Polysulfone based Non-CA resists for 193nm immersion lithography: Effect of increasing polymer absorbance on sensitivity

The use of norbornene-based polysulfones as non-chemically amplified resists (non-CARs) for 193 nm immersion lithography was explored. Allylbenzene was incorporated into the polymer backbone to increase the absorbance of the polymers. The effect of polymer absorbance on sensitivity to 193 nm radiation was investigated. Polymer films on silicon wafers have been irradiated with 193 nm photons in the absence of a photo-acid generator. Chemical contrast curves (film thickness versus dose plots prior to solvent development) and contrast curves (film thickness versus dose plots after solvent development) were obtained by spectroscopic ellipsometry. The results show that E0 values could be reduced significantly by increasing the absorbance of the polymer

Simultaneous swelling and degradation of crosslinked PEG-PLLA networks

Trauma or inflammatory conditions such as periodontitis are caused by the loss of alveolar bone which supports and surrounds the teeth. A method to induce predictable bone formation or regeneration would have wide application in periodontal therapy and treatment of bone loss associated with dental implant failure. Synthetic polymeric biomaterials with injectability and biodegradability have been increasingly used in tissue engineering. They are easy to apply, will improve the patient's compliance and comfort, and the delivery of the scaffold is confined to the specific site of action. In this paper, two distinct polymerization chemistries, conventional free radical polymerization and thiol-ene polymerization, were used to synthesize functional networks based on PEG-PLLA networks with varying basic structure. The relationships between the network structure and the material degradation behavior and properties were examined. The aim of this study is to determine the rate and mechanism of degradation of the network under physiologically-relevant conditions

Electron-beam induced freezing of an aromatic based EUV resist: a robust template for directed self assembly of block copolymers

Resist freezing is routinely used in lithography applications to facilitate double patterning and the directed self assembly (DSA) of block copolymers. Previous reports of graphoepitaxy within patterned positive-tone resists used chemical freezing agents which are known to cause significant shrinkage of critical dimensions (CD). We report the 'freezing' of an aromatic-based EUV resist by exposure to an electron beam, so did not require the use of chemical agents. Crucially, the process did not lead to significant changes in CD and line edge roughness (LER), where the frozen patterns were resistant to treatment with solvents and annealing to temperatures well above the glass transition temperature of the uncrosslinked resist. Finally, we take advantage of these properties and demonstrate the utility of this process for applications in the directed self assembly of block copolymers leading to pattern multiplication