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Showing papers on "Mask inspection published in 1999"


Proceedings ArticleDOI
14 Jun 1999
TL;DR: In this paper, a DUV 4X reduction stepper was used to print a reticle with programmed defects across an exposure/focus matrix, with the minimum feature size being 200 nm.
Abstract: As semiconductor processes have moved towards lower k 1 and mask inspection equipment has moved into the UV range, more subtle reticle defects have been found to cause manufacturing problems. Lower k 1 and new lithography processes and reticle technologies, such as OPC and PSM, have made it difficult to determine the significant and these defects. This paper reports on the development of a simulation tool that will improve the yield and productivity of photomask manufacturers and wafer manufacturers by improving reticle defect assessment. This study demonstrates the accuracy of simulation software that predicts resist patterns based on sophisticated modeling software that uses optical images obtained from a state-of-the-art UV optical inspection system. A DUV 4X reduction stepper was used to print a reticle with programmed defects across an exposure/focus matrix, with the minimum feature size being 200 nm. Quantitative comparisons between predicted and measured wafer CDs were made. In summary, it was found that the simulation software based solely on aerial images predicted absolute CDs with limited accuracy, but differential CDs with limited accuracy, but differential CDs, obtained by utilizing both the reference and defect images, were predicted accurately. Comparison of simulations using both reticle SEM images and optical reticle inspection images showed good agreement, demonstrating the accuracy and high resolution of the optical reticle inspection images. Application of differential aerial images to a simple test case showed that it was possible to identify and therefore eliminate a significant number of defects that did not print, thereby improving defect assessment.

51 citations


Patent
27 May 1999
TL;DR: In this paper, a method for determining whether a defect that is detected by photomask inspection will adversely affect a semiconductor device, such as a wafer, is proposed, which has the ability of relating defect specifications directly to device performance and wafer yields and assessing the impact of combining the defect with the critical dimension error using standard inspection tools.
Abstract: A method for determining whether a defect that is detected by photomask inspection will adversely affect a semiconductor device, such as a wafer. The method has the ability of relating defect specifications directly to device performance and wafer yields, and assessing the impact of combining the defect with the critical dimension error using standard inspection tools. More specifically, the method includes the steps of: inspecting the photomask for defects; measuring the size and location of the defects relative to features on the photomask; classifying the defects by type of defect; assigning an equivalent mask critical dimension error (EME) value to each of the features based on size, location and type of defect; assigning a total mask error to each of the features by adding EME values to each defect impacting the features; and comparing the equivalent critical dimension error to a mask critical dimension error tolerance to determine whether the defects adversely affect the performance of the semiconductor device.

45 citations


Patent
Koji Hashimoto1, Shigeki Nojima1
02 Sep 1999
TL;DR: In this article, an exposure mask inspecting method for use in manufacturing semiconductor devices is presented, which calculates the gradients of a correlation curve of a variation in critical dimension of an exposure masks and a variation of critical dimensions of a resist.
Abstract: Disclosed is an exposure mask inspecting method for use in manufacturing semiconductor devices This inspecting method calculate gradients of a correlation curve of a variation in critical dimension of an exposure mask and a variation in critical dimension of a resist, extracts portions having large slopes of the correlation curve, and slopes the portions having large slopes of the correlation curve as to-be-measured portions at the time of verifying the specifications of the surface critical dimension of the exposure mask

32 citations


Proceedings ArticleDOI
26 Jul 1999
TL;DR: In this article, IBM's Semiconductor Research and Development Center and Mask Manufacturing and Development facility demonstrated an important milestone toward integration of alternating phase shifted masks into the manufacturing process by demonstrating an automated design solution and yielding a functional alternating phase shift mask.
Abstract: While the benefits of alternating phase shifted masks in improving lithographic process windows at increased resolution are well known throughout the lithography community, broad implementation of this potentially powerful technique has been slow due to the inherent complexity of the layout design and mask manufacturing process. This paper will review a project undertaken at IBM's Semiconductor Research and Development Center and Mask Manufacturing and Development facility to understand the technical and logistical issues associated with the application of alternating phase shifted mask technology to the gate level of a full microprocessor chip. The work presented here depicts an important milestone toward integration of alternating phase shifted masks into the manufacturing process by demonstrating an automated design solution and yielding a functional alternating phase shifted mask. The design conversion of the microprocessor gate level to a conjugate twin shifter alternating phase shift layout was accomplished with IBM's internal design system that automatically scaled the design, added required phase regions, and resolved phase conflicts. The subsequent fabrication of a nearly defect free phase shifted mask, as verified by SEM based die to die inspection, highlights the maturity of the alternating phase shifted mask manufacturing process in IBM's internal mask facility. Well defined and recognized challenges in mask inspection and repair remain and the layout of alternating phase shifted masks present a design and data preparation overhead, but the data presented here demonstrate the feasibility of designing and building manufacturing quality alternating phase shifted masks for the gate level of a microprocessor.

