JPWO2021113273A5

JPWO2021113273A5 -

Info

Publication number: JPWO2021113273A5
Application number: JP2022532673A
Authority: JP
Publication date: 2023-09-12
Anticipated expiration: 2040-12-01

Claims

a light source that generates a beam of light;
objective system and
a chuck configured to hold a wafer in the path of the light beam through the objective;
a relay lens disposed on the path of the light beam and between the light source and the objective system;
a tunable illumination aperture disposed on the path of the light beam and between the light source and the relay lens;
a first tube lens disposed on the path of the light beam between the relay lens and the objective system;
a first movable focus lens disposed on the path of the light beam between the first tube lens and the relay lens;
a 2D imaging camera configured to receive light reflected from the wafer via the objective system;
a second movable focus lens disposed on the path of the light beam and between the objective system and the 2D imaging camera;
a second tube lens disposed on the path of the light beam between the second movable focus lens and the objective system;
Equipped with
The first movable focus lens and the second movable focus lens control the path of the light beam to adjust the illumination complex between the light source and the wafer and the focusing complex between the wafer and the 2D imaging camera. the first movable focus lens and the second movable focus lens are configured to position the illumination focus at, above or below the surface of the wafer;
The system wherein the 2D imaging camera is configured to generate a gray field image of the wafer.

2. The system of claim 1, further comprising a structured mask disposed on the path of the light beam between the light source and the objective, the plurality of apertures through which the light beam passes through the structure. a structured mask, wherein a portion of the light beam is blocked by the structured mask.

3. The system of claim 2, wherein the structured mask is located between the light source and the first movable focusing lens.

4. The system of claim 3, wherein the structured mask is located between the relay lens and the first movable focus lens.

3. The system of claim 2, wherein the structured mask is configured to be oblique with respect to the path of the light beam.

The system of claim 1, wherein the system has an illumination numerical aperture of 0 to 0.9.

2. The system of claim 1, wherein the system has a collection path numerical aperture of at least 0.9.

2. The system of claim 1, further comprising a processor in electronic communication with the 2D imaging camera, the processor configured to identify defects in the gray field image from the 2D imaging camera. system.

Directing a light beam from a light source to a wafer on a chuck;
reflecting the light beam at the wafer to a 2D imaging camera;
A first movable focus lens disposed on the path of the light beam between the light source and the wafer and a second movable focus lens disposed between the wafer and the 2D imaging camera are adjusted; , comprising independent changes to the illumination complex between the light source and the wafer and the light collection complex between the wafer and the 2D imaging camera;
using the 2D imaging camera to generate an image that is an image of the wafer and is a gray field image;
A method of determining the location of a defect on the wafer using the image.

10. The method of claim 9, wherein the focus of the light beam is below the surface of the wafer.

10. The method of claim 9, wherein the focus of the light beam is on the surface of the wafer.

10. The method of claim 9, wherein the focus of the light beam is above the surface of the wafer.

10. The method of claim 9, wherein the depth of focus of the light beam changes as it is scanned over the surface of the wafer.

10. The method of claim 9, further comprising directing the light beam through a structured mask disposed on the path of the light beam between the light source and the first movable focusing lens. a structured mask defining a plurality of apertures, the plurality of apertures forming bright zones on the surface of the wafer, and regions of the structured mask between the apertures defining dark zones on the surface of the wafer. How to form.

15. The method of claim 14, wherein the adjustment changes the position of the first movable focusing lens such that the structured mask is focused and light in the bright zone leaks into the dark zone. A method that includes something.

10. The method according to claim 9, wherein the illumination numerical aperture is between 0 and 0.9.

10. The method of claim 9, wherein the collection path numerical aperture is at least 0.9.

10. The method of claim 9, wherein the wafer has a 3D structure.

a light source that generates a beam of light;
objective system and
a chuck configured to hold a wafer in the path of the light beam through the objective;
a tunable illumination aperture disposed on the path of the light beam and between the light source and the objective;
a first movable focus lens disposed on the path of the light beam and between the light source and the objective system;
a 2D imaging camera configured to capture a wafer image within an area illuminated through the objective;
a second movable focus lens disposed on the path of the light beam and between the objective system and the 2D imaging camera;
Equipped with
the first movable focus lens and the second movable focus lens are configured to adjust an illumination complex between the light source and the wafer and a light collection complex between the wafer and the 2D imaging camera; the first movable focus lens and the second movable focus lens are configured to position an illumination focus at, above or below the surface of the wafer;
The system wherein the 2D imaging camera is configured to generate a gray field image of the wafer.

20. The system of claim 19, further comprising a structured mask disposed on the path of the light beam between the light source and the objective, the plurality of apertures through which the light beam passes through the structure. a structured mask, wherein a portion of the light beam is blocked by the structured mask.

21. The system of claim 20, wherein the structured mask is located between the light source and the first movable focal lens.

21. The system of claim 20, wherein the structured mask is configured to be oblique with respect to the path of the light beam.

20. The system of claim 19, wherein the system has an illumination numerical aperture of 0 to 0.9.

20. The system of claim 19, wherein the system has a collection path numerical aperture of at least 0.9.

20. The system of claim 19, further comprising a processor in electronic communication with the 2D imaging camera, the processor configured to identify defects in the gray field image from the 2D imaging camera. system.

Directing a light beam from a light source to a wafer on a chuck;
reflecting the light beam at the wafer to a 2D imaging camera;
adjusting an illumination complex between the light source and the wafer;
adjusting a light collection complex between the wafer and the 2D imaging camera;
using the 2D imaging camera to generate an image that is an image of the wafer and is a gray field image;
A method of determining the location of a defect on the wafer using the image.

27. The method of claim 26, wherein the focus of the light beam is below the surface of the wafer.

27. The method of claim 26, wherein the focus of the light beam is on the surface of the wafer.

27. The method of claim 26, wherein the focus of the light beam is above the surface of the wafer.

27. The method of claim 26, wherein the depth of focus of the light beam changes as it is scanned over the surface of the wafer.

27. The method of claim 26, further comprising directing the light beam through a structured mask disposed on the path of the light beam between the light source and the wafer; apertures, the plurality of apertures forming a bright zone on the surface of the wafer, and a region of the structured mask between the apertures forming a dark zone on the surface of the wafer. .

32. The method of claim 31, wherein the adjustment of the illumination complex and the light collection complex is such that the structured mask is focused and light in the bright zone leaks into the dark zone. The method includes changing the position of the first movable focusing lens on the path of a light beam.

27. The method of claim 26, wherein the illumination numerical aperture is between 0 and 0.9.

27. The method of claim 26, wherein the collection path numerical aperture is at least 0.9.

27. The method of claim 26, wherein the wafer has a 3D structure.