International Business Machines Corporation

Andrew J Watts

Jed Hickory Rankin

John Edward Cronin

James Gardner Ryan

Carter W Kaanta

David V Horak

Randy William Mann

Paul A Farrar, Sr

Paul A Farrar

Robert Michael Geffken

Rosemary A Previti-Kelly

Edward W Conrad

James Allan Bruce

Emily Gallagher

Michael James Lercel

Ronald R Uttecht

Daniel C Cole

Paul William Pastel

Kenneth Christopher Racette

Craig E Schneider

William H Guthrie

John S Smyth

Rogert K Leidy

A method and system for designing a photomask. The method provides a single machine methodology for inspecting photomasks having regions that repeat and regions that do not repeat. The method includes generating a chip dataset representing an integrated circuit chip design to be included in a cell region of a photomask, generating a kerf dataset to be included in the cell region, generating a kerf copy dataset, and merging the chip dataset, the kerf dataset and the kerf copy dataset into a photomask dataset representing a pattern of clear and opaque regions of the photomask.

Structure and methodology for fabrication and inspection of photomasks by a single design system

A photomask, method of designing, of fabricating, of designing, a method of inspecting and a system for designing the photomask. The photomask, includes: a cell region, the cell region comprising one or more chip regions, each chip region comprising a pattern of opaque and clear sub-regions corresponding to features of an integrated circuit chip and one or more kerf regions, each kerf region comprising a pattern of opaque and clear sub-regions corresponding to features of an integrated circuit kerf; a clear region formed adjacent to a side of a copy region, the copy region comprising opaque and clear sub-regions that are copies of at least a part of the cell region; and an opaque region between the clear region and the cell region.

Structure and methodology for fabrication and inspection of photomasks

A method to correct critical dimension errors during a semiconductor manufacturing process. The method includes providing a first semiconductor device. The first semiconductor device is analyzed to determine at least one critical dimension error within the first semiconductor device. A dose of electron beam exposure to correct the at least one critical dimension error during a subsequent process to form a second semiconductor device, or during modification of the first semiconductor device is determined. The subsequent process comprises providing a semiconductor structure. The semiconductor structure comprises a photoresist layer on a semiconductor substrate. A plurality of features are formed in the photoresist layer. At least one feature of the plurality of features comprises the at least one critical dimension error. The at least one feature comprising the critical dimension error is corrected by exposing the at least one feature to an electron beam comprising the dose of electron beam exposure, resulting in reduction of the size, or shrinkage, of the at least one feature comprising a critical dimension error.

Method to selectively correct critical dimension errors in the semiconductor industry

A method of making an embedded attenuated phase shift mask (EAPSM) comprises initially providing a phase shift mask substrate having a layer of phase shifting material and a layer of an opaque material, and depositing a first resist layer on the substrate. The first resist layer is exposed by a direct write electron beam or laser energy source and developed, and the substrate is etched, to create first level phase shifting image segments on the substrate corresponding to areas of critical structures to be exposed with the EAPSM. The method then includes depositing a second resist layer on the substrate. Using a single frame exposure mask corresponding to non-critical areas outside the critical structure areas, the second resist layer is then exposed by simultaneous projection exposure. The method then includes developing the second resist layer and etching the substrate to remove the opaque material from the critical structure areas.

Common second level frame exposure methods for making embedded attenuated phase shift masks

A method is provided for patterning a substrate. In such method a first mask, for example, a front-end-of-line ('FEOL') mask is fabricated, the first mask including a plurality of first features such as FEOL features which are usable to pattern regular elements and redundancy elements of a substrate such as a microelectronic substrate and/or a micro-electromechanical substrate. The first mask is tested, i.e., inspected for defects in the features. Thereafter, a second sequentially used mask, for example, a back-end-of-line ('BEOL') mask is fabricated which includes a plurality of second features, e.g., BEOL features, such features being usable to pattern a plurality of interconnections between individual ones of the regular elements and between the regular elements and the redundancy elements. The regular elements and the redundancy elements are patterned using the first mask and the interconnections between them are patterned using the second mask. As a result, the interconnections are patterned in a way that corrects for the detected defects in the first mask.

