International Business Machines Corporation

Other

Burn J Lin

Constantino Lapadula

Thomas J Cardinali

Lars W Liebmann

Alan Edward Rosenbluth

Michael Hatzakis

Janusz S Wilczynski

Donald J Samuels

Frank Benjamin Kaufman

Yuan Taur

Yeong S Lin

Mark O Neisser

Bea-Jane L Yang

Steven R Kramer

Vivian W Chao

Anne M Moruzzi

Jer-Mind Yang

John Sebastian Mentesana

William Godfrey Santy

A method and apparatus for correcting defects in a phase shift mask to be used in photolithography. More specifically, the method of the invention includes creating a second repair mask which contains phase shifters. Regions surrounding the defects on the first mask are made opaque. The design circuitry located in these defective regions is copied onto the second mask. During a second exposure the design circuitry is placed onto the semiconductor wafer. Therefore, this method and apparatus provides an inexpensive solution to a difficult problem.

Simple repair method for phase shifting masks

A multi-station Step and Repeat Apparatus (Stepper) for imaging semiconductor wafers. The stepper has at least 2 stations, at least one of which is for imaging. The second station may be used for image field characterization, or image defect correction, or for Phase Shift Mask (PSM) loop cutting. Multiple laser beams directed in orthogonal directions provide interferometric monitoring to track wafer locations for wafers on the stepper.

Step and repeat apparatus having enhanced accuracy and increased

A minimal amount of waste in liquid resist material is achieved by dispensing through small openings at close proximity to the substrate. An airtight substrate chamber as well as airtight sealing of dispensing assembly and airtight sealing of the space that does not have to be opened for substrate loading and unloading, are used to facilitate a uniform and planarized coating after a high-speed spin off of excess resist.

Proximity-dispensing high-throughput low-consumption resist coating

A structure and fabrication method for a phase-shifting lithographic mask wherein an attenuated phase-shifting mesh structure (Att PSM) is combined with an alternating-element phase shifting mask (Alt PSM) to provide a mask combination consisting of phase-shifted and unshifted attenuated backgrounds in which the phase-shifted attenuated backgrounds surrounds the unshifted components and the unshifted attenuated background surrounds the phase-shifted components.

Combined attenuated-alternating phase shifting mask structure and

A photolithographic technique and apparatus involving two exposures and the sectioning of a first original mask opening that has segments which conflict with a second original mask opening. A plurality of segmented openings are configured in a first mask including at least one phase shifted opening and at least one non-phase shifted opening. Imaging radiation is projected through the plurality of segmented openings onto at least two electromagnetic radiation application regions (EARs) on a surface to be imaged during one exposure, with one of the two EAR's being phase shifted and the other non-phase shifted. At least one segmented opening is formed in a second mask. Radiation is projected through the second mask segmented opening onto one or more EARs on the surface during another exposure. At least one of the second mask EARs interconnects at least one of the phase shifted EARs and one of the non-phase shifted EARs. The first mask is a split mask, the second mask is a cover mask and both masks may be on a single mask substrate.

Split and cover technique for phase shifting photolithography

A structure and fabrication method for an alternating-element phase-shifting mask (Alt PSM) wherein all the mask pattern components extending in a first direction, such as the x direction are formed on a first mask substrate and all the mask pattern components extending in a second direction orthogonal to the first direction, such as the y direction, are formed on a second mask substrate. The two mask substrates are either combined together in a single mask for a single exposure step on a wafer, or separate exposures may be made through each mask and superimposed on a single wafer.

Orthogonally separated phase shifted and unphase shifted mask patterns

Spin coating of resist on a semiconductor wafer is done in a controlled chamber, starting with introducing a resist solvent vapor into the chamber from a nozzle or an adjacent chamber, applying the resist by spraying a very thin layer of the resist material and then removing solvent from the chamber. The result is a saving in resist material and enhanced coating uniformity.

