Defect density measurement

Increase in the concentration of thiourea clearly leads to an increase in deposition rate. Additionally, it has been seen that the defect density (measured from TEM micrographs as structural defects such as stacking faults) decreased greatly with... 

In Fig. 2, top-down SEM images of photoresist structures of variable line width are shown after cationic surfactant rinse (upper row) and after conventional rinse without surfactants (lower row). The improvement is evident While without surfactant rinse the lines start to collapse at a width between 65 and 70 nm they collapse after surfactant rinse below 60 nm. Defect density measurements, too, showed a significant reduction of defects due to pattern collapse by surfactant rinse [21],... 

Fig. 8.20. The dependence of the band tail luminescence intensity on the defect density measured by ESR. The solid lines are fits to Eq. (8.52) (Street et al. 1978).

Uniformity characterization of luminescent materials (e.g., mapping of defects and measurement of their densities, and impurity segregation studies)... 

Little information is available on homogeneity ranges and defect structures in the dodecaborides. The only variation from stoichiometry in these borides is for YB,2i the limiting phase determined by density measurements is Yq92B,2. This result can be attributed to the size of Y which is the maximum for metals that form the dodecaborides. Attempts to prepare DyB,2 with a nonstoichiometric composition are conclusive. ... 

In the low-energy range a depends on the defect density, doping level, and details of the preparation process. Sensitive subbandgap spectroscopy is used to measure a and relate it to the defect density in the material [78, 79]. 

As the thickness t (measured in micrometers) grows smaller, the defect density grows larger. The number of defects per square centimeter of resist is given by... 

Contamination of silicon wafers by heavy metals is a major cause of low yields in the manufacture of electronic devices. Concentrations in the order of 1011 cm-3 [Ha2] are sufficient to affect the device performance, because impurity atoms constitute recombination centers for minority carriers and thereby reduce their lifetime [Scl7]. In addition, precipitates caused by contaminants may affect gate oxide quality. Note that a contamination of 1011 cnT3 corresponds to a pinhead of iron (1 mm3) dissolved in a swimming pool of silicon (850 m3). Such minute contamination levels are far below the detection limit of the standard analytical techniques used in chemistry. The best way to detect such traces of contaminants is to measure the induced change in electronic properties itself, such as the oxide defect density or the minority carrier lifetime, respectively diffusion length. 

It is usually assumed that the dominant defect species responsible for nonstoichiometry is constituted by oxygen vacancies (rather than metal interstitials). This assumption can be justified on the basis of X-ray and neutron diffraction and density measurements . ... 

In summary, non-stoichiometric compounds are found to exist over a range of composition, and throughout that range the unit cell length varies smoothly with no change of symmetry. It is possible to determine whether the non-stoichiometry is accommodated by vacancy or interstitial defects using density measurements. 

Figure 11. The measured defect density profile in 3 Q-cm TiOt sample aged under constant voltage (+5 V)for 30 h. The data is normalized to the bulk density.

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