JP2007258472A - Exposure equipment - Google Patents

Abstract

The present invention relates to an exposure apparatus used for lithography such as a semiconductor integrated circuit, and an object thereof is to provide an exposure apparatus that does not need to separately operate a scanning direction light shielding member in response to a scanning operation of a reticle stage. To do.
An exposure is performed in which a reticle stage on which a reticle is arranged and a sensitive substrate stage on which a sensitive substrate is arranged are synchronously scanned, and a pattern of the reticle reflected by the reticle is transferred onto the sensitive substrate. In the apparatus, a scanning direction light-shielding member for limiting an exposure area in the scanning direction of the reticle is arranged on the reticle stage so as to be movable together with the reticle stage. Further, the scanning direction light shielding member is arranged to be relatively movable with respect to the reticle stage.
[Selection] Figure 3

Description

  The present invention relates to an exposure apparatus used for lithography such as a semiconductor integrated circuit.

In an EUV exposure apparatus that uses EUV light as exposure light, the reticle stage on which the reticle is placed and the wafer stage on which the wafer is placed are scanned synchronously, and the reticle pattern of the exposure light reflected by the reticle is placed on the wafer. Transfer exposure is performed.
Then, various exposure areas can be set by moving a light shielding member called a reticle blind to a predetermined position. In an EUV exposure apparatus, as a light shielding member, a fixed blind that defines an exposure region of exposure light, a scanning direction light shielding member that restricts an exposure region in the scanning direction of the reticle, and a non-scanning direction light shielding that restricts an exposure region in the non-scanning direction of the reticle. A member is disposed between the reticle and the projection optical system.
JP-A-6-232031

  However, the conventional EUV exposure apparatus has a problem that a scanning direction light-shielding member for limiting the exposure area in the scanning direction of the reticle is required to be separately driven in accordance with the scanning operation of the reticle stage. Since it is difficult in optical design to increase the distance between the reticle and the projection optical system, it is necessary to arrange the driving device in a narrow space, and the structure of the driving device becomes complicated. Further, as the scanning speed of the reticle stage increases, it is necessary to increase the operation of the light shielding member in the scanning direction. However, the increase in vibration increases the vibration generated in the light shielding member in the scanning direction and has an effect on the exposure accuracy. It cannot be ignored.

  The present invention has been made to solve such a conventional problem, and an object thereof is to provide an exposure apparatus that does not need to separately operate a scanning direction light shielding member in response to a scanning operation of a reticle stage.

  In an exposure apparatus according to a first aspect of the present invention, a reticle stage on which a reticle is arranged and a sensitive substrate stage on which a sensitive substrate is arranged are scanned synchronously, and the reticle pattern of the exposure light reflected by the reticle is detected on the sensitive substrate. In the exposure apparatus to be transferred upward, a scanning direction light shielding member for limiting an exposure area in the scanning direction of the reticle is disposed on the reticle stage so as to be movable together with the reticle stage.

An exposure apparatus according to a second aspect is characterized in that, in the exposure apparatus according to the first aspect, the scanning direction light blocking member is disposed so as to be movable relative to the reticle stage.
An exposure apparatus according to a third aspect is the exposure apparatus according to the first or second aspect, wherein the exposure area of the reticle in the non-scanning direction is restricted, and a fixed that defines the exposure area of the exposure light. And a blind.

An exposure apparatus according to a fourth aspect is the exposure apparatus according to the third aspect, wherein the exposure area of the exposure light has an arc shape, and the non-scanning direction light blocking member moves within the arc-shaped exposure area. It is characterized by.
An exposure apparatus according to a fifth aspect is the exposure apparatus according to the third or fourth aspect, wherein the scanning direction light shielding member, the fixed blind, and the non-scanning direction light shielding member are sequentially arranged from the side closer to the reticle. It is characterized by that.

