A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Lithographic apparatus, and device manufacturing method

An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Method and apparatus for angular-resolved spectroscopic lithography characterization

The present invention is directed to methods for patterning a substrate by imprint lithography. Imprint lithography is a process in which a liquid is dispensed onto a substrate. A template is brought into contact with the liquid and the liquid is cured. The cured liquid includes an imprint of any patterns formed in the template. In one embodiment, the imprint process is designed to imprint only a portion of the substrate. The remainder of the substrate is imprinted by moving the template to a different portion of the template and repeating the imprint lithography process.

Step and repeat imprint lithography processes

An exposure apparatus for emitting exposure light onto a substrate via a projection optical system and a liquid to expose the substrate includes a supply pipe which supplies the liquid; a recovery pipe which recovers the liquid; a connection pipe which connects the supply pipe and the recovery pipe; and a switching device which switches a flow path of the liquid so that when liquid supply is stopped, the liquid that has flowed into the supply pipe flows to the recovery pipe via the connection pipe. The apparatus may further include a temperature regulation apparatus connected to the supply pipe, which performs temperature regulation of the liquid supplied to the supply pipe, and has a rough temperature regulator which roughly regulates the temperature of the liquid, and a fine temperature regulator which is arranged between the rough temperature regulator and the supply pipe and performs fine regulation of this temperature.

Exposure apparatus, and device manufacturing method

Described are imprint lithography templates, methods of forming and using the templates, and a template holder device. An imprint lithography template may include a body with a plurality of recesses on a surface of the body. The body may be of a material that is substantially transparent to activating light. At least a portion of the plurality of recesses may define features having a feature size less than about 250 nm. A template may be formed by obtaining a material that is substantially transparent to activating light and forming a plurality or recesses on a surface of the template. In some embodiments, a template may further include at least one alignment mark. In some embodiments, a template may further include a gap sensing area. An imprint lithography template may be used to form an imprinted layer in a light curable liquid disposed on a substrate. During use, the template may be disposed within a template holder. The template holder may include a body with an opening configured to receive the template, a support plate, and at least one piezo actuator coupled to the body. The piezo actuator may be configured to alter a physical dimension of the template during use.

Template for room temperature, low pressure micro- and nano-imprint lithography

A method and system of interference lithography (also known as interferometric lithography or holographic lithography) which utilizes phase-locked, scanning beams (so-called scanning beam interference lithography, or SBIL). The invention utilizes a high-precision stage (30) that moves a substrate (17) under overlapped and interfering pairs of coherent beams. The overlapped beams interfere, generating fringes, which form a pattern 'brush' for subsequent writing of periodic and quasi-periodic patterns on the substrate. The phase of the fringes in the overlapped region is phase-locked to the motion of the precision stage. The invention includes methods for forming, overlapping, and phase-locking interfering pairs of beams on a variety of substrates; methods for measuring and controlling the period, phase, and angular orientation of fringes generated by the overlapping beams; and methods for measuring and controlling the effects of stage mechanical and thermal drift and other disturbances during the writing process.

Interference lithography utilizing phase-locked scanning beams

A method and system of interference lithography (also known as interferometric lithography or holographic lithography) which utilizes phase-locked, scanning beams (so-called scanning beam interference lithography, or SBIL). The invention utilizes a high-precision stage that moves a substrate under overlapped and interfering pairs of coherent beams. The overlapped beams interfere, generating fringes, which form a pattern “brush” for subsequent writing of periodic and quasi-periodic patterns on the substrate. The phase of the fringes in the overlapped region is phase-locked to the motion of the precision stage. The invention includes methods for forming, overlapping, and phase-locking interfering pairs of beams on a variety of substrates; methods for measuring and controlling the period, phase, and angular orientation of fringes generated by the overlapping beams; and methods for measuring and controlling the effects of stage mechanical and thermal drift and other disturbances during the writing process.

Method and system for interference lithography utilizing phase-locked scanning beams

Pattern-placementmetrology plays a critical role in nanofabrication. Not far in the future, metrology standards approaching 0.2 nm in accuracy will be required to facilitate the production of 25 nm semiconductor devices. They will also be needed to support the manufacturing of high-density wavelength-division-multiplexed integrated optoelectronicdevices. We are developing a new approach to metrology in the sub-100 nm domain that is based on using phase-coherent fiducial gratings and grids patterned by interference lithography. This approach is complementary to the traditional mark-detection, or “market plot” pattern-placementmetrology. In this article we explore the limitations of laser-interferometer-based mark-detection metrology, and contrast this with ways that fiducial grids could be used to solve a variety of metrology problems. These include measuring process-induced distortions in substrates; measuring patterning distortions in pattern-mastering systems, such as laser and e-beam writers; and measuring field distortions and alignment errors in steppers and scanners. We describe a proposed standard for pattern-placementmetrology, which includes both a fiducial grid and market-type marks. Finally, a number of methods through which phase-coherent periodic structures can be patterned are shown, including “traditional” interference lithography, achromatic interference lithography, near-field interference lithography, and scanning-beam interference lithography.

Sub-100 nm metrology using interferometrically produced fiducials

Alignment marks on first and second plates include a plurality of periodic gratings A grating on a first plate has a period or pitch p1 paired up with a grating on the second plate that has a slightly different period p2 A grating on the first plate having a period p3 is paired up with a grating on the second plate having a slightly different period p4 Illuminating the gratings produces a first interference pattern characterized by a first interference phase where beams diffracted from the first and second gratings overlap and a second interference pattern characterized by a second interference phase where beams diffracted from the third and fourth gratings overlap The plates are moved until the difference between the first and second interference phases correspond to a predetermined interference phase difference Further invention uses an interrupted-grating pattern on the second plate with certain advantages Further advantages are obtained using a checkerboard pattern on the second plate In addition two inventions are made for measuring gap One method uses the same marks on the second plate as used in aligning, and the second uses no marks on the second plate, which is an advantage in some cases

Optical interference alignment and gapping apparatus

An apparatus and method of measuring the gap between one substantially planar object, such as a mask, and a second planar object, such as a substrate. The invention achieves a high degree of sensitivity, accuracy, capture range, and reliability, through a novel design of a mark located only on the mask-plate. The light is inclined to the surfaces so associated optical components do not interrupt the exposing beam used in lithography. The same optics are used as for aligning overlay. Each gapping mark on the mask-plate includes one or more two-dimensional gratings (1441, 1442), each with period constant in the incident plane, but varying in the transverse plane as shown in the enlargements (1443, 1444). When illuminated, two images are formed of each of the two-dimensional gratings, with fringes resulting from interference between paths having traveled different distances through the gap and the mask-plate as a result of successive diffractions and reflections. Phase and geometric measurements from these images yield accurate measurement of the gap between the plates. Direct calibration, referenced to the light-wavelength, is obtained from a diffractive Michelson technique that uses a linear grating also included within the gapping mark.

Patrick N. Everett

Papers

Interference lithography utilizing phase-locked scanning beams

Method and system for interference lithography utilizing phase-locked scanning beams

Sub-100 nm metrology using interferometrically produced fiducials

Optical interference alignment and gapping apparatus

Optical gap measuring apparatus and method using two-dimensional grating mark with chirp in one direction