Patricia A. Bianconi

Poly(phenylcarbyne): A Polymer Precursor to Diamond-Like Carbon.

The synthesis of poly(phenylcarbyne), one of a class of carbon-based random network polymers, is reported. The network backbone of this polymer is composed of tetrahedrally hybridized carbon atoms, each bearing one phenyl substituent and linking, by means of three carbon-carbon single bonds, into a three-dimensional random network of fused rings. This atomic-level carbon network backbone confers unusual properties on the polymer, including facile thermal decomposition, which yields diamond or diamond-like carbon phases at atmospheric pressure.

Reductive coupling of two carbon monoxide ligands to form a coordinated alkyne

Etude du couplage reducteur de CO pour former une nouvelle espece de produit derive de CO, Me 3 SiOC≡COSiMe 3 stabilise par coordination a Ta. Structure moleculaire du produit obtenu: [Ta(Me 3 SiOC≡COSiMe 3 )(dmpe) 2 Cl]

Surface-Imaged Silicon Polymers for 193-nm Excimer Laser Lithography

A negative-tone surface-imaged resist process based upon the area-selective oxidation of silicon-backbone polymers, is described. A bromine-based plasma is the resist developer, where the oxidized polymer inhibits the bromine-initiated etching to yield a negative-tone image. Using either polysilanes or polysilynes, resist sensitivities in the range of 50 mJ/cm2 have been obtained and resolutions to 0.2 µm achieved. Photosensitizers can be added to further accelerate the photoxidation, resulting in sensitivities less than 20 mJ/cm2. The latent image formation is reciprocal with respect to fluence in the range 0.05 to 1.5 mJ/cm2 per pulse and with respect to repetition rate. The photooxidation contrast is one, whereas the bromine-based etch step can have a contrast as high as 5. In addition, the exposure, focus, and development latitudes have all been characterized and compared to other surface-imaged 193-nm resist systems. When high-ion-density plasma sources are used, throughput levels appropriate for single-wafer processing can be achieved.

Polysilyne resists for 193 nm excimer laser lithography

Polyalkylsilynes have been used as resists for 193-nm projection lithography. These resists can be either wet developed using toluene or dry developed using HBr reactive ion etching (RIE). Wet development relies on crosslinking via intermolecular Si-O-Si bond formation to reduce solubility (negative tone) whereas the dry development relies on photo-oxidation to induce etch selectivity (also negative tone). The sensitivity in either case ranges from 20 to 200 mJ/cm2 and depends on the resist formulation. The best resist compositions are those that contain predominantly small (n-butyl) aliphatic pendant groups rather than large (cyclohexyl, phenyl) pendant groups. Using a 0.33 NA catadioptric lens with a phase mask, equal line-and-space features as small as 0.15 micrometers have been printed and transferred through 1.0 micrometers of planarizing layer (aspect ratio > 6) using oxygen RIE.