Stress engineering of thin titanium nitride (TiN) films is of considerable importance to the memory industry, where these thin films are free to deform and need to be structurally robust to the deposition of overlying films and processing steps that are a part of the fabrication flow. TiN films in the thickness range of 50 to 100 Å are deposited at 425 °C using atomic layer deposition and are tensile in nature. The as-deposited films are partially surface oxidized due to exposure to atmosphere. The films are subsequently oxidized in an ozone/oxygen ambient at temperatures lower than 275 °C to form a surface oxide layer comprising of titanium dioxide (TiO2) and titanium oxynitride (TiOxNy). Volumetric expansion associated with oxide formation is found to induce compressive stress in the film, while oxidation had the undesirable effect of increasing film resistivity. A dilute hydrofluoric acid solution is used to etch the surface TiO2 layer, while a thin TiOxNy layer remains intact on the film surface. The removal of surface TiO2 results in restoring the resistivity of the films to values comparable to that of as-deposited TiN, while maintaining the compressive stress induced by film oxidation. X-ray photoelectron spectroscopy shows that the processing scheme results in increasing the amount of TiOxNy in the near-surface region of the films. The authors postulate that the higher molar volume TiOxNy layer exerts a compressive force on the underlying TiN film, and prevents a full relaxation of the films to their original tensile stress state. Further, the authors show that by controlling the oxidation conditions, it is possible to modulate the film stress in the range of −750 to +750 MPa. The processing scheme thus allows for stress engineering of thin TiN films at processing temperatures lower than 275 °C.

High velocity aerosol cleaning using ultrapure water or dilute aqueous solutions (e.g. dilute ammonia) is common in semiconductor IC fabrication [1]. This process combines droplet impact forces with continuous liquid flow for improved cleaning efficiency of sub-100nm particles. As with any physically enhanced cleaning process, improved particle removal can be accompanied by increased substrate damage, especially to smaller (<80nm) features [2]. Solvents such as N-methylpyrrolidone (NMP) and tetrahydrofurfuryl alcohol (THFA) are used for resist strip applications [3]. It is possible, and sometimes useful, to deliver these solvents through the same spray nozzle normally used for aqueous spray cleaning. In this presentation we explore the particle removal and substrate damage performance of 2-ethoxyethanol (EGEE), NMP and THFA as used in a conventional aerosol spray cleaning system

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