An exposure apparatus according to a sixth aspect is the exposure apparatus according to any one of the second to fifth aspects, wherein the reticle stage is disposed on the movement table for moving the reticle in the scanning direction, and on the reticle. And an electrostatic chuck for adsorbing and moving means for moving the light blocking member in the scanning direction in the scanning direction, which is disposed on the moving table.
An exposure apparatus according to a seventh aspect is the exposure apparatus according to the sixth aspect, wherein the moving means is disposed at positions on both sides of the reticle of the moving table and guides the scanning direction light blocking member in the scanning direction. It is characterized by having a guide member.

  An exposure apparatus according to an eighth invention is the exposure apparatus according to any one of the second to fifth inventions, wherein the reticle stage is finely movable on a coarse motion table that moves the reticle in a scanning direction and the coarse motion table. A fine movement table arranged on the fine movement table, an electrostatic chuck arranged on the fine movement table and attracting the reticle, and a moving means arranged on the coarse movement table and moving the light blocking member in the scanning direction in the scanning direction. Features.

An exposure apparatus according to a ninth aspect is the exposure apparatus according to the eighth aspect, wherein the moving means is disposed at positions on both sides of the fine movement table of the coarse movement table and guides the scanning direction light shielding member in the scanning direction. And a pair of guide members.
An exposure apparatus according to a tenth invention is the exposure apparatus according to any one of the sixth to ninth inventions, wherein the electrostatic chuck has an adsorption surface formed on the lower surface for attracting the reticle. .

  In the exposure apparatus of the present invention, it is not necessary to separately operate the scanning direction light shielding member in response to the scanning operation of the reticle stage.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 shows a first embodiment of the exposure apparatus of the present invention.
The exposure apparatus includes a light source unit 11, an illumination optical system 13, a reticle stage 15, a projection optical system 17, and a wafer stage 19.

The light source unit 11 converts the target material into plasma and generates pulsed light composed of EUV light.
In the light source unit 11, a gas or liquid target material is intermittently ejected from the tip of the nozzle 21 to the light emitting unit 23. The laser beam 27 emitted from the laser device 25 is condensed on the target material via the lens 29, and the target material is turned into plasma. Thereby, EUV light 31 composed of pulsed light is generated.

The illumination optical system 13 guides illumination light to the lower surface of the reticle 33 arranged below the reticle stage 15.
In this illumination optical system 13, the EUV light 31 from the light source unit 11 becomes a substantially parallel light beam via the concave reflecting mirror 35 that acts as a collimator mirror, and is emitted from the first fly-eye mirror 37 and the second fly-eye mirror 39. Is incident on an optical integrator 41. Thereby, a substantial surface light source having a predetermined shape (in this example, an arc shape but not limited to this shape) is formed in the vicinity of the reflection surface of the second fly-eye mirror 39. The EUV light 31 from the substantial surface light source is reflected by the reflecting mirrors 43 and 45 and then deflected by the planar reflecting mirror 47.

  The reticle stage 15 has a moving table 49. The moving table 49 is movable in the X, Y, and Z directions. An electrostatic chuck 51 is fixed below the moving table 49, and a reticle 33 is held by suction on the lower surface of the electrostatic chuck 51. Below the reticle 33, scanning direction light shielding members 53 and 54, a fixed blind 55, and a non-scanning direction light shielding member 57 are arranged. Details of these light shielding members 53, 54, 55, and 57 will be described later.

  The EUV light 31 deflected by the plane reflecting mirror 47 passes through the openings of the non-scanning direction light shielding member 57, the fixed blind 55, and the scanning direction light shielding members 53 and 54, and is an elongated arc-shaped illumination area on the lower surface of the reticle 33. Form. For convenience of explanation, the non-scanning direction light blocking member 57, the fixed blind 55, and the scanning direction light blocking members 53 and 54 block the illumination light incident on the reticle 33, but block the light beam reflected from the reticle 33. Alternatively, the light beam may be shielded on both the incident side and the reflection side. In other words, it may be arranged so that the shape of the exposure area on the wafer can be finally defined.

