JPH047815A - Vertical stepper - Google Patents

Abstract

PURPOSE:To enable the precise stage position to be measured constantly by a method wherein a gas leakage cut off means is arranged in the route of laser beams emitted from a laser interference type position measuring instrument. CONSTITUTION:A gas leakage cutting-off means 11 comprising a cylindrical sealing material seals up a stage movable part 1 including a wafer chuck and a fixing base 3. The position of a wafer 101 (or a mask 103) during exposure step is measured by the laser beams 102 emitted from a laser interference type measuring instrument 104. At this time, the gas (inert gas) filling up the atmosphere encircling the mask 103 and the wafer 101 is cut off by said cutting off means 11 not to leak out in the laser pass side. Through these procedures, the laser pass will not be disturbed by the insert gas thereby enabling the precise stage position to be measured constantly.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a vertical stepper that uses synchrotron radiation light as a light source to expose and transfer an LSI pattern drawn on a mask onto a wafer. It is used to expose and transfer the circuit pattern drawn on the mask onto the wafer, with the aim of making it possible to accurately measure the stage position. Synchrotron radiation is used as the exposure light source, and the In a vertical stepper equipped with a mechanism for filling an atmosphere surrounding a mask and the wafer with a specific gas, and a laser interferometric position measuring device for detecting the position of the mask or the wafer, the laser beam of the position measuring device is The configuration is such that a gas leakage blocking means is provided to prevent the specific gas from leaking into the path through which the gas passes.

[Industrial Application Field] The present invention is directed to synchrotron radiation (hereinafter abbreviated as SOR).
The invention relates to a vertical stepper used as a light source to expose and transfer an LSI pattern drawn on a mask onto a wafer.

In recent years, DRAM (Dynam
As a means of storing highly integrated LSIs such as icRandom Access Memory), SOR
The exposure transfer method based on the method is attracting attention. This exposure method has 2 points compared to the conventional method of transferring a pattern using Shiyu 1 line Cg line 51 lines). ■The light source has a high intensity, so the throughput is large. ■The light source has a short wavelength
Using i, 2. Save 1. It is possible to transfer patterns with sub-micron widths. ■Because the light source has good parallelism, it can be used as a muff! It has the characteristics that adjusting the spacing between the wafers makes each area relatively larger.

This SORJ,;T exposure is normally performed in the atmosphere, but due to SOR, the mask or wafer reacts with the intoxication in the atmosphere, causing problems such as clouding of the mask.
, the exposure atmosphere surrounding the mask and wafer (T1.4)
A means of filling with an inert gas such as 16 is required.

[Prior art] In a conventional vertical stepper using SOR, the target is exposure transfer of a pattern with a quarter mirror pattern width of 1 inch, so the in-plane relative position of the mask and wafer is adjusted to 10 mm.
The darkness must be adjusted to 1/10,000th of a nua. Therefore, the sixth stage is used as a means for detecting the position of the stage.
As shown in the figure, in a fine movement XY-axis stage, a laser interferometric position measuring device 1 is attached to a plane mirror 2 that is linked to a stage movable section including a wafer chuck that holds a wafer 101.
A high-precision position detection method is used in which the position of the stage is detected by irradiating one norther beam 102 from 04 and using the interference of the reflected light.

In Figure 6, 103 is a mask, 3 is a mask 103
This is a fixing base for fixing a mask chuck (not shown) that holds the mask.

[Problems that the invention attempts to solve']However, the position measuring device that uses this interference has problems with the gas, changes in the refractive index, and atmospheric pressure in the path that the laser bus passes through (hereinafter abbreviated as the laser bus). There is a drawback that the monthly value changes slightly due to the influence of temperature, humidity, etc., resulting in an error in the length measurement value G. On the other hand, especially in the exposure method using SOR as a light source, in order to prevent the inconvenience of the mask or wafer reacting with oxygen in the atmosphere and causing the mask to become cloudy, as shown by the arrow line in Fig. Masked by active gas.

It is necessary to fill the exposure atmosphere surrounding the wafer.

4 is an inert gas outlet such as lie.

However, 1. If this inert gas leaks to the laser bus side,
This has the disadvantage that the refractive index of the laser changes and the length measurement error increases dramatically.

An object of the present invention is to provide a vertical stepper that can always accurately measure the stage position using a laser interferometric position measuring device.

[Means to solve the problem]

FIG. 1 is an explanatory diagram of the principle of the present invention, and in the figure, reference numeral 11 indicates gas leakage blocking means. Note that the same reference numerals are used for the same constituent members as in the prior art.

The gas leakage blocking means 11 is shown in this figure as an example composed of a cylindrical sealing material with a cross-sectional shape, and the sealing material is
The space between the stage movable part 1 including the wafer chuck and the fixed base 3 is closed.

[For production]

During exposure, position the wafer chuck 1 and
The wafer 101 on the wafer is placed opposite the mask 103, and the wafer 1 is irradiated with SOR from the right side of FIG.
A mask pattern is exposed onto the 01.

The wafer 101 (or mask 10
The positioning in step 3) is performed in the same manner as in the prior art using a laser beam 102 from a laser interferometric position measuring device. In this case, the gas (inert gas) filling the atmosphere surrounding the mask 103 and the wafer 101 is blocked by the gas leakage blocking means 11 and does not leak out to the laser bus side. Therefore, the laser bus is not disturbed by the inert gas, making it possible to always accurately measure the stage position.

