JPH03215928A - Exposure device - Google Patents

Abstract

PURPOSE:To avoid the enlargement of an XY stage and the elongation of stroke while enabling the illumination intensity distribution on a projection surface to be rapidly measured with high precision by making use of the output signals from a photodetector provided on a part of a wafer carrier hand. CONSTITUTION:A wafer carrier hand 2 is driven in the y axial direction by a specific amount along the driving feed screw 93 by a wafer hand motor 94 with the wafer carrier hand 2 holding no wafers at all while the position relative to the Z direction is adjusted. At this time, the shifting of a wafer carrier arm 92 in the y and Z directions is controlled so that a photodetector 31 comprising a unidimentional sensor provided on a part of said arm 92 may be positioned on the effective projection picture 8b. Through these procedures, the enlargement of an XY stage and the elongation of stroke can be avoided while the illumination intensity and distribution thereof in the arbitrary region on the effective projection picture 8b can rapidly be measured by a projection optical system with high precision, thereby enabling the projection printing process to be performed with high precision.

Description

Detailed Description of the Invention (Field of Application in Industry) The present invention relates to an exposure apparatus for semiconductor manufacturing, and in particular, a circuit pattern formed on a reticle surface is projected onto a wafer, which is a projection surface, using a projection optical system. The present invention relates to an exposure apparatus provided with an illuminance measuring means for measuring illuminance and illuminance distribution within a projection plane during projection exposure at a predetermined magnification.

(Prior art) In recent semiconductor manufacturing technology, as electronic circuits have become highly integrated, the resolution pattern line width has become, for example, 1 μm or less, and optical exposure equipment has also become more resolving power than before. It is requested.

Generally, when projecting a circuit pattern on a reticle surface onto a wafer surface (projection surface) via a projection optical system, the resolution line width of the circuit pattern is determined by the wavelength used, NΔ of the projection optical system, etc. on the projection surface. The uniformity of the illuminance distribution has a great influence.

For this reason, many conventional exposure devices do not place the wafer in the XY
The illuminance distribution on the projection plane is measured by various methods by placing an illuminance cutter on the stationary surface.

For example, (a) place a low illuminance 'A' on a part of the XY station on which the wafer is placed, and measure the illuminance distribution by moving the illumination meter on the xY station onto the projection plane as necessary. Method.

(Explanation) A method in which an illuminance meter is placed on a part of the xY station surface each time a measurement is made, and the illuminance 41 within the projection plane is measured while moving the XY station.

etc. are used.

(Problem to be solved by the invention) Of the methods for measuring the illuminance distribution on the projection plane, the method (a) above is
As the Y station becomes larger, the driving force of the XY station increases. Therefore, if you try to set the moving speed (acceleration) to the same value as before installing the illumination meter, the excitation force of the xY station will increase, the vibration of the entire device will increase, the alignment accuracy will decrease, and the resolution will decrease. It's coming. There was also the problem that if the exposure device vibrations were to settle down, the throughput would drop.

There is also the problem that as the movable stroke of the XY station increases, which requires moving the illumination wound placed on the XY station over the entire projection area, the processing range of the xY station increases, making it difficult to move with high precision. Ta.

However, with the method mentioned above, is it possible to prevent the increase in the size of the XY station and the increase in the movable stroke? If the wafer chuck is attached/detached repeatedly, the throughput decreases, and the parallelism between the wafer chuck and the projection surface of the projection optical system changes, resulting in a decrease in resolution. .

The present invention provides a photodetector in a part of the wafer loading hand for loading the wafer in the exposure apparatus onto the XY stage, and uses the output signal from the photodetector to increase the size of the XY stage. It is an object of the present invention to provide an exposure apparatus capable of quickly and highly accurately measuring illuminance and illuminance distribution within a projection plane while preventing the stroke from becoming long, and capable of high-resolution projection printing.

(Means for Solving the Problems) The exposure apparatus of the present invention illuminates a projection object placed on an irradiated object with a light beam from an illumination system, and projects the projection object using a projection optical system using a conveying hand. In an exposure apparatus configured to project at a predetermined magnification onto an object to be projected onto a surface,
A light detection section is disposed in a part of the transport hand, and by using the transport hand, the illuminance or /
The present invention is characterized in that an illuminance measuring means for measuring the illuminance distribution is provided.