The reticle 33 has a multilayer film that reflects the EUV light 31 and an absorber pattern layer for forming a pattern. The EUV light 31 is patterned by reflecting the EUV light 31 with the reticle 33.
The projection optical system 17 has four reflecting mirrors, and each of the mirrors 17 a to 17 d is provided with a multilayer film that reflects the EUV light 31. The EUV light 31 reflected and patterned by the reticle 33 is sequentially reflected from the first mirror 17 a to the fourth mirror 17 d to form a reduced image of the reticle pattern on the wafer 55.

  The wafer stage 19 is movable in the X, Y, and Z directions. An electrostatic chuck 59 is fixed on the upper side of the wafer stage 19, and the wafer 61 is attracted and held on the upper surface of the electrostatic chuck 59. When exposing the die on the wafer 61, the EUV light 31 is irradiated onto a predetermined area of the reticle 33, and the reticle 33 and the wafer 61 are at a predetermined speed according to the reduction ratio of the projection optical system 17 with respect to the projection optical system 17. It moves with. In this way, the pattern of the reticle 33 is exposed to a predetermined exposure range (with respect to the die) on the wafer 61.

2 and 3 show details of the reticle stage 15.
In FIG. 2, the electrostatic chuck 51 is fixed to the lower side of the moving table 49, and the reticle 33 is attracted and held on the attracting surface 51 a of the lower surface of the electrostatic chuck 51. Below the reticle 33, the projection optical system 17 is disposed, and between the reticle 33 and the projection optical system 17, the scanning direction light shielding members 53 and 54, the fixed blind 55 and the non-scanning direction light shielding member 57 are disposed.

  The scanning direction light shielding members 53 and 54 are movable in the scanning direction (Y direction) of the moving table 49 along the guide member 63 disposed on the moving table 49. On the lower surface of the moving table 49, as shown in FIG. 3, a pair of guide members 63 are arranged at positions on both sides of the reticle 33 (electrostatic chuck 51). The pair of guide members 63 extend in the scanning direction (Y direction) of the moving table 49. Scanning direction light blocking members 53 and 54 are arranged on the lower surfaces of the pair of guide members 63. The scanning direction light shielding members 53 and 54 are disposed across a pair of guide members 63, and both ends thereof are guided by the guide members 63.

  The guide member 63 is composed of, for example, a linear guide, and guides the slider 65 fixed to the end portions of the scanning direction light shielding members 53 and 54. The linear guide and the slider 65 constitute a linear motor, and the slider 65 is moved along the linear guide. The position of the slider 65 on the linear guide can be measured by a linear encoder (not shown). Then, as shown in FIG. 3, the reticle 33 is exchanged in a state where the scanning direction light blocking members 53 and 54 are positioned outside the reticle 33 in the scanning direction.

  In FIG. 3, a symbol S indicates an arcuate illumination area irradiated on the pattern surface of the reticle 33. The direction of the straight line passing through the center of the arcuate illumination area S in the radial direction is the scanning direction of the reticle 33. A pair of scanning direction light shielding members 53 and 54 that limit the scanning direction of the reticle 33 are arranged at positions on both sides of the illumination region S in the scanning direction. The scanning direction light blocking members 53 and 54 prevent the exposure area from protruding before and after scanning, and are sometimes called mask blinds or synchronous blinds.

  More specifically, at the start of the exposure operation, as shown in FIG. 4A, the scanning direction light shielding member 54 is moved along the guide member 63 so that the scanning direction light shielding member 54 covers the illumination area S. Therefore, the exposure area of the reticle 33 in the scanning direction is limited. At the end of the exposure operation, as shown in FIG. 4B, the scanning direction light shielding member 53 is moved along the guide member 63, and the scanning direction light shielding member 53 is positioned at a position covering the illumination area S. This limits the exposure area of the reticle 33 in the scanning direction. This prevents unnecessary illumination light from being applied to the wafer 61.