31 citations


Patent
Kazuya Kamon1
26 May 1999
TL;DR: In this paper, a photomask fabrication method has a transparent substrate (10), a shade pattern (11 ), a phase shift pattern ( 102 ), and a shield pattern (101) having a flat surface that is selectively formed on the transparent substrate and shield pattern.
Abstract: A photomask fabricated by a photomask fabrication method has a transparent substrate ( 10 ), a shade pattern ( 11 ) formed in a hollow section ( 23 ), and a phase shift pattern ( 102 ) having a flat surface that is selectively formed on the transparent substrate ( 10 ) and the shield pattern ( 11 ).

9 citations


Patent
Qi-De Qian1, Edita Tejnil1, Giang T. Dao1
30 Dec 1999
TL;DR: In this paper, a method is described that involves accepting a mask design file input and then simulating the inspection of a mask through an optical channel, which corresponds to a mask inspection tool optical channel.
Abstract: A method is described that involves accepting a mask design file input and then simulating the inspection of a mask through an optical channel. The mask design file has patterns. The optical channel corresponds to a mask inspection tool optical channel. The mask is patterned according to the mask design file patterns.

8 citations


Proceedings ArticleDOI
Edita Tejnil1, Alan R. Stivers1
30 Dec 1999
TL;DR: In this paper, the overall defect sensitivity requirements and scaling trends in inspection of patterned masks are discussed, and the data acquisition rates of several hundred megapixels/sec required during inspection of 0.07-micrometer technology masks and to maintain light intensities below the damage threshold of mask materials are discussed.
Abstract: The final qualification of masks for extreme ultraviolet (EUV) lithography may require defect inspection utilizing EUV radiation. To properly address inspection of masks for the 0.07-micrometer technology generation targeted by EUV lithography, the overall defect sensitivity requirements and scaling trends in inspection of patterned masks are discussed. To achieve the data acquisition rates of several hundred megapixels/sec required during inspection of 0.07-micrometer technology masks and to maintain light intensities below the damage threshold of mask materials, simultaneous acquisition of the inspection signal from multiple pixels on the mask, rather than the serial pixel data collection currently used in many mask inspection tools, will become necessary. The high data rates needed for future mask inspection technologies impose requirements on the minimum pulse repetition rate of the light source used in the inspection and influence the EUV mask inspection system design options. EUV light sources that either produce continuous-wave radiation or operate at pulse repetition rates of at least 10 - 100 kHz will be needed for mask inspection relevant to EUV technology, assuming that data from 104 or more pixels can be measured in parallel. The average EUV light source power requirements for an at- wavelength, bright-field EUV mask inspection system are estimated to be on the order of 1 W. The basic technologies for sources, optics, and detectors needed for at-wavelength EUV mask inspection currently exist but significant efforts to develop the numerous system components would be necessary to implement practical EUV mask inspection tools.

8 citations


Patent
30 Jul 1999
TL;DR: In this article, the authors proposed a method to make a mask preparation device which sufficiently copes with the quality requirement for a mask and to efficiently prepare the mask by obtaining such constitution that the mask can be received and delivered between a mask carriage and a mask washing part and between the mask washing and inspection and correction part on a condition that a mask surface is inclined by a prescribed angle.
Abstract: PROBLEM TO BE SOLVED: To make a mask preparation device which sufficiently copes with the quality requirement for a mask and to efficiently prepare the mask by obtaining such constitution that the mask can be received and delivered between a mask carriage and a mask washing part and between the mask washing part and a mask inspection and correction part on a condition that a mask surface is inclined by a prescribed angle. SOLUTION: By the mask carriage 120, the mask 180 is received from a normal mask storage case 110 on the condition that the mask surface is almost vertically set and delivered to the mask washing part 130. By the washing part 130, the processed mask 180 is delivered to the mask inspection and correction part 140 on the condition that the angle θ1 of the mask surface is kept as it is. The mask 180 is washed by the washing part 130 and inspected and corrected by the correction part 140. However, the mask 180 can be received and delivered between the respective parts through a rotating roll or a roller on the condition that the respective parts are closely located with each other. Thus, workability is made excellent and the falling accident of the mask 180 is prevented from occurring when the mask is received and delivered.

8 citations


Proceedings ArticleDOI
Huitzu Lin1, John Lin1, Ching Siun Chiu1, Ying-Ying Wang1, Anthony Yen1 
30 Dec 1999
TL;DR: In this paper, the authors discuss items that concern both photolithographers and mask-makers as assisting features are applied in manufacturing, including mask error factor (MEF), depth of focus (DOF) improvement, AF line width control, lithographic impact caused by the drift of the mean value of mask CD, defect printability in resist, and defect sensitivity during mask inspection.
Abstract: The downscaling of critical dimensions (CD) in semiconductor circuits has been pushing photolithography to print features below the wavelength of the light source. However, severe proximity effect and small DOF for isolated lines have brought challenges to sub-0.18 micrometer lithography in manufacturing using 248 nm scanners. To improve proximity effect and DOF for isolated lines, assisting features (AF) on masks are considered. However, the practical application of this technique has been limited because of difficulties in mask fabrication. In this paper, we discuss items that concern both photolithographers and mask-makers as AF is applied in manufacturing. These items include mask error factor (MEF), depth of focus (DOF) improvement, AF line width control, lithographic impact caused by the drift of the mean value of mask CD, defect printability in resist, and defect sensitivity during mask inspection.

