International Business Machines Corporation

Other

Rangaswamy Srinivasan

Samuel E Blum

Karen H Brown

Bodil E Braren

Veronica I Mayne-Banton

Ari Aviram

James Jeffrey Wynne

Karen Lynne Holloway

Kathleen A Perry

Alvin Sugerman

Channabasappa S Angadiyavar

Pamela A Leary-Renick

A method for providing superior fill of features in semiconductor processing utilizes a laser ablation system. Deposition is obtained by ablating target materials which are driven off perpendicular to the target in the direction of the deposition surface. The method provides complete fill of high aspect ratio features with nominal heating of the substrate. Alloys and graded layers, as well as pure metals, can be deposited in low temperature patterned layers. In addition, the system has been used to achieve superior trench filling for isolation structures.

Deposition method for high aspect ratio features using photoablation

A beam (12) of continuous wave ultraviolet light having a wavelength that is absorbed by an organic solid (20) is focused to a spot (18) on a surface of the organic solid (20). Relative motion is imparted between the beam (12) and organic solid (20) at a rate that defines, together with a dimension of the spot (18), an effective pulse width. Within prescribed ranges of the wavelength, power density and effective pulse width, a new cutting regime was discovered whereby organic solids can be cut at rates and with a quality of cuts previously requiring pulsed ultraviolet laser sources.

Cutting of organic solids by continuous wave ultraviolet irradiation

A method and apparatus are described which enhance the ablative effect of a UV laser. The ablative effect of a pulsed UV laser is enhanced using a second, longer wavelength pulsed laser. Each pulse of the first laser is followed by or combined with a pulse from the second laser. The etch depth per pulse is controlled by varying the time between pulses from the first and second lasers. The maximum etch depth per pulse occurs at a time separation which is a function of the substrate being etched. The first laser wavelength is selected to be within the absorption spectrum of the unexcited surface molecules of the substrate, while the wavelength of the second laser is selected to be within the absorption spectrum of the surface molecules excited by the incident radiation of the first laser.

Enhancement of ultraviolet laser ablation and etching organic solids

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.

Far ultraviolet surgical and dental procedures

In the fabrication of an interconnection package for a plurality of semiconductors or integrated circuit chips wherein a multi-layered glass or glass-ceramic superstructure with a multi-layered distribution of planar conductors is formed by a process forming vertical conductive interconnection or studs between planar conductor layers, by pre-forming a via configuration in each glass or glass-ceramic layer at the interconnection points followed by depositing the conductive studs therein. The via configuration is formed by defining a desired pattern of vias, and ablating the vias through the top of and through the glass or glass-ceramic layer, using an ultraviolet laser. The vias may be stepped-shoulder or counter-bored by using a two mask operation.

Formation of a multi-layer glass-metallized structure formed on and

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.

Patterning of polyimide films with far ultraviolet light

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.

Photo deposition of metals with far UV radiation

A method for selective electroless deposition of a metal (Cu, Ni, Au, Ag) onto a polyester substrate, such as poly(ethylene terephthalate) is described. A combination of ultraviolet exposure of wavelengths &lt;220 nm and a pre-treatment step is used to obtain selective electroless deposition. The polyester layer is first irradiated with uv light of wavelengths &lt;220 nm and is then subjected to a pre-plating pre-treatment with a basic solution. After this, the desired metal is deposited by conventional electroless deposition. Substantial deposition will occur only in those areas which were both exposed to the uv light and subjected to the pre-plating treatment.

Method for depositing a metal layer on polyesters

A technique is described for photoetching polyesters, such as polyethylene teraphthalate (PET), efficiently, and without causing degradation or heating of the bulk of the PET material. At least about 1000.ANG. of the polyester are removed by application of ultraviolet radiation having wavelengths less than 220 nm. To enhance the process, irradiation can occur in the presence of oxygen or air.

Self developing, photoetching of polyesters by far UV radiation

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.

Far UV patterning of resist materials

New 2,4,6 trisubstituted pyridines are useful as laser dyes. These dyes are used in solution with a non-interfering solvent to form lasing media useful in dye lasers. When excited, these dyes have emission wavelengths which cover the spectrum from 410-570 nm. The violet and near ultra-violet regions of the visible spectrum are particularly well-served by the new compounds.

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Ossining, NY, United States of America

Rangaswamy Srinivasan