As shown in FIG. 3, the non-scanning direction light blocking members 57 are arranged on both sides of the arcuate illumination area S in the direction perpendicular to the scanning direction. The non-scanning direction light blocking member 57 determines the scanning width by limiting the non-scanning direction of the illumination area S. The non-scanning direction light shielding member 57 can be moved in a direction perpendicular to the scanning direction by a driving device (not shown).
The fixed blind 55 defines the shape of the arcuate illumination area S that is irradiated onto the reticle 33. The fixed blind 55 is a slit for determining the projection area of the projection optical system 17, and defines the maximum exposure area in the case of still exposure in which the reticle stage 15 is not scanned. Since the fixed blind 55 is desirably installed close to the pattern surface of the reticle 33 in terms of optical design, the fixed blind 55 is installed close to the lower side of the scanning direction light shielding members 53 and 54 as shown in FIG.

  In the exposure apparatus described above, since the scanning direction light blocking members 53 and 54 are provided on the moving table 49 of the reticle stage 15, the scanning direction light blocking members 53 and 54 move together with the moving table 49. Therefore, it is not necessary to separately operate the scanning direction light shielding members 53 and 54 in response to the scanning operation of the reticle stage 15 at the start and end of the exposure operation, and the synchronous operation of the reticle stage 15 and the scanning direction light shielding members 53 and 54 is performed. Control can be dispensed with.

Further, since both sides of the scanning direction light shielding members 53 and 54 are supported by the pair of guide members 63 arranged on the moving table 49, even if the scanning speed of the reticle stage 15 is increased, the scanning direction light shielding member 53, The vibration generated in 54 is not greatly increased, and the deterioration of the exposure accuracy due to the vibration of the scanning direction light shielding members 53 and 54 can be prevented.
Further, since the scanning direction light shielding members 53 and 54 are guided and moved by the pair of guide members 63 arranged on the moving table 49, the scanning direction light shielding members 53 and 54 can be quickly moved to a required position with high accuracy. Can move.
(Second Embodiment)
5 and 6 show a reticle stage 15A of the second embodiment of the exposure apparatus of the present invention.

In this embodiment, members having the same functions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In this embodiment, the reticle stage 15 </ b> A has a coarse movement table 71 and a fine movement table 73. The coarse motion table 71 is movable in the X, Y, and Z directions, and moves the reticle 33 in the scanning direction. The fine movement table 73 is arranged on the coarse movement table 71 so as to be finely movable. That is, the fine movement table 73 is held below the coarse movement table 71 via the posture control actuator 75 and can be finely moved by the posture control actuator 75.

An electrostatic chuck 51 is fixed below the fine movement table 73, and the reticle 33 is held by suction on the lower surface of the electrostatic chuck 51. Below the reticle 33, the projection optical system 17 is disposed, and between the reticle 33 and the projection optical system 17, the scanning direction light shielding members 53 and 54, the fixed blind 55 and the non-scanning direction light shielding member 57 are disposed.
The scanning direction light blocking members 53 and 54 can be moved in the scanning direction of the coarse movement table 71 along the guide member 63 disposed on the coarse movement table 71. As shown in FIG. 6, a pair of guide members 63 are disposed on the lower surface of the coarse movement table 71 at positions on both sides of the fine movement table 73. The pair of guide members 63 are extended in the scanning direction of the coarse motion table 71. A pair of scanning direction light shielding members 53 and 54 are arranged on the lower surfaces of the pair of guide members 63. The scanning direction light shielding members 53 and 54 are disposed across a pair of guide members 63, and both ends thereof are guided by the guide members 63.

In this embodiment, the same effect as that of the first embodiment can be obtained. However, in this embodiment, since the scanning direction light blocking members 53 and 54 are held on the coarse movement table 71, the fine movement table 73 The weight can be reduced, and the fine movement table 73 can perform a highly accurate positioning operation.
(Supplementary items of the embodiment)
As mentioned above, although this invention was demonstrated by embodiment mentioned above, the technical scope of this invention is not limited to embodiment mentioned above, For example, the following forms may be sufficient.