Material-saving resist spinner and process

A phase-contrast microscope with a quarter-wave plate in a pupil plane with a thickness of .lambda..theta./2.pi. is provided for the inspection of a phase-shifting mask. The angle .theta. and the wavelength .lambda. are adjustable to optimize the phase detection sensitivity. A similar .theta. and .lambda. optimization scheme is applied to an interference microscope assembly wherein an inspection beam is split into two beams by a beam splitter to be reflected by mirrors and then recombined at a second beam splitter. A mirror in one of the beams can be moved to change .theta. to its optimum value at a given .lambda. which can be changed by light source selection or by filter change.

Method of inspecting phase shift masks employing phase-error enhancing

A phase-shifting mask consisting of phase shifting rim surrounding every pattern. The 0.degree. and 180.degree. areas defined by a straightforward rim phase-shifting mask are reversed alternately for closely packed patterns. This reversal can take the form of 0.degree. to 180.degree. and 180.degree. to 0.degree. as well as the form of 0.degree. to 180.degree. and 0.degree. to -180.degree. . For small opaque lines, the rim phase shifter may become the only picture element, leaving no mask absorber pattern inside the rim. Individual or uniform pattern sizing can be used to ensure a large common exposure-defocus window. Various fabrication techniques requiring or not requiring a second aligned exposure during mask fabrication, combining with several different forms of mask substrate are also described.

Alternating rim phase-shifting mask

Spin coating of resist on a semiconductor wafer is done in a controlled chamber, starting with introducing a resist solvent vapor into the chamber from a nozzle, applying the resist by spraying a very thin layer of the resist material, monitoring and adjusting the resist thickness during spinning in vapor, and then removing solvent from the chamber. The result is a saving in resist material and enhanced coating uniformity.

In situ resist control during spray and spin in vapor

Feature biassing applied to phase shifting masks is used to improve the exposure latitude and depth of focus of an optical projection imaging system. Making the phase shifters absorptive facilitates a phase shifting mask system for arbitrary layouts. Combining phase shifters of different levels of absorption further enhance the improvements. Even more enhancement can be gained by combining biassing with absorption levels.

Feature biassing and absorptive phase-shifting techniques to improve

A phase-shifting mask is composed of material including a substrate carrying a first phase-shifting layer having a phase-shift of .THETA., a second phase-shifting layer stacked upon the first layer having a phase-shift of (2.pi.-.THETA.), and a third phase-shifting layer stacked upon the second layer next with a phase-shift of .THETA.. Missing phase-shifters, unwanted phase-shifters, or defects in the transparent films are repaired by removing one or two layers depending upon whether the phase-shifting status has to be retained or altered. In one alternative a large etch selectivity exists between the first, second and third layers, or else a lack of etch selectivity is complemented with etch stop layers embedded between the phase-shifting layers as follows: a) if an defect is found in a phase-shifted area and the defect must be removed without turning the phase-shifted area into a non-phase-shifted area, then two successive layers in the phase-shifted area are removed; b) if an error is found in a non-phase-shift area, then the mask can be repaired in the area surrounding the error by removing the layer in the area to make the area a phase-shifted area; c) if a defect is found in a non-phase-shifted area and the defect must be removed without turning the phase-shifted area into a phase-shifted area, then two successive layers in the non-phase-shifted area are removed.

Mask-structure and process to repair missing or unwanted phase-shifting

A lithographic process having improved image quality by employing a mask that includes a plurality of opaque elements or transparent elements that are smaller than the resolution of the lighography to be employed in order to control the transmittance of the actinic light exposure area.

Lithographic process having improved image quality

A patterned image including on a substrate, a patterned image of a first resist polymeric material and patterned image of a second and different resist material on the first resist polymeric material. The polymeric material contains reactive hydrogen functional groups and/or reactive hydrogen precursor groups. At least the surface layer of the delineated and uncovered first resist polymer material is reacted with a multifunctional organometallic material containing at least two functional groups that are reactive with the functional groups of the polymeric material.

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Tampa, FL, United States of America

Burn J Lin