Defect Capture Rate Research Articles

RIE-Induced VIA Defect Inspection Using In-line Voltage Contrast Technique – 0.18 µm Technology

Optical inspection is used in large-scale manufacturing processes to identify the pattern defect. However, the capture rate of killer defects is low due to the resolution limit of optical inspection. The Voltage Contrast (VC) technique of Scanning Electron Microscope (SEM) was developed to detect killer defects. The VC electron beam inspection is a widely used method in the IC manufacturing industry for the monitoring and characterisation of electrical defects at an early stage. The major drawback of E-Beam inspection is low throughput. To enhance the chip yield, some defects should be detected and reduced in the early stage of fabrication. Herein, we present the Back End of Line (BEOL) fabrication with 0.18 µm process technology and the application of VC methodology to inspect electrical defects. The defects mostly occur due to marginal process window, which affects the etching and lithography process. These effects lead to metal shorts and partial etch of interconnect producing open VIA12. Using inline VC-SEM the invisible defects can be detected at an early stage and chip yield can be further improved.

Defect capturing and charging dynamics and their effects on magneto-transport of electrons in quantum wells

The calculated defect corrections to the polarization and dielectric functions for Bloch electrons in quantum wells are presented. These results were employed to derive the first two moment equations from the Boltzmann transport theory and then applied to explore the role played by defects on the magneto-transport of Bloch electrons. Additionally, we have derived analytically the inverse momentum-relaxation time and mobility tensor for Bloch electrons by making use of the screened defect-corrected polarization function. Based on quantum-statistical theory, we have investigated the defect capture and charging dynamics by employing a parameterized physics-based model for defects to obtain defect wave functions. Both capture and relaxation rates, as well as the density for captured Bloch electrons, were calculated self-consistently as functions of temperature, doping density and chosen defect parameters. By applying the energy-balance equation, the number of occupied energy levels and the chemical potential of defects were determined, with which the transition rate for defect capturing was obtained. By applying these results, the defect energy-relaxation, capture and escape rates, and Bloch-electron chemical potential were calculated self-consistently for a non-canonical subsystem of Bloch electrons. At the same time, the energy- and momentum-relaxation rates of Bloch electrons, as well as the current suppression factor, were also investigated quantitatively. By combining all these results, the temperature dependence of the Hall and longitudinal mobilities was presented for Bloch electrons in either single- or multi-quantum wells.

A comparative study on radiation reliability of composite channel InP high electron mobility transistors* *Project supported by the National Natural Science Foundationof China (Grant No. 11775191), the Natural Science Foundation of Henan Province, China (Grant No. 202300410379), the Promotion Funding for Excellent Young Backbone Teacher of Henan Province, China (Grant No. 2019GGJS017), Key Technologies Research and Development Program of Henan

This paper proposes a reasonable radiation-resistant composite channel structure for InP HEMTs. The simulation results show that the composite channel structure has excellent electrical properties due to increased modulation doping efficiency and carrier confinement. Moreover, the direct current (DC) and radio frequency (RF) characteristics and their reliability between the single channel structure and the composite channel structure after 75-keV proton irradiation are compared in detail. The results show that the composite channel structure has excellent radiation tolerance. Mechanism analysis demonstrates that the composite channel structure weakens the carrier removal effect. This phenomenon can account for the increase of native carrier and the decrease of defect capture rate.

Capture rate of congenital heart defects in the Pediatric Health Information System database.

