Copyright &y& Elsevier]

Abstract: For a low dielectric constant inter-metal dielectric application, the low-k SiCOH film with a dielectric constant of 2.8–3.2 has been deposited by plasma-enhanced chemical vapor deposition (PE-CVD) with trimethylsilane (3MS), oxygen, and the carrier gas. In this work, we present the effects of the carrier gas on the characterizations of the low-k films, including reaction mechanism, the deposition rate, and the mechanical and electrical properties. According to the experimental results, the low-k film in Ar carrier gas exhibits the improvement in deposition rate, nonuniformity, leakage current, and hardness. In addition, the dielectric constant of the deposited low-k film is slightly sacrificed due to the decrease of micropores in the deposited films. [Copyright &y& Elsevier]

Recently, fluorosilicate glass (FSG) has received much attention for application in microelectronics manufacturing due to its low dielectric constant and stable gap-filling ability. Although FSG films have been demonstrated as potential inter metal dielectrics (IMD) for sub-micron devices, integrating a stack of two fluorine doped silicon oxide film deposited on a high-density plasma chemical vapor deposition (HDP-CVD) system for gap filling and a plasma-enhanced chemical vapor deposition (PECVD) system for throughput has not been fully investigated. In this research, an excellent and exceptionally stable process was demonstrated for a stack of HDP-CVD FSG and PECVD FSG layers. Cracks that result from multi-level metal technology were eliminated when higher compressive stress PECVD FSG film was implemented as a capping layer. An 11% capacitance reduction was achieved when comparing a stack of FSG films to undoped silicon oxide. No problem occurred for photo, via etching and chemical mechanical polishing of FSG film. The FSG layer stack’s via resistance (Rc_Via) as well as a full HDP-FSG scheme is comparable. These results are very promising for the integration of FSG films as inter metal dielectric for devices. [Copyright &y& Elsevier]

Abstract: SiCf/SiC composite is considered as one of the most promising structural material candidates for fusion reactors. Its corrosion behavior in liquid LiPb at high temperature needs to be investigated in details. A capsule named DRAGON-ST was designed and built for static corrosion experiment at 700°C as a first step in order to evaluate the corrosion behavior of homebred SiCf/SiC composite with LiPb, it was characterized by weight change and observation of corroded surfaces. The results after 500h experiment showed that the 3D SiCf/SiC composite with CVD (chemical vapor deposition)–SiC coating was stable in the liquid LiPb, most area of the composites surface and the matrix remained well. Further study needs to be carried out to evaluate the compatibility of SiCf/SiC composites with LiPb completely. [Copyright &y& Elsevier]