Mr. Gary R. Newman Profile

Gary R. Newman

Key Account Manager at Nikon Precision Inc

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Publications (9)

Proceedings Article | 12 May 2005 Paper

An investigation of the photolithographic contributors to wafer-level colinearity in thin film head manufacturing

Gary Newman, Hai Sun

Proceedings Volume 5754, (2005) https://doi.org/10.1117/12.596885

KEYWORDS: Manufacturing, Reticles, Semiconducting wafers, Distortion, Head, Thin films, Thin film manufacturing, Imaging systems, Lithography, Error analysis

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Proceedings Article | 2 June 2000 Paper

Wafer-level colinearity monitoring for TFH applications

Patrick Moore, Gary Newman, Kelly Abreau

Proceedings Volume 3998, (2000) https://doi.org/10.1117/12.386510

KEYWORDS: Reticles, Distortion, Metrology, Head, Manufacturing, Lithography, Semiconducting wafers, Error analysis, Diagnostics, Measurement devices

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Advances in thin film head (TFH) designs continue to outpace those in the IC industry. The transition to giant magneto resistive (GMR) designs is underway along with the push toward areal densities in the 20 Gbit/inch² regime and beyond. This comes at a time when the popularity of the low-cost personal computer (PC) is extremely high, and PC prices are continuing to fall. Consequently, TFH manufacturers are forced to deal with pricing pressure in addition to technological demands. New methods of monitoring and improving yield are required along with advanced head designs. TFH manufacturing is a two-step process. The first is a wafer-level process consisting of manufacturing devices on substrates using processes similar to those in the IC industry. The second half is a slider-level process where wafers are diced into 'rowbars' containing many heads. Each rowbar is then lapped to obtain the desired performance from each head. Variation in the placement of specific layers of each device on the bar, known as a colinearity error, causes a change in device performance and directly impacts yield. The photolithography tool and process contribute to colinearity errors. These components include stepper lens distortion errors, stepper stage errors, reticle fabrication errors, and CD uniformity errors. Currently, colinearity is only very roughly estimated during wafer-level TFH production. An absolute metrology tool, such as a Nikon XY, could be used to quantify colinearity with improved accuracy, but this technique is impractical since TFH manufacturers typically do not have this type of equipment at the production site. More importantly, this measurement technique does not provide the rapid feedback needed in a high-volume production facility. Consequently, the wafer-fab must rely on resistivity-based measurements from slider-fab to quantify colinearity errors. The feedback of this data may require several weeks, making it useless as a process diagnostic. This study examines a method of quickly estimating colinearity at the wafer-level with a test reticle and metrology equipment routinely found in TFH facilities. Colinearity results are correlated to slider-fab measurements on production devices. Stepper contributions to colinearity are estimated, and compared across multiple steppers and stepper generations. Multiple techniques of integrating this diagnostic into production are investigated and discussed.

Proceedings Article | 30 August 1999 Paper

Resolution enhancement techniques for submicron deep trench processes

Lijun Tong, Joyce Hsiang, Kuanchih Lin, Gary Newman

Proceedings Volume 3874, (1999) https://doi.org/10.1117/12.361233

KEYWORDS: Head, Data storage, Photoresist materials, Magnetism, Microelectromechanical systems, Thin films, Lithography, Optical lithography, Manufacturing, Chemical elements

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Proceedings Article | 14 June 1999 Paper

Application of resolution enhancement techniques in thin film head processing

Lijun Tong, Joyce Hsiang, Johnny Gossett, Gary Newman, Kelly Abreau, Tzu-chin Chuang

Proceedings Volume 3677, (1999) https://doi.org/10.1117/12.350869

KEYWORDS: Photoresist materials, Head, Thin films, Lithography, Scanning electron microscopy, Reticles, Resolution enhancement technologies, Coherence (optics), Cadmium, Photography

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Proceedings Article | 7 July 1997 Paper

Advanced simulation techniques for thick photoresist lithography

Warren Flack, Gary Newman, Douglas Bernard, Juan Rey, Yuri Granik, Victor Boksha

Proceedings Volume 3049, (1997) https://doi.org/10.1117/12.275881

KEYWORDS: Photoresist materials, Photoresist developing, Lithography, Semiconducting wafers, Optical lithography, Thin films, Refractive index, Computer simulations, Critical dimension metrology, Energy coupling

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Proceedings Article | 7 July 1997 Paper

Simulation of subhalfmicron-mask defect printability at 1X reticle magnification

Warren Flack, Gary Newman, Dan Schurz

Proceedings Volume 3050, (1997) https://doi.org/10.1117/12.275910

KEYWORDS: Reticles, Opacity, Semiconducting wafers, Critical dimension metrology, Data modeling, Lithography, Optical proximity correction, 3D metrology, Optical simulations, Photoresist materials

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There has been considerable attention given to the printability of reticle defects and their impact on wafer yields. Over the last year the printability risk from small defects increased due to the wider application of optical proximity correction structures and the inclusion of more phase shifting retictles. There have been several simulation studies on the printability of sub-halfmicron defects using lens and illumination parameters of 5X reduction steppers. Since submicron 1X projection systems are being incorporated into numerous fabricant lines, there is a clear need to determine if these system show similar sensitivity to sub- halfmicron defects as reduction steppers. Earlier experimental work examined the printability of several classes of sub-halfmicron 25 micrometers defects on a submicron 1X stepper. To extend this work, a 3D optical lithography simulation tool has been employed to predict the printablity of various reticle defect scenarios. Experimental data was used to validate the 3D simulator by comparing modeling data to SEM measurements of wafers exposed with a reticle containing programmed clear pinhole and opaque pindot defects. A statistically designed simulation study was performed to quantify the critical dimension variation resulting from defects of varying size, proximity to a feature edge and variation in the pitch of the impacted line/space features. An additional statistically designed simulation was then use to predict the printability behavior of defects relative to different features sizes over a range of numerical aperture and partial coherence settings applicable to a 1X lens design. Finally, the impact of defect length and width on printability were characterized for rectangular defects over a range of sizes. Overall, this analysis enhances the understanding of the relationship between reticle defects and 1X projection optics and allows for determination of optical reticle defect specifications for cost effective lithography applications.

