International Business Machines Corporation

Other

John R Lankard

Lee Chen

Mark J LaPlante

James L Speidell

Gangadhara Swami Mathad

Donald Stimson Bethune

James G Balz

John J Ritsko

Ajay Prabhakar Giri

James Hammond Brannon

Kurt A Smith

James T Yeh

Peter A Agostino

Peter P Sorokin

Michael M Loy

Steven J Kirch

Ron J McDonald

A laser ablation mask repair method. Defects (holes) are located in a dielectric mask. The surface of the mask above the defect is melted with a CO.sub.2 laser to form a depression in the surface. The depression forms a lens which diffuses ablation laser energy instead of transmitting it. Thus, the ablation laser is prevented from ablating a polymer ablation layer, because the holes are blocked and, the mask is repaired. The method may also be used to make Engineering Changes (EC) laser ablation masks.

Laser ablation mask repair method

A method of patterning a preimidized benzophenone photoactive polymer used as a photoresist with a laser light source improves its crosslinking efficiency and reduces swelling, thereby enabling the formation of lines on the order of microns.

Laser exposure of photosensitive polyimide for pattern formation

The present invention is a mask and methods for making masks for use with a laser projection etching system. The unique mask is able to withstand the fluences of the high energy and high power lasers used without degrading. Specifically, the new projection etching masks are fabricated of patterned multiple dielectric layers having alternating high and low indices of refraction on a UV grade synthetic fused silica substrate in order to achieve maximum reflectivity of the laser energy in the opague areas and maximum transmissivity of the laser energy in the transparent areas of the mask.

High energy laser mask and method of making same

A method for etching a polyimide body which involves directing U.V. radiation having a wavelength between about 240 to 400 nm. onto the body is described. The radiation is continued to be applied to the body for sufficient time to cause a direct etching of the body where the radiation impinges upon the body. The method is particularly useful where the U.V. radiation is passed through a mask located between the source of the ultraviolet radiation and the body so that a radiation pattern is projected onto the body where the direct etching takes place. The etching can be caused to produce openings having a positive slope in the radiation pattern upon the polyimide layer. The advantage of the positive slope is particularly great where a coating such as a metal layer is deposited over the remaining polyimide layer having the openings therein. The positive slope allows the complete filling of the openings.

Patterning of polyimide films with ultraviolet light

Disclosed is a method of etching a metallized substrate by excimer laser radiation. The substrate is exposed to a selected gas, e.g., a halogen gas, which spontaneously reacts with the metal forming a solid reaction product layer on the metal by a partial consumption of the metal. A beam of radiation from an excimer laser, e.g. XeF laser operating at a wavelength of 351 nm or XeCl laser at 308 nm or KrF laser at 248 nm or KrCl laser at 222 nm or ArF laser at 193 nm or F.sub.2 laser at 157 nm, is applied to the reaction product in a desired pattern to vaporize the reaction product and thereby selectively etch the metal with a high resolution.

Laser induced chemical etching of metals with excimer lasers

An intense broadband continuum light pulse of uniform spectral intensity and short time duration is generated. This continuum pulse is then downconverted in frequency to a region of interest, preferably in the infrared region, by applying it as a pump pulse to a molecular or atomic vapor so as to induce stimulated Raman scattering. The resulting Raman Stokes pulse surprisingly tends to have the same spectral bandwidth, intensity uniformity and time duration as the pump continuum pulse. The downconverted continuum pulse (the Raman Stokes pulse) is then used to probe a sample. The sample converts the uniform spectral intensity distribution of the probe pulse into a nonuniform spectral intensity distribution which contains the absorption spectrum of the sample. This spectrum pulse has the same spectral bandwidth and time duration as the Raman Stokes pulse and is finally upconverted in frequency to a region where the spectrum pulse can be conveniently recorded. This is done with a four-wave Raman mixing process in an alkali metal vapor. The vapor is simultaneously pumped with the spectrum pulse and with a second pumping light pulse (or beam) having a frequency in the vicinity of a suitable resonance line of the vapor so as to induce SERS. In the alkali metal vapor, the resulting Raman Stokes pulse and spectrum pulse beat together with the second pumping light pulse to produce an upconverted pulse at a higher frequency band, which surprisingly also tends to have the same spectral bandwidth, intensity distribution (spectrum) and time duration as the spectrum pulse. The upconverted pulse is then recorded either photographically or photoelectrically with conventional spectrographic apparatus.

Time-resolved infrared spectral photography

Growing community of inventors

Mahopac, NY, United States of America

John R Lankard