Photomask, method for manufacturing lens, and method for manufacturing photodetector

Patent metadata

Field	Value
Publication number	US-2023296978-A1
Application number	US-202217822766-A
Country	US
Kind code	A1
Filing date	Aug 26, 2022
Priority date	Mar 17, 2022
Publication date	Sep 21, 2023
Grant date	—

Abstract

According to one embodiment, a photomask includes a plurality of unit regions arranged in a first direction and a second direction crossing the first direction. Each of the unit regions includes a first region having a first light-shielding rate, and a second region having a second light-shielding rate different from the first light-shielding rate. The second region is provided around the first region. The unit regions include a first unit region and a second unit region having same size each other. A distance between the first unit region and a center of a range in which the unit regions are arranged is different from a distance between the second unit region and the center. A light-shielding rate of the first unit region is different from a light-shielding rate of the second unit region.

First claim

What is claimed is:

1 . A photomask, comprising:
a plurality of unit regions arranged in a first direction and a second direction crossing the first direction, each of the unit regions including
a first region having a first light-shielding rate, and
a second region having a second light-shielding rate different from the first light-shielding rate, and provided around the first region,
the unit regions including a first unit region and a second unit region having same size each other, a distance between the first unit region and a center of a range in which the unit regions are arranged being different from a distance between the second unit region and the center, and a light-shielding rate of the first unit region being different from a light-shielding rate of the second unit region.

2 . The photomask according to claim 1 , wherein
a size of the first region included in the first unit region is different from a size of the first region included in the second unit region.

3 . The photomask according to claim 1 , wherein
the unit regions further include a third unit region having same size as the first unit region or the second unit region, a distance between the first unit region and the center is longer than a distance between the second unit region and the center, and shorter than a distance between the third unit region and the center, and the light-shielding rate of the first unit region is higher than a light-shielding rate of one of the second unit region and the third unit region, and lower than a light-shielding rate of another of the second unit region and the third unit region.

4 . The photomask according to claim 1 , wherein
each of a plurality of the first regions has a size corresponding to a distance from the center.

5 . The photomask according to claim 1 , wherein
the first light-shielding rate of the first region included in the first unit region is smaller than the first-light shielding rate of the first region included in the second unit region.

6 . The photomask according to claim 1 , wherein
a light-shielding rate of each of the unit regions is inversely proportional to a square of a distance from the center.

7 . The photomask according to claim 1 , wherein
a light-shielding rate of each of the unit regions is in a relationship obtained by multiplying a ratio inversely proportional to a square of a distance from the center by a conic constant in a range of −0.2 to −5.0 or a square of the conic constant.

8 . The photomask according to claim 3 , wherein
the light-shielding rate of the first unit region is larger than a light-shielding rate of the third unit region, and smaller than a light-shielding rate of the second unit region, and a light-shielding rate of each of the unit regions is not less than 10% and not more than 90%.

9 . The photomask according to claim 1 , wherein
an area of each of a plurality of the first regions increases in proportion to a distance from the center.

10 . The photomask according to claim 1 , wherein
the first light-shielding rate is lower than the second light-shielding rate.

11 . The photomask according to claim 1 , wherein
the unit regions are arranged in the first direction and the second direction at an interval of a first distance.

12 . The photomask according to claim 11 , wherein
the first distance is not less than 500 nm and not more than 2500 nm.

13 . The photomask according to claim 1 , wherein
a diameter of at least one of inscribed circles in a plurality of the first regions is larger than 400 nm, the first regions include adjacent first regions in the first direction or the second direction, and a distance between the adjacent first regions is shorter than 200 nm.

14 . A method for manufacturing a lens, comprising:
exposing a resist on a photodetection element by using the photomask according to claim 1 ; and developing the resist.

15 . A method for manufacturing a photodetector, comprising:
forming a photodetection element; exposing a resist on a photodetection element by using the photomask according to claim 1 ; and forming a lens by developing the resist.

16 . A method for manufacturing a photodetector, comprising:
forming a photodetection element and a circuit on a same substrate, the circuit being configured to select or control the photodetection element; forming an insulating layer on the substrate; exposing a resist by using the photomask according to claim 1 ; and forming a plurality of lenses on the insulating layers by developing the resist.

17 . The method for manufacturing the photodetector according to claim 16 , wherein
the lenses are etched, the lenses include adjacent lenses in the first direction or the second direction, and a gap between the adjacent lenses is shortened by the etching.

18 . The method for manufacturing the photodetector according to claim 16 , wherein
a center of the photodetection element in a first surface parallel to the first direction and the second direction and a center of one of the lenses in the first surface are on a same axis crossing the first surface, and the lenses include the lenses being in contact with each other in the first direction or the second direction.

19 . A photomask comprising:
a plurality of non-light-shielding portions arranged two-dimensionally repeatedly; and a light-shielding portion arranged around each of the non-light-shielding portions, the non-light-shielding portions and the light-shielding portion being arranged so that a light-shielding rate of a central area of the photomask being higher than a light-shielding rate of a peripheral area of the photomask.

20 . A photomask comprising:
a plurality of light-shielding portions arranged two-dimensionally repeatedly; and a non-light-shielding portion arranged around each of the light-shielding portions, the non-light-shielding portion and the light-shielding portions being arranged so that a light-shielding rate of a central area of the photomask being higher than a light-shielding rate of a peripheral area of the photomask.

Assignees

• Toshiba Kk

Inventors

• Kwon Honam
• Shimizu Mariko
• Okamoto Kazuaki
• Suzuki Kazuhiro

Classifications

• H10F39/024

  of coatings or optical elements · CPC title

• H10F39/8063 Primary

  Microlenses · CPC title

• G03F1/38 Primary

  Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof · CPC title

• B29D11/00298

  Producing lens arrays · CPC title

• G02B3/0012

  characterised by the manufacturing method · CPC title