Congenital heart defects (CHD) are common and are a frequent subject of research using large administrative databases such as the Pediatric Health Information System (PHIS) database. The capture rate of CHD within PHIS, however, has not been described. The PHIS database includes inpatient encounters from over 52 tertiary care pediatric hospitals across the United States. We identified all patients less than 1 year of age with a cardiac defect in PHIS from 2010 to 2014 and compared these results with national prevalence estimates based on the National Birth Defects Prevention Network annual report, which served as the gold standard. The capture rate of CHD in PHIS ranged from 30 to 95% depending on the spectrum of severity and heterogeneity of the cardiac defect. The capture rate was higher for critical CHD (CCHD) at 66%, and all lesions with 70% or greater capture rate (interrupted aortic arch, truncus arteriosus, single ventricle, total anomalous pulmonary venous return, double outlet right ventricle, and hypoplastic left heart syndrome) fell within the CCHD category. Just over half of the predicted CHD patients were identified using the PHIS database. Although there is a high capture rate for CHD that require early hospitalization, there is a low capture rate for defects with a wider spectrum of disease presentation. These attributes of the PHIS database should be used to frame previous and future research using PHIS to study CHD.

A novel approach to quantifying the kinetics of point defect absorption at dislocations

Microstructure evolution under creep loading and/or irradiation is largely affected by the two-way coupling between dislocation induced plasticity and point defect diffusion as mediated by the internal elastic strain field within the medium. The magnitude of this effect has been quantified only in idealized, simplified environments such that estimates of absorption rates of point defects to dislocations ignore the collective effects on capture rates arising from particular distribution of dislocations in a given network, the interaction of point defects with the internal strain, or in many cases both. To quantify these effects, we advance a novel methodology to determine point defect capture rates locally within a spatially resolved finite difference solution to the diffusion problem for arbitrarily directed dislocations and the corresponding strain fields. In addition to examining the effects of these couplings on local and effective absorption rates of dislocation networks, the potential consequences of these interactions on other microstructure evolution phenomena are examined using void swelling under irradiation as an example. Our study indicates that local rates of defect mediated microstructural changes such as cavity growth can vary strongly as a consequence of the arrangement of the dislocation network and the corresponding strain state. The heterogeneous aspects of the resultant defect populations are shown to provide mechanisms for microstructural evolution under irradiation that are not available in the conventional homogeneous theory.

The High Electron Dose of Voltage Contrast Inspection for the Detection of Nickel Silicide Piping Defects

Nickel silicide process is used for the ohmic contact formation, but it could be spiking or piping into the substrate and lead to the device fail by leakage with the high temperature anneal. The piping defect by the nickel silicide process was proposed to be inspected using the electron beam inspection (EBI) at contact tungsten (W) plug CMP. This paper aims at the methodology of piping defect inspection and presents an optimized method to detect true piping defects by high electrons dosage. In this study, The mechanism of the leakage spread effect is described and with a series of experiments during the recipe optimizeation, the electron dosage, landing energy and beam direction were identified to increase the piping defect capture rate.

On the interpretation of positron-annihilation data in powders and fine-grained materials

Monte-Carlo simulations of positron diffusion are carried out for powders consisting of spherical and ellipsoidal particles with and without defects. Following Bergersen et al. [1], elastic positron-phonon interaction is considered to be dominant for scattering processes in positron diffusion. The central question is which fraction of the positrons would be able to reach the particle boundaries. Hence, we calculate the Fraction of Positrons reaching particle Surface (FPS). The presence of defects in the particles can drastically reduce FPS depending on the defect concentration and capture rate. We demonstrate that for small-grained materials the grain surface can influence the lifetime signal significantly.

Calculation of Reverse Annealing in Neutron Damaged p-Type Silicon

A calculation of the reverse annealing process in neutron-burst irradiated p-type silicon at 300°K was performed, utilizing a variation of the equilibrium cluster theory of Gregory. Material conditions which were considered included 1, 10, and 100 ?-cm material with an injection ratio of 10-6 , and 1 ?-cm material with injection ratios of 10-7 and 10-8. This calculation demonstrated the relationship between the peak and time of occurrence of the damage constant versus time curve and the material resistivity and injection level. It was also shown that the reverse annealing rate depends upon the capture rate of defects in the cluster, rather than the rate of transport of defects from the depletion region to the cluster. These carrier capture rates were such that the forward annealing process usually began before the clusters reached charge saturation. Finally, it was concluded that an injected minority carrier pulse lasting less than 5×10-6 sec after burst will not appreciably affect the reverse annealing process.