Photomask, method of manufacturing optical element array, optical element array

Patent metadata

Field	Value
Publication number	US-9703015-B2
Application number	US-201514727111-A
Country	US
Kind code	B2
Filing date	Jun 1, 2015
Priority date	Jun 3, 2014
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A photomask for an optical element array includes first and second optical elements. A light transmission rate distribution includes a first area where the first optical element is to be formed, a second area where the second optical element is to be formed, and a third area between the first and second areas, has a first light transmission rate at an end portion of the first area. A second light transmission rate is higher than the first light transmission rate at another end portion. A third light transmission rate at an end portion corresponds to a boundary between the second and third areas. A fourth light transmission rate is higher than the third light transmission rate at another end portion of the second area. The light transmission rate distribution along a first direction is higher than a segment connecting the second and third light transmission rates in the third area.

First claim

What is claimed is:

1. A photomask for an optical element array comprising:
a first optical element having a bottom surface on a first surface including a first direction and a second direction that intersects the first direction; and
a second optical element having a bottom surface on the first surface and arranged so as to abut on the first optical element along the first direction,
wherein a light transmission rate distribution of the photomask along the first direction includes a first area in which the first optical element is to be formed, a second area in which the second optical element is to be formed, and a third area provided between the first area and the second area,
wherein the light transmission rate distribution of the photomask along the first direction includes:
a first light transmission rate at an end portion of the first area;
a second light transmission rate having a light transmission rate higher than the first light transmission rate at another end portion of the first area, which corresponds to a boundary between the first area and the third area on a side opposite to the end portion;
a third light transmission rate at an end portion, which corresponds to a boundary between the second area and the third area; and
a fourth light transmission rate having a light transmission rate higher than the third light transmission rate at another end portion of the second area on a side opposite to the end portion, and

wherein the light transmission rate distribution of the photomask along the first direction includes: the light transmission rate higher than a segment of light transmission rate connecting the second light transmission rate and the third light transmission rate in the third area.

2. The photomask according to claim 1 , wherein
the light transmission rate distribution of the photomask along the first direction has a constant value along the first direction in the third area.

3. The photomask according to claim 1 , wherein
the light transmission rate distribution of the photomask along the first direction includes: the light transmission rate increasing from the third light transmission rate to the fourth light transmission rate in the third area between an end on the first area side and an end on the second area side at a constant rate.

4. The photomask according to claim 1 , wherein
the light transmission rate distribution of the photomask along the first direction includes: the light transmission rate increasing from the first light transmission rate to the second light transmission rate between an end of the first area and another end of the first area at a constant rate, and the light transmission rate increasing from the third light transmission rate to the fourth light transmission rate between another end of the second area side and the one end of the second area at a constant rate.

5. The photomask according to claim 1 , wherein
the third area is shorter than the first area and the second area in the first direction.

6. A method of manufacturing an optical element array comprising:
forming the optical element array by exposing by using the photomask according to claim 1 .

7. A method of manufacturing a photoelectric conversion apparatus comprising:
preparing a substrate having a plurality of photoelectric conversion elements;
forming a photosensitive member on the substrate; and
forming the optical element array on the substrate by exposing photoelectric conversion elements by using the photomask according to claim 1 .

8. A method of designing a photomask pattern data for an optical element array including a first optical element having a bottom surface on a first surface including a first direction and a second direction that intersects the first direction; and a second optical element having the bottom surface on the first surface and arranged so as to abut on the first optical element along the first direction, comprising:
acquiring design shapes of the first optical element and the second optical element;
acquiring a light transmission rate distribution of the photomask pattern data for the photomask having a first portion corresponding to the first optical element and a second portion corresponding to the second optical element from design shapes of the first optical element and the second optical element;
replacing a boundary between the first portion and the second portion, part of the first portion on the boundary side and part of the second portion on the boundary side with a third portion in the light transmission rate distribution; and
forming the photomask pattern data based on the light transmission rate distribution after the replacing with the third portion,
wherein the third portion has a first light transmission rate at the boundary with respect to the first portion and a second light transmission rate at the boundary with respect to the second portion, and
wherein the light transmission rate distribution in the third portion has a light transmission rate higher than a segment of light transmission rate connecting a light transmission rate at the boundary with respect to the first portion and a light transmission rate at the boundary with respect to the second portion.

9. A method of manufacturing a photomask comprising:
forming photomask pattern data by using a method of designing a photomask pattern data according to claim 8 ; and
manufacturing a photomask by using the photomask pattern data.

10. An optical element array having a plurality of optical elements comprising:
first optical elements arranged along a first direction and having bottom surfaces in the first direction;
second optical elements arranged along the first direction, having bottom surfaces in the first direction, and arranged so as to abut on the first optical elements; and
third optical elements arranged along the first direction, having bottom surfaces in the first direction, and arranged so as to abut on the first optical elements on an opposite side to a position where the second optical elements are arranged,
wherein the first optical elements include:
a first area which does not include an apex of a first optical element and in which a change of a surface shape of the first optical element is steep,
a second area which includes an apex of the first optical element and in which a change of the surface shape of the first optical element is gentle in cross-sectional view along the first direction, and
a distance W between a boundary between the first area and the second area and a boundary between an area in which the first optical element is formed and an area in which a second optical element is formed in the first direction and a distance H between the apex and the bottom surface of the first optical element in a direction orthogonal to the first direction satisfies a relationship 0.3H<W<0.5H.

11. The optical element array according to claim 10 , wherein
an angle θ formed between a straight line connecting the boundary between the first area and the second area and the boundary between the area in which the first optical element is formed and the area in which the second optical element is formed and the bottom surface has a relationship 2<tan−1θ<3.5.

12. The optical element array according to claim 10 , wherein
a pitch P in which the plurality of optical elements are formed and the distance W satisfies a relationship W<⅓·P.

Assignees

• Canon Kk

Inventors

• Sekine Yasuhiro
• Furuta Mariko
• Iwata Jun
• Watanabe Kyouhei

Classifications

• G03F7/0005

  Production of optical devices or components in so far as characterised by the lithographic processes or materials used therefor · CPC title

• G02B27/10

  Beam splitting or combining systems (polarising systems G02B27/28; mixing and splitting light signals using optical waveguides G02B6/28; {beam shaping, e.g. changing the cross-sectional area, by dividing or superposing multiple light beams G02B27/0905}) · CPC title

• G02B27/0927

  Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat · CPC title

• G02B3/0012

  characterised by the manufacturing method · CPC title

• G02B3/0056

  arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses (G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085) · CPC title