International Business Machines Corporation

Henry C Schick

Pei-Ching Li

Charles A Cortellino

Joseph E Levine

Bernt Narken

Donald A MacKinnon

Disclosed is a method of treating the surface of a molybdenum mask used for screening a metallized paste pattern to render it smooth and preserve the mask's hardness. The treatment consists of subjecting the mask to a nitridation step by which an ultrathin layer of molybdenum layer is first formed, followed by deposition of a comparatively thick silicon nitride layer thereon. The nitridation step may be accomplished in a plasma deposition system using either forming gas, ammonia or gas mixture of nitrogen and ammonia at a predetermined low temperature and pressure. The silicon nitride deposition may be accomplished in the same system at the same temperature and pressure by substituting the gas utilized to form the molybdenum nitride with a gaseous mixture of silane and one of nitrogen and ammonia.

Surface treatment of a molybdenum screening mask

This developer station comprises a developing tank arranged with a centrally located rotatable and vertically translatable shaft carrying a workpiece platform at the upper end thereof. Initially, the platform is located above the tank for ease in loading a workpiece, for example an exposed photoresist coated semiconductor device component. The workpiece is then lowered into developing solution in the tank where it is rotated and oscillated vertically for agitational action during a predetermined time period after which it is raised up out of the solution and delayed at a drying station for another predetermined time period. Thereafter, the workpiece is returned to the initial position for unloading.

Developing apparatus for exposed photoresist coated wafers

A photomask formed of a transparent dielectric substrate, such as glass and quartz based substrates, having a conductive surface adjacent region, which is patterned with sequential overcoatings of a composite chrome oxide layer and a chrome film. The mask comprises a combination of varied reflectivities to provide proper densities for the opaque areas of the mask.

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Hopewell Junction, NY, United States of America

Henry C Schick