Abstract: The positioning system, particularly useful for moving a stage mounting a semiconductor wafer for the manufacture of semiconductor devices, provides a lead screw and zero backlash nut for coarse motion of the stage. A thrust member fixedly mounts the nut and the member is flexurally mounted to a housing supporting the stage acting through a piezoelectric motor connection. This action brings the stage in a coarse adjustment mode into the capture range of the piezoelectric motor for fine adjustment by in and out movement of a pusher rod extending from the motor. Flexures allow motion of the thrust member parallel to the lead screw and protects the piezoelectric motor from undesirable side loads. A separate duplicate mechanism is used for each of x-axis and y-axis movements of the housing and stage to bring the stage to a precise position by the respective coarse and fine translationary movements of the lead screw, thrust members and piezoelectric motors.

Abstract: A process for manufacturing a mask for use in X-ray photolithography begins with a step of providing a glass disk (50) which is coated with a layer of boron nitride (52). The glass disk is about 1/4 of an inch thick and about 4.5 to 6 inches in diameter. A circular portion (50a) of the boron nitride layer on one side of the glass disk is removed thus exposing a circular portion of the glass disk. The exposed portion of the glass disk is then removed, leaving a glass ring coated with a boron nitride membrane on one side. A layer of polyimide (54) and a layer of x-ray opaque substance (58) is deposited on the boron nitride membrane. The x-ray opaque substance is then patterned, the resulting structure being a mask which is used in X-ray photolithography.

Abstract: An optical alignment apparatus and method for a semiconductor lithography mask and wafer utilizes two monochromatic light sources of different wavelengths. The mask contains targets in the form of linear Fresnel zone plates and the wafer contains a reflecting grating. Incident illumination from the two light sources illuminates the mask targets and is reflected from the wafer gratings in various intensity depending on the physical characteristics of the wafer and mask layers and thicknesses and by the targets. A detector detects the strongest of the diffracted return beams from each of the monochromatic light sources and uses the strongest to align the targets and grating on the mask and wafer for more accurate printing of mask patterns on the wafer.

Abstract: An x-ray mask membrane reflection compensator includes an x-ray chamber having a transmitting gaseous media therein chamber through which x-rays are directed to a mask membrane that is positioned in close spaced proximity to a resist-coated wafer. A controlled environment of processing gas is provided within a gap between the mask membrane and wafer surfaces. The processing gas and gaseous media pressures variously cause bulging of the membrane resulting in a descrepancy in the gap distance across the field of view. A laser source provides an incident beam of light which is directed at an incident angle to the mask membrane and the wafer surface such that return beams are reflected and interference fringe patterns, due to slight nonparallelism of the mask membrane and the wafer are displayed on a monitor.

Abstract: An additive process for manufacturing a mask (113) used in x-ray photolithography includes the step of coating a boron nitride layer (102) with a layer of indium tin oxide (104) and a second layer of boron nitride (106). The second boron nitride layer is patterend and used as a stencil during a plating process while the indium tin oxide layer is used as a plating base. Because boron nitride and thin indium tin oxide are both x-ray transparent, neither the stencil nor the plating base need be removed during the manufacturing process.

Abstract: A method for manufacturing a mask (100) for use in x-ray photolithographic processes includes the step of coating a silicon wafer (10) with a layer of boron nitride (12). A masking substance (14) is used to coat one side of the boron nitride coated wafer, and the boron nitride is etched off of the other side of the wafer. The wafer (10) is then bonded to a pyrex ring (16) using a field assisted thermal bonding process. During the field assisted thermal bonding process, the silicon (11) is bonded directly to the pyrex (16). Then, a zirconium layer (24) is used to cover the mask and is selectively etched where it is desired to remove a circular portion of the silicon. Thereafter the silicon is subjected to a semianisotropic etch. The remaining structure includes a pyrex ring bonded to a silicon ring across which a layer of boron nitride is stretched. The layer of boron nitride is subjected to an annealing process and is then coated with an x-ray opaque material.

Abstract: A process for manufacturing a mask for use in x-ray photolithography starts with the step of coating the first and second sides of a silicon wafer (100) with a boron nitride layer (102). The first side of the wafer (100) is coated with a polyimide layer (104) which serves as a primary x-ray transparent layer for supporting a subsequently deposited x-ray opaque material. The first and second sides of the wafer (100) are then covered with a second boron nitride layer (106). The second side of the wafer (100) is then bonded to a support structure such as a pyrex ring (108). A portion of the first and second boron nitride layers (102, 106) is then removed thus exposing a portion of the underlying silicon substrate (101). The exposed portion of the silicon substrate is then removed thus leaving a ring which supports an x-ray transparent membrane comprising the first boron nitride layer (102), the polyimide layer (104) and the second boron nitride layer (106).

Abstract: A method of manufacturing a mask for use in x-ray photolithography includes the steps of coating a set of wafers (20) with boron nitride (22). The tension in the boron nitride is measured by using a capacitive probe (26) to measure bowing in a set of test wafers. The remaining wafers are attached to a pyrex ring (28), and the boron nitride is removed from one side of the wafers. A circular hole is then etched in the wafer, and a layer of tantalum (32) and gold (34) are formed on the remaining boron nitride membrane. The gold (34) is patterned via a sputter etching process. Power is reduced at the end of the sputter etching process slowly to reduce mechanical stress in the mask. The tantalum (32) is then etched via a reactive ion etching process. In this way, an x-ray transparent boron nitride membrane is used to support x-ray opaque gold.

Abstract: A controlled flow of X-ray attenuating gas such as helium is provided to an upper portion of a beam exposure chamber. A vent tube (21) extends from a lower portion of the chamber adjacent a mask to an exterior exit orifice (23) positioned at mask level to prevent ingress of air to the chamber and prevent mask membrane deflecton and change in the mask-to-silicon wafer substrate gap distance. The substrate (20) is positioned below the mask membrane and is surrounded by a mask-to-wafer zone into which is flowed a substrate fabrication process gas which is vented either by a gas flange (25) in spaced gapped relation to the mask holder and mask, or by a vent tube (46) extending from the zone to an orifice end (46a) approximate the level of the mask. There is then no pressure differential on the top and bottom surfaces of the mask membrane affecting the mask-to-wafer gap distance (8) during substrate fabrication operations.

Abstract: A method of manufacturing a mask for use in x-ray photolithography includes the steps of coating a set of wafers (20) with boron nitride (22). The tension in the boron nitride is measured by using a capacitive probe (26) to measure bowing in a set of test wafers. The remaining wafers are attached to a pyrex ring (28), and the boron nitride is removed from one side of the wafers. A circular hole is then eteched in the wafer, and a layer of tantalum (32) and gold (34) are formed on the remaining boron nitride membrane. The gold (34) is patterned via a sputter etching process. Power is reduced at the end of the sputter etching process slowly to reduce mechanical stress in the mask. The tantalum (32) is then etched via a reactive ion etching process. In this way, an x-ray transparent boron nitride membrane is used to support x-ray opaque gold.