In addition, the present invention is characterized in that the photodetecting section is constituted by a one-dimensional sensor in which a plurality of elements are arranged in a one-dimensional direction, and the carrying hand is moved within a plane perpendicular to the optical axis of the projection optical system. It is said that

(Embodiment) FIG. 1 is a schematic view of a main part of a first embodiment of the present invention, and FIG. 2 is an enlarged explanatory view of a portion of FIG. 1.

In FIGS. 1 and 2, reference numeral 1 indicates an illumination system. The illumination system 1 includes a light source 101 consisting of an ultra-high pressure mercury lamp or an excimer laser;
An illumination optical system 102 uniformly irradiates the light beam from the light source 101 through a half mirror 103 and mirrors 104 and 105 onto the surface of a reticle 5, which is a projection object placed on an irradiated surface.
have.

Further, in this embodiment, a part of the light beam from the light source 101 is reflected by the half mirror 103, and the light beam from the light source 101 is reflected by the condensing lens 106.
The light is guided to a light receiving element 107 for measuring the radiation intensity of 1.

On the surface of the reticle 5, a circuit pattern to be projected and transferred onto the wafer 9, which is the object to be projected, is formed on a quartz plate and enlarged several times.

A projection lens system 8 projects the circuit pattern on the reticle 5 onto the wafer 9 at a predetermined magnification. 8a is the optical axis of the projection lens system 8, and 8b is the effective projection screen of the projection lens system 8.

Reference numeral 2 denotes a wafer transfer hand, which includes a wafer holding section 9l and a wafer holding section 9 that hold the wafer 9 when transferring the wafer 9.
It has a wafer transfer arm 92 that supports wafer 1.

Reference numeral 93 is a feed screw for driving the wafer hand, which regulates movement of the wafer transfer hand 2.

Reference numeral 94 denotes a wafer hand drive motor that drives the wafer transfer hand 2 along the wafer hand drive feed screw 93.

A wafer hand drive encoder (not shown) is provided in a part of the wafer hand drive motor 94 to detect the amount of movement of the wafer transfer hand 2 . Further, the wafer hand 2 is movable in the optical axis direction (Z direction) of the projection lens system 8. 3 is an illuminance measuring means. The illuminance detection means 3 includes a photodetector section 31 mounted on a part of the wafer transfer arm 92, a briambe 32, an illuminance distribution calculation section 33, and an illuminance meter 34. The photodetector 3l is composed of a one-dimensional sensor in which a plurality of elements are arranged in one-dimensional direction (X direction). 4l is an X stage that moves in the X direction, and 42 is a Y station that moves in the Y direction.

The X stay 41 is supported by the Y stay 42.

A stationary surface plate 43 supports the X stage 4l and the Y stage 42.

A DC servo motor 6 is supported by the Y stage 42 and drives the X station 4l in the X direction.

Reference numeral 44 denotes a base surface plate on which various elements such as the wafer transfer hand 2, the wafer hand drive motor 94, the X stage, and the Y stage are mounted.

Reference numeral 7 denotes a lens barrel surface plate that supports the illumination system 1 and the projection lens system 8.

In this embodiment, when projecting and exposing the circuit pattern on the 5th surface of the reticle 1- to the 9th wafer surface 2 using the projection lens system 8, the wafer 9 is transferred from the wafer 8 cassette (not shown) using a wafer supply hand (not shown). It is supplied to the wafer holding section 9l of the wafer transfer hand 2. Then, it is vacuum-adsorbed and held. The wafer transfer hand 2 on which the wafer 9 is placed is connected to the wafer hand drive feed screw 9 by a wafer hand drive motor 94.
The wafer 9 is driven in the y-axis direction along the
It is placed on the Y stage. Then, the resicle 5 and the wafer 9 are aligned by driving the xY stage. Thereafter, the circuit pattern on the resicle 5 surface illuminated by the exposure light from the illumination system 1 is projected onto the wafer 9 surface by the projection lens system 8 and exposed.

By repeating the process from alignment of the reticle 5 and wafer 9 to projection exposure multiple times, the circuit pattern on the surface of the reticle 5 is projected and exposed onto the entire surface of the wafer 9.

After the projection exposure of the entire surface of the wafer 9 is completed, the wafer 9 is recovered from the xY stage by the wafer transfer hand 2 and carried out of the apparatus.

