Shigeru Kakinuma

Nanometer‐Scale Stress Field Evaluation of Cu/ILD Structure by Cathodoluminescence Spectroscopy

Engineering of the residual stress fields related to the backend process of LSI devices with Cu interconnects is required together with the adoption of low‐k materials that have quite low Youngs modulus. We measured the nano‐scale residual stresses stored within interlayer dielectric (ILD) films according to a cathodoluminescence (CL) piezo‐spectroscopic technique. The SiO2 film (k = 4.1) produced a sharp and stable spectrum, which well suited for the analysis of stress distribution on the surface. We confirmed that stresses in ILD could be successfully detected with less than 50 nm spatial resolution and that a higher chemical mechanical polishing (CMP) downward pressure led to a shift toward the tensile side of the residual stress field stored in the ILD film. We also carried out line‐scan analyses of a cross section as well as a surface of the sample. Furthermore, we performed thermal stress analyses by FEM and made a comparison with the CL results. The tensile stress peak neighboring a Cu line observ...

Helium ion microscope characterization for Cu / low-k interconnects - SE imaging and focused helium ion beam luminescence detection -

Several novel imaging modes of the recently developed helium ion microscope (HIM) 1) were explored that may make the HIM a tool of particular value to Cu / low-k (dielectric constant) interconnect structures. Mechanism of the “through dielectric” (2) imaging of the Cu interconnects underneath the low-k SiOC film was proposed, and materials contrast in the low-k regions between Cu lines was imaged which might reflect damaged low-k areas. Furthermore possibility of detection of luminescence induced by the focused helium ion beam using the HIM for materials property characterizations was studied for the first time.

Stress Field and Defect Evaluation with Shallow Trench Isolation Structure after Transistor Fabrication Processing by Raman and Cathodoluminescence Spectroscopies

Masako Kodera , Norihiko Tsuchiya , Shigeru Kakinuma , and Nobuyuki Naka 3 1 Center for Semiconductor Research and Development, Toshiba Semiconductor & Storage Products Company, 800, Yamanoisshiki-Cho, Yokkaichi, 512-8550 Japan 2 Analysis Inspectiont and Metrology Engineering Dept., Yokkaichi Operations, Toshiba Semiconductor & Storage Products Company, 3 Horiba, Ltd., * e-mail; masako.kodera@toshiba.co.jp

Cathodoluminescence spectroscopy study for non-destructive stress analysis of thermal silicon-oxide film

In this article, a technique for non-destructive stress analysis of thermal silicon-oxide (SiOx) film using cathodoluminescence (CL) spectroscopy is described. The uniaxial tensile tester which can be used in a scanning electron microscope (SEM) chamber was developed to apply tensile stress to the film specimen. CL spectra of SiOx film were measured under various tensile stresses. The peak position linearly increased at 7.53×10-3 eV/GPa with an increase in tensile stress. The peak intensity and half bandwidth changed with an increase in electron beam (EB) irradiation time period. Using Raman spectroscope and transmission electron microscope (TEM), it was found that EB irradiation produced silicon nanocrystals in SiOx film. The nanocrystals as well as applied stress affected CL spectra.

Effect of CMP downward pressure on nano-scale residual stresses in dielectric films with Cu interconnects assessed by cathodoluminescence spectroscopy

Engineering of the residual stress fields related to the backend process of LSI devices with Cu interconnects is required together with the adoption of low-k materials that have quite low Youngs modulus. We measured the nano-scale residual stresses stored within interlayer dielectric (ILD) films according to a cathodoluminescence piezospectroscopic technique. We confirmed that stresses in ILD could be successfully detected with less than 50 nm resolution and that a higher chemical mechanical polishing (CMP) downward pressure led to a shift toward the tensile side of the residual stress field stored in the ILD film.