Optical imaging device with image defect determination

Patent metadata

Field	Value
Publication number	US-9235131-B2
Application number	US-201314027776-A
Country	US
Kind code	B2
Filing date	Sep 16, 2013
Priority date	Jul 1, 2008
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

An optical imaging device, including an imaging unit and a measuring device. The imaging unit includes a first optical element group having at least one first optical element, which contributes to the imaging. The measuring device determines an imaging error, which occurs during the imaging, using a capturing signal. The measuring device includes a measurement light source, a second optical element group and a capturing unit. The measurement light source emits at least one measurement light bundle, The second optical element group includes an optical reference element and a second optical element, which guide the measurement light bundle onto the capturing unit, to generate the capturing signal. Each second optical element has a defined spatial relationship with a respective one of the first optical elements, The second optical elements differ from the first optical elements. The measuring device determines the imaging error with the capturing signal.

First claim

The invention claimed is:

1. Optical imaging device, comprising:
an imaging unit adapted to image an object point on an image point and
a measuring device, wherein:
the imaging unit comprises a first optical element group having at least one first optical element, which is adapted to contribute to the imaging of the object point on the image point,
the measuring device is adapted to determine at least one imaging error, which occurs when imaging the object point on the image point, using at least one capturing signal,
the measuring device comprises at least one measurement light source, a second optical element group and at least one capturing unit,
the measurement light source emits at least one measurement light bundle,
the second optical element group comprises at least one optical reference element and at least one second optical element, which are adapted to guide the at least one measurement light bundle onto the at least one capturing unit in order to generate the at least one capturing signal,
each second optical element has a defined spatial relationship with a respective one of the first optical elements, and at least one of the second optical elements differs from the first optical elements, and
the measuring device is adapted to determine the at least one imaging error with the at least one capturing signal.

2. Optical imaging device according to claim 1 , wherein
the at least one of the second optical elements is connected at least essentially rigidly to the respective first optical element.

3. Optical imaging device according to claim 1 , wherein
the at least one second optical element is connected to the respective first optical element via a gearing device, and
a defined movement transmission between a first movement of the first optical element in at least one first degree of freedom and a second movement of the second optical element in at least one second degree of freedom is predetermined by the gearing device.

4. Optical imaging device according to claim 1 , wherein at least one of:
the at least one first degree of freedom differs from the at least one second degree of freedom, and
the type of the at least one first degree of freedom is different from the type of the at least one second degree of freedom.

5. Optical imaging device according to claim 3 , wherein the gearing device has at least one element of an element group, the element group consisting of a flexural articulation, a leaf spring element and a lever element.

6. Optical imaging device according to claim 3 , wherein
the at least one imaging error has a first sensitivity with respect to the first movement,
the at least one capturing signal has a second sensitivity with respect to the second movement, and
the gearing device is adapted such that at least one of: (i) the second sensitivity corresponds at least to the first sensitivity and (ii) the second sensitivity is greater than the first sensitivity.

7. Optical imaging device according to claim 3 , wherein
a defined movement transmission between a third movement of the first optical element in at least one third degree of freedom and a fourth movement of the second optical element in at least one fourth degree of freedom is predetermined by the gearing device,
at least one of the gearing device and the second optical element is adapted such that the at least one capturing signal experiences a first change of a first type owing to the second movement, and the at least one capturing signal experiences a second change of a second type owing to the fourth movement, and
the first type is different from the second type.

8. Optical imaging device according to claim 1 , wherein at least one of:
at least one of the second optical elements is formed by one of the first optical elements,
at least one of the at least one measurement light source and the at least one capturing unit has a defined spatial relationship with at least one of the first optical elements, and
at least one of the at least one measurement light source and the at least one capturing unit is connected at least essentially rigidly or via a gearing device to one of the first optical elements.

9. Optical imaging device according to claim 1 , wherein at least one of:
at least one of the at least one measurement light source and the at least one capturing unit has a defined spatial relationship with a reference,
at least one of the at least one measurement light source and the at least one capturing unit is mechanically connected to the reference, and
the optical imaging device further comprises at least one reference capturing unit, which captures the spatial relationship between (i) at least one of the at least one measurement light source and the at least one capturing unit and (ii) the reference.

10. Optical imaging device according to claim 1 , further comprising:
a mask device for receiving a mask comprising a projection pattern, and a substrate device for receiving a substrate, wherein:
the first optical element group is adapted to image the projection pattern on the substrate,
the measuring device is adapted to determine an imaging error which occurs when imaging the projection pattern on the substrate as the at least one imaging error, and
at least one of at least one second optical element, the at least one measurement light source and the at least one capturing unit has a defined spatial relationship with the mask device or the substrate device.

11. Optical imaging device according to claim 10 , wherein at least one of:
at least one of the second optical element, the at least one measurement light source and the at least one capturing unit is connected at least essentially rigidly to the mask device or the substrate device,
at least one of the second optical element, the at least one measurement light source and the at least one capturing unit is fastened directly on the mask device or the substrate device, and
at least one of the second optical element, the at least one measurement light source and the at least one capturing unit is connected to the mask device or the substrate device via a gearing device, a defined movement transmission between a first movement of the mask device or the substrate device in at least one first degree of freedom and a second movement of at least one of the second optical element, the at least one measurement light source and the at least one capturing unit in at least one second degree of freedom is predetermined by a gearing device.

12. Optical imaging device according to claim 1 , wherein
the at least one measurement light source is a first measurement light source which emits at least one first measurement light bundle, and the at least one capturing unit is a first capturing unit which generates a first capturing signal,
the measuring device comprises at least one second measurement light source, a third optical element group and at least one second capturing unit,
the second measurement light source emits at least one second measurement light bundle,
the third optical element group comprises at least one third optical element, which is adapted to guide the at least one second measurement light bundle onto the at least one second capturing unit in order to generate at least one second capturing signal,
at least one of the third optical element, the at least one second measurement light source and the at least one second capturing unit has a defined spatial relationship with one of the first optical elements, and
the measuring device is adapted to determine the at least one imaging error by using the at least one second capturing signal.

13. Optical imaging device a

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Freimann Rolf
• Wegmann Ulrich

Classifications

• G03F7/706

  Aberration measurement · CPC title

• G01B9/02018

  Multipass interferometers, e.g. double-pass · CPC title

• G03F7/70 Primary

  Microphotolithographic exposure; Apparatus therefor (photo-masks G03F1/00) · CPC title

• G01B9/0209

  Low-coherence interferometers · CPC title

• G03F7/70491 Primary

  Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring processes · CPC title