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LITHOGRAPHY SYSTEM, SENSOR, CONVERTER ELEMENT AND METHOD OF MANUFACTURE

IP.com Disclosure Number: IPCOM000201728D
Publication Date: 2010-Nov-19

Publishing Venue

The IP.com Prior Art Database

Abstract

Charged particle beamlet lithography system for transferring a pattern to a surface of a target comprising a sensor for determining one or more characteristics of one or more charged particle beamlets. The sensor comprises a converter element for receiving charged particles and generating photons in response. The converter element comprises a surface for receiving one or more charged particle beamlets, the surface being provided with one or more cells for evaluating one or more individual beamlets. Each cell comprises a predetermined blocking pattern of one or more charged particle blocking structures forming multiple knife edges at transitions between blocking and non-blocking regions along a predetermined beamlet scan trajectory over the converter element surface. The converter element surface is covered with a coating layer substantially permeable for said charged particles and substantially impermeable for ambient light. An electrically conductive layer is located between the coating layer and the blocking structures.

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LITHOGRAPHY SYSTEM, SENSOR, CONVERTER ELEMENT AND METHOD OF MANUFACTURE

BACKGROUND OF THE INVENTION
1. Field of the Invention

    The present invention relates to a charged particle lithography system, in particular to a maskless charged particle system, to a sensor therefore, in particular for determining charged particle beam properties, to a converter element therefore, as well as to a method of manufacturing the same.
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2. Description of the Related Art


Charged-particle beamlet lithography systems make use of a plurality of charged particle beamlets to transfer a pattern onto the surface of a target. The beamlets may write the pattern by being scanned over the target surface while their trajectory may be controllably blocked so as to create a beamlet that can be turned on or off. Blocking may be established

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by electrostatic deflection of beamlets on a blocking surface. Additionally, or alternatively, the size and shape of the beamlets may be adapted along the trajectory. Deflection, shaping and/or size adaptation may be executed by one or more electron optical components like for example an aperture array, an array of electrostatic deflectors and/or beamlet blankers.

In order to transfer a pattern onto the target surface, the controllable blocking of beamlets

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in combination with their movement over the target surface is performed in accordance with modulation information. An example of a multiple charged-particle beamlet lithography system is described in U.S. patent no. 6,958,804, which disclosure is herewith incorporated by reference in its entirety.

Such lithography systems can have very large numbers of beamlets, i.e. in the order

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of 10,000 or higher, for example 13,000. Future designs even envisage numbers in the order of 1,000,000 beamlets. It is a general aim for current electron beam lithography systems to be able to pattern a target surface in high-resolution, with some applications being capable of imaging patterns with a critical dimension of well below 100 nm feature sizes.

DM_EU:9939555_1

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    For such multiple beamlet, high-resolution lithography systems to be commercially viable it is important that the position of each one of the charged particle beamlets is precisely known and controlled. Additionally, knowledge and control of spot size and shape and intensity of the beamlets at the target surface are also of importance. Due to various circumstances, such as manufacturing tolerances and thermal drift, such beamlet

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characteristics may however deviate from their expected and desired characteristics, which may render these deviating beamlets invalid for accurate patterning.

    Such deviations may include, among other things, a deviation in position, a deviation in spot size as exposed on the target surface and/or a deviation in beamlet intensity. Deviating beamlets may severely affect the quality of the pattern to be written. It

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is therefore desirable to detect these deviations so that corre...