Proceedings Article | 12 February 1997 Paper

Printability of 1X reticle defects for submicron design rules

Dan Schurz, Warren Flack, Gary Newman

Proceedings Volume 3236, (1997) https://doi.org/10.1117/12.301217

KEYWORDS: Reticles, Opacity, Lithography, Semiconducting wafers, Scanning electron microscopy, Computer aided design, Critical dimension metrology, Photoresist materials, Optical lithography, Optical simulations

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As the push for improved resolution in wafer lithography intensifies and 0.18 micrometer devices are nearing production, the potential impact of subhalf micron reticle defects has become a growing concern. There have been several studies on the printability of subhalf-micron defects on high resolution reduction photolithography equipment. These studies have been extended to 1X lithography systems and more recently to advanced sub-micron 1X steppers. Previous studies have indicated that 0.20 micrometer opaque and 0.25 micrometer clear pinhole defects were at the margins of adversely impacting 0.65 micrometer lithography on a 1X stepper. However, due to the limited number of defects at these sizes on the reticle, definitive conclusions on printability could not be drawn. An additional study, using a three dimensional (3D) optical lithography simulation program, has shown defect size, proximity to an adjacent feature, and feature pitch to be significant factors contributing to reticle defect printability. Using the simulation findings as a guide, a new reticle was designed to contain an increased number of clear pinhole and opaque defects in the 0.15 to 0.30 micrometer range located in multiple pitches of both horizontal and vertical line/space pairs. Defect printability was determined using a 1X i-line projection stepper with focus and exposure optimized for nominal critical dimensions of 0.65 micrometer. The reticle and wafer defects were measured using low voltage SEM metrology. Simulation and experimental results have shown that pitch is the most significant contributor in the printability of clear pinhole, opaque, square and aspect ratio defects. In general, the impact of defect proximity to an adjacent feature is less extreme than the effect of pitch, but is more pronounced for clear pinhole defects. This study suggests that simulation can be a useful tool to help lithographers understand the behavior of reticle defects for particular layout design parameters. Consequently, simulation can be used to develop realistic reticle defect specifications with mask vendors, and improve cost-effectiveness. Defect printability simulation can also be used to predict the effect of known defects on existing reticles to determine if these reticles should be used for manufacturing.

Proceedings Article | 27 December 1996 Paper

Subhalf-micron mask defect detectability and printability at 1X reticle magnification

Dan Schurz, Warren Flack, Gary Newman

Proceedings Volume 2884, (1996) https://doi.org/10.1117/12.262801

KEYWORDS: Reticles, Semiconducting wafers, Computer aided design, Inspection, Opacity, Manufacturing, Scanning electron microscopy, Lithography, Photomasks, Defect detection

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Proceedings Article | 7 June 1996 Paper

Investigation of the properties of photosensitive polyimide films

Warren Flack, Gary Flores, Lorna Christensen, Gary Newman

Proceedings Volume 2726, (1996) https://doi.org/10.1117/12.240970

KEYWORDS: Lithography, Semiconducting wafers, Photoresist materials, Manufacturing, Chemistry, Scanning electron microscopy, Optical lithography, Photoresist developing, Critical dimension metrology, Process modeling

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Modem package designs generate a large amount of stress on the die which can be controlled using a thick film of polyimide over the passivation layer. Polyimide film thicknesses in excess of twenty microns at exposure are becoming common for very thin packages. The standard polyimide lithographic process frequently utilizes a trilayer film consisting of an adhesion layer, a polyimide film, and photoresist. A major advance in polyimide technology occurred with the introduction of photosensitive polyimide materials. These materials reduce the total number of process steps in the polyimide process. They also offer the opportunity to combine the passivation and polyimide lithography steps into one process level resulting in significant process simplification and manufacturing cost reduction. Consequently, there is a rapid increase in the use of photosensitive polyimides in the semiconductor industry. There are a number of important issues associated with photosensitive polyimide processing. Because most photosensitive polyimides are negative tone, residual film formation has a major impact on resolution and the usable process window. The high exposure doses required for thicker polyimide films exacerbates the residual film problem. Also, resolving small features such as fuse windows in DRAMs is frequently required in thick photosensitive polyimide layers. These small features result in polyimide height-to-linewidth aspect ratios that are comparable to many photoresist applications. Because of these requirements, photosensitive polyimide applications could benefit from detailed process characterization to enhance resolution and increase process latitude. Unfortunately, there is scant literature pertaining to lithographic performance and lithographic process modeling for photosensitive polyimide films. An extension of basic photoresist characterization techniques for thin films can be applied to thick photosensitive polyimide processes. The develop rate characteristics and lithographic performance for several commercial photosensitive polyimide products were studied at a thickness of 12 microns. Cross sectional SEM analysis, Bossung plots, and film retention plots are used to establish relative lithographic capabilities. These experimental results are used to study the effects of polyimide physical and chemical properties on lithographic performance.

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