(1) In the above-described embodiment, an example in which a laser-produced plasma light source is used as a light source of the EUV light 31 has been described. It may be a discharge plasma X-ray source that generates light.
(2) In the above-described embodiment, an example in which the present invention is applied to an EUV light exposure apparatus has been described. However, the present invention can be widely applied to an exposure apparatus that exposes a sensitive substrate with exposure light reflected by a reticle. it can.

It is explanatory drawing which shows 1st Embodiment of the exposure apparatus of this invention. It is explanatory drawing which shows the detail of the wafer stage of FIG. It is explanatory drawing which shows the state which looked at the wafer stage of FIG. 2 from the lower side. It is explanatory drawing which shows the position at the time of the start of the exposure operation | movement of a scanning direction light shielding member, and completion | finish. It is explanatory drawing which shows the wafer stage of 2nd Embodiment of the exposure apparatus of this invention. It is explanatory drawing which shows the state which looked at the wafer stage of FIG. 5 from the lower side.

Explanation of symbols

15, 15A: reticle stage, 19: wafer stage, 33: reticle, 49: moving table, 51: electrostatic chuck, 53, 54: scanning direction light shielding member, 55: fixed blind, 57: non-scanning direction light shielding member, 61 : Wafer, 63: guide member, 71: coarse movement table, 73: fine movement table.

Claims (10)

In an exposure apparatus that scans a reticle stage on which a reticle is arranged and a sensitive substrate stage on which a sensitive substrate is arranged in synchronization, and transfers the reticle pattern of the exposure light reflected by the reticle onto the sensitive substrate.
An exposure apparatus comprising: a scanning direction light-shielding member for limiting an exposure area in the scanning direction of the reticle, which is movably disposed on the reticle stage together with the reticle stage. The exposure apparatus according to claim 1, wherein
An exposure apparatus, wherein the scanning direction light blocking member is disposed so as to be relatively movable with respect to the reticle stage. The exposure apparatus according to claim 1 or 2,
A non-scanning direction light-shielding member for limiting an exposure area of the reticle in the non-scanning direction;
A fixed blind that defines an exposure area of the exposure light;
An exposure apparatus comprising: The exposure apparatus according to claim 3, wherein
An exposure apparatus, wherein an exposure area of the exposure light has an arc shape, and the non-scanning direction light blocking member moves within the arc-shaped exposure area. In the exposure apparatus according to claim 3 or 4,
The exposure apparatus, wherein the scanning direction light shielding member, the fixed blind, and the non-scanning direction light shielding member are arranged in order from the side close to the reticle. The exposure apparatus according to any one of claims 2 to 5,
The reticle stage is
A moving table for moving the reticle in the scanning direction;
An electrostatic chuck disposed on the moving table and attracting the reticle;
Moving means arranged on the moving table to move the scanning direction light blocking member in the scanning direction;
An exposure apparatus comprising: The exposure apparatus according to claim 6.
The exposure apparatus according to claim 1, wherein the moving means includes a pair of guide members that are arranged at positions on both sides of the reticle of the moving table and guide the scanning direction light blocking member in the scanning direction. The exposure apparatus according to any one of claims 2 to 5,
The reticle stage is
A coarse motion table for moving the reticle in the scanning direction;
A fine movement table arranged to be finely movable on the coarse movement table;
An electrostatic chuck disposed on the fine movement table and attracting the reticle;
A moving means disposed on the coarse movement table for moving the scanning direction light blocking member in the scanning direction;
An exposure apparatus comprising: The exposure apparatus according to claim 8, wherein
The exposure apparatus according to claim 1, wherein the moving unit includes a pair of guide members arranged at positions on both sides of the fine movement table of the coarse movement table to guide the scanning direction light blocking member in the scanning direction. The exposure apparatus according to any one of claims 6 to 9,
The exposure apparatus according to claim 1, wherein the electrostatic chuck has an adsorption surface on the lower surface for adsorbing the reticle.

Images