Abstract: A method and apparatus are described for photoetching organic biological matter without requiring heat as the dominant etching mechanism. Far-ultraviolet radiation of wavelengths less than 200 nm are used to selectively remove organic biological material, where the radiation has an energy fluence sufficiently great to cause ablative photodecomposition. Either continuous wave or pulse radiation can be used, a suitable ultraviolet light source being an ArF excimer laser having an output at 193 nm. The exposed biological material is ablatively photodecomposed without heating or damage to the rest of the organic material. Medical and dental applications include the removal of damaged or unhealthy tissue from bone, removal of skin lesions, cutting or sectioning healthy tissue, and the treatment of decayed teeth.

Abstract: High purity oxidation is produced on a semiconductor substrate. The process includes heating the semiconductor substrate in the presence of an oxidizing ambient in a multi-walled reaction chamber containing a heating element. A halogen-containing ambient flows in an outer portion of the reaction chamber intermediate between the inner portion and the heating element to react with heating element contaminant. In a portion of the reaction chamber position intermediate of the inner portion and the outer portion, a gaseous ambient flows to remove water by-product from the reaction with the halogen which occurs in the outer portion of the reaction chamber. The apparatus for carrying out the above process is also provided.

Abstract: High purity oxidation is produced on a semiconductor substrate. The process includes heating the semiconductor substrate in the presence of an oxidizing ambient in a multi-walled reaction chamber containing a heating element. A halogen-containing ambient flows in an outer portion of the reaction chamber intermediate between the inner portion and the heating element to react with heating element contaminant. In a portion of the reaction chamber position intermediate of the inner portion and the outer portion, a gaseous ambient flows to remove water by-product from the reaction with the halogen which occurs in the outer portion of the reaction chamber. The apparatus for carrying out the above process is also provided.

Abstract: A method is described for photoetching polyimides efficiently, and without the need for any chemical development steps. At least 1000.ANG. of the polyimide are removed by irradiation of the polyimide with ultraviolet radiation having wavelengths less than 220 nm. To enhance the process, the power density of the radiation is greater than about 60 mJ/cm.sup.2. The presence of an atmosphere containing oxygen enhances the etch rate, although photoetching will occur in other atmospheres.

Abstract: A method for depositing a refractory metal onto a substrate wherein a carbonyl compound vapor of the metal in the vicinity of or on the substrate is photodecomposed by ultraviolet radiation of wavelengths less than 200 nm. This causes the release of atoms of the metal, which then condense onto the substrate. In an example, a tungsten layer is photodeposited by this method onto a GaAs semiconductor layer to form a Schottky barrier diode.

Abstract: A technique is described for the fabrication of devices and circuits using multiple layers of materials, where patterned layers of resists are required to make the device or circuit. The fabrication process is characterized by the selective removal of portions of the resist layer by ablative photodecomposition. This decomposition is caused by the incidence of ultraviolet radiation of wavelengths less than 220 nm, and power densities sufficient to cause fragmentation of resist polymer chains and the immediate escape of the fragmented portions from the resist layer. Energy fluences in excess of 10 mJ/cm.sup.2 /pulse are typically required. The deliverance of a large amount of energy in this wavelength range to the resist layer in a sufficiently short amount of time causes ablation of the polymer chain fragments. No subsequent development step is required for patterning the resist layer.

Abstract: A method for high resolution maskless electroless plating is described. Preferential plating results from exposing those regions where plating is sought to an energy beam to increase the plating rate by a factor of 10.sup.3 to 10.sup.4. This enhancement is sufficient to make masking unnecessary.