〔Example〕

The present invention will now be described in detail with reference to FIGS. 2 to 5. Note that the same reference numerals are used for members similar to those in the past.

FIG. 2 shows an outline of the stage configuration of a vertical stepper that is common to each of the embodiments described below. Out-of-plane direction (gap 13σ
) Direction) Fine movement gap alignment axis stage 1
It is broadly divided into 4. The stage movable part 1 including the wafer chuck which is the movable part of the fine movement XY axis stage is 1. Microtremor x
It is supported by a fixed part 15 of the Y-axis stage via a parallel spring 16, and is configured to be displaced within a plane by a linear actuator (not shown). The position of the stage is determined by a laser beam l[j
2, it can be measured with high accuracy. Also,
The fixed part 15 of the fine movement XY axis stage is fixed by vacuum suction.
Fixing base for fine movement gear knob alignment axis stage 14, i 1.
'Double adsorption is fixed. "7th screen 103 is fixed 1'
93 is supported via the aphram spring 18, and the 7-piece rack 17 (corresponding to the movable part of the micro-adjustment gap adjustment shaft nut 1.4) is vacuum-adsorbed, and the mass is vacuum-adsorbed.
, l('+3. Gap amount between wafers 101 and (turret M
+: 5 "j:, q, , (' ((P is driven in the direction of matching!J. He is blown out by the inert gaff at a constant flow rate from the lower air outlet 704, and the parallel spring 16 and diaphragm He flows through the gap between the wing springs 1B as shown by the arrow line.In the state shown in FIG. The laser beam enters and disturbs the laser beam 102, reducing its length measurement accuracy.

Next, various embodiments equipped with gas leakage blocking means to solve this problem will be described.

FIG. 3 shows a first embodiment.

FIG. 3 is an explanatory diagram of the main part structure of the vertical stepper of this example, and is 21
is an O-ring (gas leakage blocking means).

The O-ring 2J is inserted between the fixing part 15 and the wafer chuck, thereby creating a structure that prevents He from leaking at least toward the laser beam side.

That is, according to this example, the one-no-the-bath is not disturbed by the inert gas, making it possible to always accurately measure the stage position.

Figure 4 shows numbers 2 and 7. ) Embodiment 6 FIG. 4 is an explanatory view of the main parts of the vertical stemmer of this example, and 31 is a labyrinth seal (gas leakage blocking means). The labyrinth seal 31 has a well-known structure, and includes a plurality of protrusions 32 that are provided on the fixed part J5 and the stage movable part 1 including the wafer chuck, respectively, and that engage with each other through minute gaps.
．． 33.

In the case of this example, it is possible to solve the problem that the structure of the previous example is a contact type, which makes it unusable depending on the application, and it is possible to minimize the amount of Hs leaking to the laser beam side. However, since the labyrinth seal is a non-contact type seal, there is a concern that some He may leak to the laser beam side. A third embodiment is shown in FIG.

Figure 5 is an explanatory diagram of the main part structure of the vertical stepper of this example.
1 is the gas leakage blocking means. Gas leakage blocking means 41
The He suction port 42 and the hole 4 provided in the stage movable part including the wafer chuck;
3, a suction vibrator 44 connected to the suction vibrator 44, and a suction source such as a blower (not shown) connected to the suction vibrator 44. All He leaking to the laser beam side is sucked by the gas leakage blocking means 4. Leakage of He to the laser beam side is eliminated.

In the case of this example, although it is a non-contact type, upward leakage of He can be eliminated and the same effect as the first example can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a mask is provided.

It is possible to minimize the leakage of inert gas such as He that fills the atmosphere surrounding the wafer into the laser beam bus of the laser interferometric position measuring device that measures the stage position, ensuring accurate positioning at all times. Stage 4: Measure i position. Two and two are kahoku 'r' knees.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a schematic diagram of the stage configuration of a vertical stepper according to an embodiment of the present invention, and Fig. 3 is a main structure of a dairy stepper according to a first embodiment of the present invention. Explanatory diagram, Fig. 4 is an explanatory diagram of the main part structure of a regular stepper according to the second embodiment of the present invention, and Fig. 5 is an explanatory diagram of the main part structure of a vertical stepper, 7 pax, according to the third embodiment of the present invention. FIG. 6 is an explanatory diagram of the main part structure of a conventional vertical stepper. In the figure, 11 is a gas leak blocking means, 101 is a wafer, and 103 is a mask.

Claims (1)

[Scope of Claims] Used when exposing and transferring a circuit pattern drawn on a mask (103) onto a wafer (101), synchrotron radiation is used as an exposure light source, and the mask (103) ), a mechanism for filling a specific gas into the atmosphere surrounding the wafer (101), and a mechanism for filling the atmosphere surrounding the wafer (101) with a specific gas;
03) Or in a vertical stepper equipped with a laser interferometric position measuring device (104) that detects the position of any one of the wafers (101), in the path through which the laser beam of the position measuring device (104) passes. A vertical stepper characterized in that a gas leakage blocking means (11) is provided to prevent the specific gas from leaking.