Method of patterning a substrate by feeding mask defect data forward for subsequent correction

A monolithic optical pellicle and method of making used to protect a photomask during photolithography processing. The monolithic optical pellicle is comprised of a pellicle plate having a recessed central portion integrally formed with a perimeter frame of the pellicle plate such that it is a one-piece optical pellicle. The monolithic optical pellicle comprises a material of sufficient rigidity to minimize distortions in and maximize durability of the pellicle when used in combination with the recessed portion having a thickness that prevents sagging thereof due to applied forces on the resultant monolithic optical pellicle. This recessed central portion is the optical pellicle portion of the present monolithic optical pellicle, while the integral perimeter frame is used to attach the monolithic optical pellicle at the desired stand-off distance to a photomask. The monolithic optical pellicle preferably comprises a material that is transparent to an exposure field at about 157 nm wavelengths.

Monolithic hard pellicle

A method of implementing a new reticle for manufacturing semiconductors on a wafer which involves performing measurements on the reticle and assigning an initial exposure dose by using a predetermined algorithm. The exposure control system utilizes reticle CD data for automatically calculating reticle exposure offset values, i.e. reticle factors. A correlation of reticle size deviations to calculated reticle factors is used to derive a reticle factor for the new reticle. The derived reticle factor is then used to predict an initial exposure condition for the new reticle which is applied to the lithography tool for achieving a wafer design dimension.

Method of photolithographic critical dimension control by using reticle measurements in a control algorithm

The present invention provides a method of forming nested and isolated images in a photosensitive resist. In the disclosed method, the entire surface of the photosensitive resist or selected regions thereof is exposed to a first mask having a set of nested, i.e. repeating pattern or grid images thereon, and then exposed to a second mask in order to remove unwanted portions of the nested image, so as to provide regions of nested and regions of isolated images in said photosensitive resist. The method may also be used to form regions having images in proximity to one another and regions having isolated images by exposing the entire surface of the photosensitive resist to a first mask having repeating patterns, and then removing entire or portions of the repeating patterns by exposure of the photosensitive resist with a second mask.

Method of forming resist images by periodic pattern removal

A mask ( ) with linewidth compensation and a method of making same. The mask provides for optimized imaging of isolated patterns ( ) and nested patterns ( ) present on the same mask. The compensated mask is formed from an uncompensated mask ( ) and comprises an upper surface ( ) upon which the isolated and nested patterns are formed. The isolated pattern comprises a first segment ( ) having first sidewalls ( S). The nested pattern comprises second segments ( ) proximate each other and having second sidewalls ( S). A partial conformal layer ( ) covers the first segment and has feet ( ) outwardly extending a distance d from the first sidewalls along the upper surface. The feet are preferably of a thickness that partially transmits exposure light.

Mask with linewidth compensation and method of making same

A gray level mask suitable for photolithography is constructed of a transparent glass substrate which supports plural levels of materials having different optical transmissivities. In the case of a mask employing only two of these levels, one level may be constructed of a glass made partially transmissive by substitution of silver ions in place of metal ions of alkali metal silicates employed in the construction of the glass. The second layer may be made opaque by construction of the layer of a metal such as chromium. The mask is fabricated with the aid of a photoresist structure which is etched in specific regions by photolithographic masking to enable selective etching of exposed regions of the level of materials of differing optical transmissivities. Various etches are employed for selective etching of the photoresist, the metal of one of the layers, and the glass of the other of the layers. The etches include plasma etch with chloride ions to attack the chromium of the opaque layer, compounds of fluorine to attack the glass layer, and reactive ion etching with oxygen to attack the photoresist structure. Also, developer is employed for etching on hardened regions of resist in the photoresist structure.

Gray level mask

Method of making a gray level mask

A sequence of masking steps reduces the amount of transference of a workpiece among work stations and reduces certain tolerances required for mask alignment in the construction of integrated circuits, and a gray level mask suitable for photolithography. In the integrated circuit, masking layers are developed directly in a wafer for delineating vertical and horizontal portions of an electrically conductive path. The mask is constructed of a transparent glass substrate which supports plural levels of materials having different optical transmissivities. In the case of a mask employing only two of these levels, one level may be constructed of a glass made partially transmissive by substitution of silver ions in place of metal ions of alkali metal silicates employed in the construction of the glass. The second layer may be made opaque by construction of the layer of a metal such as chromium. Both the wafer and the mask are fabricated by a photoresist structure which is etched in specific regions by photolithographic masking to enable selective etching of exposed regions of the level of materials of differing optical transmissivities. Various etches are employed for selective etching of the photoresist and other ones of the layers. The etches include plasma etch with chloride ions to attack the chromium of the opaque layer, compounds of fluorine to attack the glass layer, and reactive ion etching with oxygen to attack the photoresist structure.

Growing community of inventors

Essex, VT, United States of America

Andrew J Watts