International Business Machines Corporation

Alan D Wilson

Kevin K Chan

Peter Vettiger

Ernest Bassous

Alfred Mack

Tai-Hon P Chang

Istvan Lovas

Joseph M Blum

Charles A Gaston

Brian C O'Neill

Constantino Lapadula

Warren J Pinckney

Charles H Locke

Angela C Lamberti

Karl W Beumer

The method of fabrication of a monolithic silicon membrane structure in which the membrane and its supporting framework are constructed from a single ultra thick body of silicon. The fabrication sequence includes the steps of providing a doped membrane layer on the silicon body, forming an apertured mask on the silicon body, and removal of an unwanted silicon region by mechanical grinding and chemical etching to provide a well opening in the silicon body terminating in the doped membrane.

Monolithic silicon membrane device fabrication process

A high precision, high throughput submicrometer workpiece positioning system, particularly useful as a workpiece positioning means in electron beam lithography tools. The positioning system increases mechanical stability by essentially eliminating mechanical hysteresis, which allows state of the art electron beam lithography systems to provide the repeatable, accurate and dense circuit patterns that modern semiconductor trends demand. The positioning system in preferred form comprises a movable positioning table, a workpiece supporting superstructure which is elastically joined to the movable positioning table by three geometrically distinct kinematic support means and a two-stage coupling means which mounts a workpiece (i.e., semiconductor mask or wafer) to the workpiece supporting superstructure. A laser interferometer locating-positioning system is utilized to position the workpiece. The interferometer mirrors are integral with the workpiece supporting superstructure. The coupling means mounts a workpiece to the workpiece supporting superstructure with a minimum of mechanical distortion. Three two-stage coupling means are utilized in preferred form. The first stage is removable from the positioning, and allows for workpiece loading and unloading outside of the positioning system. The removable stage comprises an integral unit which includes two opposing arms with large radii spherical ends and a tab member. The spherical end center lines are collinear, providing for vertical clamping of the workpiece. The second stage is stationary and integral with the workpiece supporting superstructure. The stationary stage comprises two opposing arms with large radii spherical ends and clamps the tab of the removable stage by vertical clamping.

Workpiece mounting and clamping system having submicron positioning

A large lithographic pattern is written as quickly as possible by writing successive subpatterns in a vector scan mode of operation without any interruption between successive subpatterns. This is made possible by arranging the subpatterns so that they are adjacent to each other and are preferably overlapping and by gradually moving the workpiece with respect to the writing field so as to always keep the subpattern being written within the writing field of the beam. The speed and direction of the workpiece movement (relative to the writing field) is not predetermined for all patterns but is controlled instead by the pattern being written. A sparsely written pattern or portion of a pattern is accompanied by a more rapid table movement than what accompanies a densely written pattern or portion of a pattern. This is made possible by embedding pattern determined workpiece movement commands within the pattern defining data. Through the workpiece movement commands, relative movement between the workpiece and the writing field may be continuously controlled with respect to movement direction, velocity and acceleration. The desired relative position of the workpiece is continuously updated in tiny increments while a laser interferometer control system measures the error between the actual workpiece position and the desired workpiece position and causes the workpiece to track the desired position.

Continuously writing electron beam stitched pattern exposure system

An electron beam fabricated mask used in the production of integrated circuits is tested by a method that includes the steps of forming a print of the mask and then inspecting the print by writing the same electron beam pattern or complement thereof on the print and detecting pattern coincidence and non-coincidence with a vector scan system.

Method of inspecting a mask using an electron beam vector scan system

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Armonk, NY, United States of America

Alan D Wilson