Abstract: A method for preventing the formation of watermark defects includes the steps of forming a pad oxide, a silicon nitride layer and a silicon oxynitride layer over a semiconductor substrate. A photoresist mask is formed over the resulting structure, with the silicon oxynitride layer being used as an anti-reflective coating during exposure of the photoresist material. An etch is performed through the photoresist mask, thereby forming a trench in the substrate. The photoresist mask is stripped, and the silicon oxynitride layer is conditioned. For example, the silicon oxynitride layer may be conditioned by a rapid thermal anneal in the presence of oxygen or nitrogen. A wet clean step is subsequently performed to remove a native oxide layer in the trench. The conditioned silicon oxynitride layer prevents the formation of watermarks during the wet clean process.

Abstract: A method for preventing the formation of watermark defects includes the steps of forming a pad oxide, a silicon nitride layer and a silicon oxynitride layer over a semiconductor substrate. A photoresist mask is formed over the resulting structure, with the silicon oxynitride layer being used as an anti-reflective coating during exposure of the photoresist material. An etch is performed through the photoresist mask, thereby forming a trench in the substrate. The photoresist mask is stripped, and the silicon oxynitride layer is conditioned. For example, the silicon oxynitride layer may be conditioned by a rapid thermal anneal in the presence of oxygen or nitrogen. A wet clean step is subsequently performed to remove a native oxide layer in the trench. The conditioned silicon oxynitride layer prevents the formation of watermarks during the wet clean process.

Abstract: Methods for forming nitrided oxides in semiconductor devices by rapid thermal oxidation, in which a semiconductor substrate having an exposed silicon surface is placed into a thermal process chamber. Then, an ambient gas comprising N2O and an inert gas such as argon or N2 is introduced into the process chamber. Next, the silicon surface is heated to a predefined process temperature, thereby oxidizing at least a portion of the silicon surface. Finally, the semiconductor substrate is cooled. An ultra-thin oxide layer with uniform oxide characteristics, such as more boron penetration resistance, good oxide composition and thickness uniformity, increased charge to breakdown voltage in the oxide layer, can be formed.

Abstract: A process for preparing optically active allylic alcohol derivatives comprises reacting a racemic mixture of the following formula I ##STR1## wherein R is alkyl, alkenyl, or substituted or unsubstituted aryl or arylalkyl;with acetate or anhydride under the catalysis of Pseudomonase AK, PS or K-10 lipase in the presence of an organic solvent.