Next, when measuring the illuminance and/or illuminance distribution within the projection plane (corresponding to the image plane of the reticle pattern) by the projection lens system 8, the reticle 5 is carried out from the reticle stage by a reticle hand (not shown).

Then, while no wafer is held in the wafer transfer hand 2, the wafer hand drive motor 94 drives the wafer transfer hand 2 by a predetermined amount in the y-axis direction along the driving feed screw 92. Also, the position in the Z direction is adjusted.

At this time, the movement of the arm 92 in the y and Z directions is controlled so that the photodetector 31, which is a one-dimensional sensor provided on a part of the wafer transfer arm 92, is located within the effective projection screen 8b of the projection lens system 8. Ru.

Next, the light source 101 is turned on, and the inside of the effective projection screen 8b of the projection lens system 8 is illuminated with the light beam from the illumination system 1. The illuminance within the projection screen is sequentially measured by moving the wafer transfer hand 2 in the y-axis direction so that the photodetector 3l scans the y-axis direction within the effective projection screen 8b.

At this time, the signals photoelectrically converted by the photodetector 31 are sequentially transmitted to the illuminance distribution calculation section 33 via the preamplifier 32. Then, the illuminance distribution calculating section 33 refers to the signal from the illuminance meter 34 and measures the illuminance distribution within the projection plane by the projection optical system 8.

In this embodiment, the photodetecting section 31 may be constituted by a two-dimensional sensor in which a plurality of elements are two-dimensionally arranged. At this time, if the effective light receiving surface of the two-dimensional sensor is larger than the effective projection surface of the projection optical system, the two-dimensional sensor can be moved onto the effective projection surface using the wafer transfer hand 2, and then the wafer transfer hand 2 can be fixed. You can also measure the illuminance distribution.

If it is too small, move the wafer transfer hand 2 to measure the illuminance in each area, and use the illuminance distribution calculation unit 33 to calculate the illuminance distribution in the projection plane by referring to the illuminance at each measurement position and the signal from the illuminance meter 34. I try to ask for it.

In this embodiment, the present invention 11 can be applied even if a mirror system having a concave mirror and a convex mirror is used instead of the projection lens.

(Effects of the Invention) According to the present invention, as described above, a photodetector which is part of the illuminance measurement means is provided in a part of the wafer transfer hand, and by using the wafer transfer hand, the XY station can be made larger and longer. Achieved an exposure device that can prevent stroke formation and quickly and highly accurately measure the illuminance and illuminance distribution in any ψ range on the effective projection surface by the projection optical system, and can perform highly accurate projection printing. I can do that.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention, and FIG. 2 is an enlarged explanatory diagram of a portion of FIG. 1. In the figure, 1 is an illumination system, 2 is a wafer transfer hand, 3 is an illuminance measuring means, 5 is a reticle, 6 is a DC servo motor, 7 is a lens barrel surface plate, 8 is a projection lens system, 9 is a wafer, 101 is a light source,
107 is a light receiving element 102 is an illumination optical system, 3l is a photodetector, 32 is a preamplifier, 33 is an illuminance distribution calculation unit, 34 is an illumination meter, 4l is an X station, 42 is a Y station, 43 is a stage 12 surface plate , 44 is a base surface plate, 9l is a wafer holding part, 92
is the wafer transfer arm, 93 is the wafer hand drive screw,
Reference numeral 94 denotes a wafer hand driving motor.

Claims (3)

[Claims] (1) A projection object placed on the irradiation surface is illuminated with a light flux from the illumination system, and the projection object is transferred to the projection object surface by the projection optical system onto the projection surface with a predetermined magnification. In an exposure apparatus configured to project on the projection surface, a light detection unit is disposed in a part of the transport hand, and the illuminance and/or illuminance distribution on the projection surface is measured by using the transport hand. An exposure apparatus characterized by being provided with a measuring means. (2) The photodetector is configured with a one-dimensional sensor in which a plurality of elements are arranged in one-dimensional direction, and the transport hand is moved in a plane perpendicular to the optical axis of the projection optical system. An exposure apparatus according to claim 1. (3) The exposure apparatus according to claim 1, wherein the light detection section is constituted by a two-dimensional sensor having an area substantially equivalent to an effective projection surface by the projection optical system.