A technique for measuring stress (positive and negative) with a lateral spatial extent of approximately 2 pm is introduced. The technique, implemented using a Raman microprobe, is demonstrated with measurements of. the frequency shift of the sharp, R-luminescence lines (2A and E to 4A2 radiative transitions) in, and around, a hardness indentation in a 0.06-wt%-chromium doped sapphire. From the observed frequency shifts the stresses in regions sampled in the hardness impression, in the complex stress field surrounding it, and at the tip of a crack are measured. [

The integration of low- and ultralow-k SiCOH dielectrics in the interconnect structures of very large scale integrated chips involves complex stacks with multiple interfaces. Successful fabrication of reliable chips requires strong adhesion between the different layers of the stacks. A critical interface in the dielectric stack is the interface between the SiCNH diffusion cap and the SiCOH inter- and intralevel dielectrics (ILDs). It was observed that, due to the original deposition conditions, the interface layer was weakened both by a low adhesion strength between SiCNH and SiCOH and by the formation of an initial layer of SiCOH with reduced cohesive strength. The manufacturing process has been modified to engineer this interface and obtain interfacial strengths close to the cohesive strengths of the bulk ILDs. This paper discusses the causes for the original low interfacial strength and presents an approach for enhancing it by engineering the interface to the cap for both the dense SiCOH and porous SiCOH ILDs.

The scaling limit of plasma enhanced chemical vapor deposited (PECVD) ultrathin(5-35 nm) silicon carbon nitride (SiCNH) dielectric as an oxidation and Cu diffusion barrier for damascene process is explored. The SiCNH cap's electrical properties, oxidation barrier performance, and the compositional depth profile analysis results showed that the scaling of the SiCNH cap is limited to 25 nm thickness. Without additional changes in current optimal SiCNH cap, 25 nm is the minimum required thickness for a reliable SiCNH cap in sub-30 nm Cu BEOL devices.

The resistance to plasma-induced damage of various nanoporous, ultra low-κ porous SiCOH films used as interconnect dielectric materials in integrated circuits was studied. These films are susceptible to damage by plasma processes used during nanofabrication. The dielectric constants and chemical compositions of four dielectric films were correlated with measured amounts of plasma damage. Films deposited with higher carbon content in the form of Si–CH3 and Si(CH3)2 bonding exhibited less plasma damage than similar films with lower carbon content.

Various methods of generating high stress in thin plasma enhanced chemical vapor deposition (PECVD) silicon nitride (SiN) films are reported. Besides the mainstream variation of plasma power and other process parameters, novel techniques such as creation of high density layers in multilayer PECVD structures or exposure of SiN films to ultraviolet radiation are shown to increase intrinsic film stress. Thin PECVD SiN films have been analyzed by a variety of analytical techniques including Fourier transform infrared spectroscopy, x-ray reflectivity (XRR), time of flight secondary ion mass spectrometry, and transmission electron microscopy to collect data on bonding, density, chemical composition, and film thickness. The level of bonded hydrogen as well as film density has been found to correlate with film stress. Creation of multilayer structures and high density layers help to build up more stress compared to a standard single layer film deposition. Both the density and number of layers in a film, characterized by XRR, affect the stress. Higher density layers affect diffusion profiles and show impurity oscillations corresponding to a multilayer film structure. Ultraviolet cure allows the film to achieve higher level of tensile stress at relatively low temperatures (400–500°C), comparable to the result of film high temperature annealing.