Stress Analyses during Chemical Mechanical Planarization Processing with Cu/Porous Low-k Structures of LSI Devices

Abstract

A scintillation counter telescope of aperture 0.47 m2 sr and incorporating layers of crossed neon flash tubes has been used to search for relativistic ei3 and 2e/3 quarks in the near-vertical cosmic radiation at sea level. Events were selected where the scintillator pulse heights were as expected for quarks and the corresponding flash tube records were studied.No events satisfied all the rigorous acceptance criteria and only upper limits can be given for the quark flux. These are, at the 90% confidence limits: < 1.15 x l 0 -l 0 c m -2 s -I s r -l for relativistic e/3 quarks and < 8.0 x c m -z s-I s r -l for relativistic 2e/3 quarks.

Shear Stress Analyses in Chemical Mechanical Planarization with Cu/Porous Low-k Structure

“…We reported that a normal stress field exists at the surface of Cu/porous low-k structures assessed by finite element method (FEM) during CMP and that high normal stress fields induce defects such as stress corrosion cracking (SCC). [5][6][7] We also confirmed that normal stress particularly concentrated at the edges of a Cu wiring depends on interlayer dielectric (ILD) modulus, CMP steps, and CMP downward pressure. 5) However, other stress fields, especially shear stress distribution, is not yet well understood owing to the very few studies 9) of them, although shear stress may induce the delamination of low-k films during CMP.…”

“…[5][6][7] We also confirmed that normal stress particularly concentrated at the edges of a Cu wiring depends on interlayer dielectric (ILD) modulus, CMP steps, and CMP downward pressure. 5) However, other stress fields, especially shear stress distribution, is not yet well understood owing to the very few studies 9) of them, although shear stress may induce the delamination of low-k films during CMP. 4) In this study, we determine the relation between the shear stress distribution in the depth direction during CMP and the ILD structure as assessed by FEM, and provided new suggestions from our results.…”

“…1) However, the extremely low Young's moduli of these materials result in a large number of defects such as scratches, delamination, and corrosions. 2,3) The reported solutions to these problems are as follows; lower downward pressure, 4,5) lower friction, 8) and control the real contact area between the surface of a device and the pad/abrasives 5,8) in chemical mechanical planarization (CMP). We reported that a normal stress field exists at the surface of Cu/porous low-k structures assessed by finite element method (FEM) during CMP and that high normal stress fields induce defects such as stress corrosion cracking (SCC).…”

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

“…Stress engineering related to the frontend process as well as the backend process of LSI is required [1][2][3][4][5][6][7]. As for shallow trench isolation (STI) structures, it was reported that a high stress field in the structure causes a variation in electrical characteristics [8].…”

Evaluation of Dielectric Constant through Direct Chemical Mechanical Planarization of Porous Low-k Film

“…3) The effects of water absorption on the electronic characteristics of LSI devices are reported. 18) In CMP and post-CMP cleaning, an increase in k-value is also a major concern because not only water but also several types of organic components such as surfactants [19][20][21][22][23] are used. Actually, up to 50% increase in kvalue during CMP of porous low-k films is reported.…”