LITHOGRAPHY ILLUMINATION SYSTEM

• US 20150286144A1
• Filed: 06/19/2015
• Published: 10/08/2015
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: Shanghai Institute Of Optics And Fine Mechanics Chinese Academy Of Sciences
• Original Assignee: Shanghai Institute Of Optics And Fine Mechanics Chinese Academy Of Sciences
• Inventors: ZENG, Aijun, ZHU, Linglin, FANG, Ruifang, HUANG, Huijie
• Granted Patent: US 9,400,433 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 19/0047 for use with a light source G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G02B 3/0037 characterized by the distribution or form of lenses
• CPC Class Codes: G03F 7/70066 Size and form of the illuminated area in the mask plane, e.g. reticle masking blades or blinds
• CPC Class Codes: G03F 7/70075 Homogenization of illumination intensity in the mask plane by using an integrator, e.g. fly's eye lens, facet mirror or glass rod, by using a diffusing optical element or by beam deflection
• CPC Class Codes: G03F 7/7015 Details of optical elements

Abstract

A lithography illumination system, along the transmission direction of the laser light, successively comprising a laser light source, a collimating and expanding unit, a pupil shaping unit, a first micro-lens array, a micro-integrator rod array, a micro-scanning slit array, a second micro-lens array, a condenser lens group, a mask, and and a motion control unit for controlling the motion of the micro scanning slit array.

Claims

1. A lithography illumination system comprising:

a laser light source,

a collimating and expanding unit,

a pupil shaping unit having an exit pupil plane,

a first micro-lens array having a back focal plane and being composed of multiple identical first micro-lenses, and each of the first micro-lenses having a field angle,

a second micro-lens array having a front focal plane and a back focal plane, and being composed of multiple identical second micro-lenses, and each of the second micro-lenses having a field angle,

a condenser lens group,

a mask,

a micro-scanning slit array,

a motion control unit, and

a micro-integrator rod array having an entrance end surface and an exit end surface, and being composed of multiple identical micro-integrator rods;

wherein lithography illumination system is arranged such that a beam emitted from the laser light source passes sequentially through the collimating and expanding unit, the pupil shaping unit, the first micro-lens array, the micro-integrator rod array, the micro-scanning slit array, the second micro-lens array, and the condenser lens group, and illuminates the mask;

the motion control unit is connected to the micro-scanning slit array for controlling a moving speed and distance of the micro-scanning slit array to scan a light field;

the first micro-lens array is located at the exit pupil plane of the pupil shaping unit;

the entrance end surface of the micro-integrator rod array is located at the back focal plane of the first micro-lens array;

the exit end surface of the micro-integrator rod array is located at the front focal plane of the second micro-lens array;

the back focal plane of the second micro-lens array and the mask are a pair of conjugated planes of the condenser lens group; and

each of the first micro-lenses, the micro-integrator rods, and the second micro-lenses are in one-to-one correspondence.

2. The lithography illumination system of claim 1, wherein the first micro-lenses are closely linked to each other, and each of the first micro-lenses is a cylindrical lens or a spherical lens.

3. The lithography illumination system of claim 1, wherein the second micro-lenses are closely linked to each other, and each of the second micro-lenses is a cylindrical lens or a spherical lens.

4. The lithography illumination system of claim 1, wherein the field angle of the second micro-lens is different from the field angle of the first micro-lens.

5. The lithography illumination system of claim 1, wherein the micro-integrator rod is rectangular, two ends of the micro-integrator rods are respectively fixed by a first support frame and a second support frame in a two-dimension matrix with an interval, size of the interval is equal to or greater than a size of an end surface of the micro-integrator rod.

6. The lithography illumination system of claim 1, wherein the micro-scanning slit array is composed of multiple identical micro-scanning slits, each of the micro-scanning slits is located at the exit end surface of the micro-integrator rods and interspersed in the intervals of the micro-integrator rods.

7. The lithography illumination system of claim 1, wherein the micro-scanning slit array is composed of a first micro-scanning slit array having a nonopaque direction along a Y axis and a second micro-scanning slit array having a nonopaque direction along an X axis;

when the first micro-scanning slit array is controlled by the motion control unit to move along the X axis, X-direction of a light field is scanned in one dimension;

when the second micro-scanning slit array is controlled by the motion control unit to move along the Y axis, Y-direction of the light field is scanned in one dimension; and

when the first and second micro-scanning slit arrays respectively and simultaneously move along the X axis and Y axis, the light field is scanned in two dimension.

8. The lithography illumination system of claim 1, wherein the micro-scanning slit array is composed of a plurality of small-square scanning slits in two-dimension distribution;

when the small-square scanning slit is controlled by the motion control unit to move along an X axis, X-direction of a light field is scanned;

when the small-square scanning slit is controlled by the motion control unit to move along an Y axis, Y-direction of the light field is scanned; and

when the small-square scanning slit is controlled by the motion control unit to move along an angle bisectors of the X axis and the Y axis, the light field is scanned in two dimension.