5 citations


Proceedings ArticleDOI
30 Dec 1999
TL;DR: In this paper, a next generation mask inspection system MC-3000 which used DUV optics has been developed, in order to perform mask inspection with the high reliability for 150 nm-rule and below devices, the inspection system with high resolution is indispensable.
Abstract: In order to perform mask inspection with the high reliability for 150 nm-rule and below devices, the inspection system with high resolution is indispensable. The phase shift masks like DUV HT masks must also be inspected with high sensitivity. A next generation mask inspection system MC-3000 which used DUV optics has been developed, in order to achieve these requirement. The wavelength of this optics is 257 nm that is shorter than that of current UV inspection systems, and is nearly equal to that of current DUV lithography systems. Short wavelength light and high NA optics obtain high resolution, so the defect detection of 130 nm or less is attained. The special issues for the DUV optics were solved by several new techniques. This paper reports the system configuration, basic characteristics for defect detection and inspection performances.

4 citations


Journal ArticleDOI
06 Jul 1999
TL;DR: In this article, a programmable X-ray mask with various defects such as dimension error, position shift and absorber defect sizes for typical patterns of lines-and-spaces, hole and 2-dimensional patterns is presented.
Abstract: Improvement in X-ray mask inspection system is essential for the realization of X-ray lithography. To evaluate the sensitivity of the present inspection system, we made a programmed X-ray mask, with various defects such as dimension error, position shift and absorber defect sizes for typical patterns of lines-and-spaces, hole and 2-dimension patterns. In this work, we evaluated the sensitivity of defect inspection system, and investigated the printability of the X-ray mask defects. Moreover, in order to specify the sensitivity of the next generation inspection system, we investigated the printability of the X-ray mask defects by using the X-ray lithographic simulator Toolset developed by University of Wisconsin. In this paper, we will present on defect inspectivity by using SEMSpec inspection system and the simulation.

Patent
11 Jan 1999
TL;DR: In this article, a photomask used in the formation of a mask read-only memory (mask ROM) device is provided, containing a bonding pad opening pattern and a code area opening pattern so that bonding pads and code areas are simultaneously formed in a more economical operation.
Abstract: A photomask used in a formation of a mask read only memory (mask ROM) device is provided. The photomask contains a bonding pad opening pattern and a code area opening pattern so that bonding pads and code areas are simultaneously formed in a more economical operation.

Patent
31 Aug 1999
TL;DR: In this paper, a mask which can be precisely controlled by storing the large amount of information required for the mask and the control device thereof is provided with the mask 1 having an IC 2 for reading and writing mask information which can write and read mask information and a signal conductor pattern 3 connected to the IC 2 and constituted of conductive Cr thin-film metal formed on the mask.
Abstract: PROBLEM TO BE SOLVED: To provide a mask which can be precisely controlled by storing the large amount of information required for the mask and the control device thereof SOLUTION: This control device is provided with the mask 1 having an IC 2 for reading and writing mask information which can write and read mask information and a signal conductor pattern 3 for reading and writing mask information connected to the IC 2 and constituted of conductive Cr thin-film metal formed on the mask 1 and a mask information read and write device 5 connected to the pattern 3 Thus, the erroneous mask is prevented from being used by storing not only the drawing number of the mask, the name of an owner and the calendar of a manufacturing time and the like but also the information such as the blanks drawing number, the inspecting condition, the inspection result, the propriety of the correction, the position, the pellicle drawing number, the washing condition, the washing frequency and the phase difference and the like of the mask as the information of the manufacturing time and confirming them before the mask is used Besides, the mask inspection result of this time can be easily compared with the last result at a periodical inspecting time after it is used

Patent
29 Nov 1999
TL;DR: In this paper, the authors proposed a mask inspection device and mask inspection method capable of inspecting a mask with an electron beam exposure device and making the installation of an independent inspection device unnecessary.
Abstract: PROBLEM TO BE SOLVED: To provide a mask inspection device and mask inspection method capable of inspecting a mask with an electron beam exposure device and making the installation of an independent inspection device unnecessary. SOLUTION: In an electron beam exposure device 1 having an electron gun 11 for emitting election beams EB, an irradiating optical system 12 for irradiating electron beams emitted to the mask M, and an image forming optical system 16 for forming an image of the electron beams passed through the mask M on a wafer W, an electron detector 20 that can be mounted/demounted with a loafing mechanism 21 and detecting the electron beams passed through the mask M when mounted, and a computer 30 for inspecting the defects of the mask M based on the electron beans detected with the electron detector 20, are installed in the position directly below the mask M. Independent installation of the mask inspection device is made unnecessary, the facility space in the manufacturing plant of a semiconductor device is reduced, and the cost for the device as a whole for manufacturing the semiconductor device is also reduced. COPYRIGHT: (C)2001,JPO