JPH11186128A - Exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure device that can change exposure according to the change in the resist film thickness to enable appropriate exposure. SOLUTION: Exposure time required to change the initial value to the appropriate exposure value depending on the change in the resist film thickness is preset in the exposure time setting unit 3. The reflected light intensity is calculated in the light intensity calculating unit 6, based on data received at the light receiving unit 4. A shutter 2 is operated by the open/close time control unit 5 to finish exposure depending on the time required to change the initial value to the appropriate exposure value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an exposure apparatus for transferring a pattern onto a substrate.

[0002]

2. Description of the Related Art An exposure apparatus of this type is used for transferring a pattern onto a substrate in a process of manufacturing a semiconductor device or the like.

[0003] An exposure apparatus according to a conventional example includes a light-emitting unit that irradiates light having a wavelength that does not expose the resist, a light-receiving unit that receives reflected light emitted from the light-emitting unit and reflected by the resist,
An absorption spectrum intensity calculation unit that calculates the absorption spectrum intensity of the resist based on the light intensity data obtained from the light receiving unit, and an exposure time setting unit that presets the absorption spectrum intensity at a predetermined exposure time, wherein the calculation is performed. The shutter opening / closing time is controlled by comparing the absorption spectrum intensities (see JP-A-63-250118 and JP-A-2-304748).

[0004]

However, the exposure apparatus according to the prior art corrects the measured exposure amount to a predetermined fixed exposure amount irrespective of the change in the light reflectance of the object to be exposed. The problem is that even if the resist film thickness fluctuates, the amount of exposure cannot be increased or decreased, resulting in improper exposure, resulting in variations in dimensions and the like. Had occurred.

It is an object of the present invention to provide an exposure apparatus in which an exposure amount is made variable in accordance with a change in a resist film thickness so as to perform an appropriate exposure.

[0006]

In order to achieve the above object, an exposure apparatus according to the present invention comprises: an exposure light source;
An exposure apparatus having a light intensity calculation unit, an exposure time setting unit, and an opening / closing time control unit, wherein the exposure light source irradiates the exposure object with the exposure light, and the light receiving unit emits the exposure light. The light intensity calculation unit calculates the intensity of the light received by the light receiving unit, and the exposure time setting unit calculates the initial value by the light intensity calculation unit. To set the exposure time from the light intensity to the light intensity required for proper exposure, the opening and closing time control unit monitors the change value of the light intensity from the light intensity calculation unit, set in the exposure time setting unit When the light intensity required for proper exposure is reached,
This is for issuing an opening / closing command of an exposure light irradiation control shutter.

The exposure time set in the exposure time setting section is set in consideration of a change in the film thickness of the object to be exposed to the exposure light.

The light received by the light receiving section is reflected light reflected by the object to be exposed or scattered light diffused by the object to be exposed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram showing Embodiment 1 of the present invention.

Referring to FIG. 1, an exposure apparatus according to a first embodiment of the present invention includes an exposure light source 1, a shutter 2, a reflecting mirror 12
, An optical system 7, a light receiving unit 4, a light intensity calculating unit 6, an exposure time setting unit 3, and an opening / closing time setting unit 5.

The exposure light source 1 irradiates exposure light to a wafer 8 as an object to be exposed.

The shutter 2 is controlled to open and close so as to irradiate or not irradiate the wafer 8 with exposure light from the exposure light source 1. The reflecting mirror 12 reflects the exposure light from the exposure light source 1 toward the wafer 8 and reflects the reflected light 9 from the wafer 8 toward the light receiving unit 4. The optical system 7 focuses the exposure light from the exposure light source 1 on the wafer 8.

The light receiving section 4 receives reflected light 9 from the wafer 8.
The light intensity calculator 6 calculates the intensity of the light received by the light receiver 4.

The exposure time setting section sets an exposure time from a light intensity calculated as an initial value by the light intensity calculation section 6 to a light intensity required for proper exposure.

The opening / closing time controller 5 monitors the change in light intensity from the light intensity calculator 6 and, when the light intensity required for proper exposure set by the exposure time setting unit 3 is reached, the shutter 2 An open / close command is issued.

In FIG. 1, the exposure light emitted from the exposure light source 1 passes through the optical system 7 through the open shutter 2 and reaches the wafer 8, at which time reflected light 9 is generated at the wafer 8.

The reflected light 9 is received by the light receiving unit 4 and analyzed by the light intensity calculating unit 6, and the output signal is sent to the open / close time control unit
Output to The opening / closing time control unit 5 monitors a change value of the light intensity from the light intensity calculation unit 6 and, when the light intensity required for proper exposure set by the exposure time setting unit 3 is reached, an exposure light irradiation control unit. The exposure process is completed by closing the shutter 2.

(Embodiment 2) FIG. 2 is a configuration diagram showing Embodiment 2 of the present invention.

In the second embodiment shown in FIG.
The scattered light 10 diffused by the wafer 8 is detected instead of the reflected light 9 reflected by the light.

Exposure light emitted from the exposure light source 1 passes through the optical system 7 through the opened shutter 2 and reaches the wafer 8. At this time, scattered light 10 is generated on the surface of the wafer 8.

The scattered light 10 is received by the light receiving unit 4,
When the scattered light reaches the light intensity preset in the exposure time setting unit 3, the shutter 2 is closed by the opening / closing time control unit 5 to end the exposure processing. .

[0023]

As described above, according to the present invention, a change in the intensity of reflected light or scattered light due to a change in film thickness is monitored, and when the reflected light or scattered light is changed from an initial value to an appropriate exposure value in advance. In addition, since the exposure is stopped by closing the shutter, even if the resist film thickness changes, a problem caused by an inappropriate exposure amount such as dimensional variation can be avoided by optimizing the exposure amount.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exposure light source 2 Shutter 3 Exposure time setting part 4 Light receiving part 5 Opening / closing time setting part 6 Light intensity calculation part 7 Optical system 8 Wafer 9 Reflected light 10 Scattered light 11 Light intensity calculation part 12 Reflecting mirror

Claims (3)

[Claims] 1. An exposure apparatus comprising an exposure light source, a light receiving unit, a light intensity calculation unit, an exposure time setting unit, and an opening / closing time control unit, wherein the exposure light source irradiates the exposure object with an exposure light. The light receiving unit receives the light from the object to be exposed due to the irradiation of the exposure light, and the light intensity calculating unit calculates the intensity of the light received by the light receiving unit. The setting unit is for setting an exposure time from the light intensity calculated as an initial value by the light intensity calculation unit to the light intensity required for proper exposure, and the opening / closing time control unit is configured to control the light intensity from the light intensity calculation unit. An exposure apparatus for monitoring a change value and issuing an opening / closing command of an exposure light irradiation control shutter when a light intensity required for proper exposure set by an exposure time setting section is reached. 2. The apparatus according to claim 1, wherein the exposure time set in the exposure time setting unit is set in consideration of a change in a film thickness of the object to be exposed to which exposure light is irradiated. Exposure equipment. 3. The exposure apparatus according to claim 1, wherein the light received by the light receiving unit is reflected light reflected by the object to be exposed or scattered light diffused by the object to be exposed.