Emma Brouk

Organosiloxane based bottom antireflective coating for 193nm lithography

A spin-on sacrificial 193 nm UV absorbing organosiloxane film was developed to facilitate ArF photoresist (PR) patterning. To improve lithographic compatibility with acrylate based photoresists, different performance additives were evaluated as photoresist adhesion promoter. The results suggested that the type and loading of the photoresist adhesion promoter had a large impact on the profile and focus latitude of the patterned photoresist features. An efficient photoresist adhesion promoter candidate was identified, which has minimum impact on other solution and film properties. This work has led to the development of DUO 193 organosiloxane based bottom anti-reflective coating. Application of this film as a blanket level bottom anti-reflective coating or as a fill material for via first trench last (VFTL) dual damascene patterning is possible. The SiO structure intrinsic to this film provides a high degree of plasma etch selectivity to the thin ArF photoresists in use today. Furthermore, an equivalent plasma etch rate between DUO 193 and the low dielectric constant SiOCH films used as the dielectric layer in the backend Cu interconnect structure is possible without compromising the photoresist etch selectivity. Equivalent etch rate is necessary for complete elimination of the “fencing” or “shell” defects found at the base of the etched trench feature located at the perimeter of the top of the via. Advanced ArF PR features of 100 nm in width (and smaller) have been routinely patterned on DUO 193 film. Via fill, plasma etch rate, wet etch rate, ArF PR patterning and shelf life data will be discussed in this presentation.

65.2: Spin-On Polymers for TFT Gate Dielectric Application and Planarization of Stainless Steel

We present spin-on polymer films with significantly improved dielectric properties for TFT gate dielectric applications. Breakdown voltage//leakage current//CV hysteresis are 4.10 MV/cm at 1 μA/cm2//4.9 × 10−8 A/cm2 at 2.5 MV/cm//3.4 V and 4.73 MV/cm//2.6 × 10−8 A/cm2//0.44V at curing temperatures of 250 °C and 425 °C, respectively. In addition, we present our recent results using spin-on dielectrics to planarize and insulate stainless steel substrates for flexible displays and high resolution QVGA mobile displays.

Performance properties in thick film silicate dielectric layers using molecular modeling

Molecular modeling was employed to understand various properties found in thick film dielectric layers derived from solution-based sol-gel formulation in order to aid their development. For instance, for formulations used as planarizing layers, it was discovered that during certain process steps ionic components could be introduced which greatly influences the extent of shrinkage by up to 50%, a phenomenon not normally seen in traditional spin-on glasses (SOG). Thermodynamic calculations showed that specific ionic contaminants contribute to the cure state of the material, potentially depolymerizing the material and promoting the formation of structures that are more easily deformed. Volumetric analysis and compaction modeling demonstrated that the high extent of shrinkage is expected, depending upon the final structure of the silicate. Calculation of the relative modulus of the different suspected structures also showed that depolymerized structures contribute to the ease of compaction.

Spin-on Gate Dielectric Materials for Next Generation Display Systems

We present recent advances on spin-on polymers as gate dielectric for thin film transistors. We have developed film type I with significantly improved dielectric properties. At a curing temperature of 250 °C, the dielectric constant is 3.46, the breakdown voltage is 4.10 MV/cm at 1 μA/cm 2 , the leakage current is 4.9 × 10 −8 A/cm 2 at 2.5 MV/cm, and the CV hysteresis is 3.4 V. At a curing temperature of 425 °C, the dielectric constant, the breakdown voltage, the leakage current, and the CV hysteresis are 3.2, 4.73 MV/cm, 2.6 × 10 −8 A/cm 2 , and 0.44 V respectively.