JP2513281B2 - Alignment device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an alignment apparatus, for example, in an exposure apparatus for manufacturing a semiconductor element, on a first object plane such as a mask or a reticle (hereinafter referred to as “mask”). The present invention relates to a positioning device suitable for performing relative positioning (alignment) between a mask and a wafer when exposing and transferring a fine electronic circuit pattern formed on a second object surface such as a wafer. .

(Prior Art) Conventionally, in an exposure apparatus for manufacturing a semiconductor, relative alignment between a mask and a wafer has been an important factor for improving performance. Especially in the alignment of the recent exposure apparatus, in order to achieve high integration of semiconductor elements,
For example, one having a positioning accuracy of submicron or less is required.

In many alignment devices, a so-called alignment pattern for alignment is provided on the mask and wafer surfaces, and the alignment of both is performed using the positional information obtained from them. As the alignment method at this time, for example, the deviation amount of both alignment patterns can be detected by performing image processing, or the alignment can be performed as proposed in U.S. Pat. No. 4037969 or JP-A-56-157033. This is performed by using a zone plate as a pattern, irradiating the zone plate with a light beam, and detecting the position of the light condensing point on a predetermined surface of the light beam emitted from the zone plate at this time.

In general, an alignment method using a zone plate has a feature that relatively high-precision alignment can be performed without being affected by a defect in the alignment pattern, as compared with a method using a simple alignment pattern.

FIG. 20 is a schematic view of a conventional alignment device using a zone plate.

In the figure, the parallel light flux emitted from the light source 72 passes through the half mirror 74, is condensed by the condenser lens 76 at the condensing point 78, and is then placed on the mask alignment pattern 68a on the mask 68 surface and the support 62. The wafer alignment pattern 60a on the surface of the formed wafer 60 is irradiated. These alignment patterns 68a, 60a are composed of reflective zone plates,
Condensing points are formed on a plane orthogonal to the optical axis including the converging points 78. At this time, the amount of deviation of the position of the condensing point on the plane is guided by the condensing lens 76 and the lens 80 onto the detection surface 82 to be detected.

Then, based on the output signal from the detector 82, the control circuit 84
In this way, the drive circuit 64 is driven to position the mask 68 and the wafer 60 relative to each other.

FIG. 21 shows the mask alignment pattern shown in FIG.
FIG. 68 is an explanatory diagram showing an imaging relationship of light fluxes from 68a and the wafer alignment pattern 60a.

In the figure, a part of the light beam diverging from the condensing point 78 is diffracted by the mask alignment pattern 68a, and a condensing point 78a indicating the mask position is formed in the vicinity of the condensing point 78.
The other part of the light flux passes through the mask 68 as zero-order transmitted light and is incident on the wafer alignment pattern 60a on the surface of the wafer 60 without changing the wavefront. At this time, the light beam is diffracted by the wafer alignment pattern 60a, and then again passes through the mask 68 as 0th-order transmitted light and is condensed near the condensing point 78 to form a condensing point 78b representing the wafer position. In the figure, when the light beam diffracted by the wafer forms a converging point, the mask 68 acts as a simple transparent state.

The position of the converging point 78b due to the wafer alignment pattern 60a formed in this way is determined according to the deviation amount Δσ of the wafer 60 with respect to the mask 68 along the plane orthogonal to the optical axis including the converging point 78. Deviation amount Δ corresponding to Δσ
formed as σ ′.

In such a method, when the wafer surface is inclined with respect to the reference surface such as the mask surface or the mask holder surface in the semiconductor exposure apparatus, and the ground surface of the exposure apparatus, the center of gravity of the light flux incident on the sensor is measured. Changes and causes an alignment error.

In general, providing an absolute coordinate system on a sensor and setting its reference origin is due to other alignment error factors, such as inclination having a warpage or deflection of a wafer surface, fluctuation of the center of gravity of a light beam due to uneven coating of resist, alignment light source. There is a problem that it is very difficult to set the origin with high accuracy due to fluctuations in the oscillation wavelength, oscillation output, light beam emission angle, fluctuations in sensor characteristics, fluctuations due to repeated alignment head positions, and the like.

(Problems to be Solved by the Invention) The present invention provides a first signal light as means for removing an error factor in detecting a deviation amount when aligning a first object such as a mask and a second object such as a wafer. In addition to the alignment light flux as the second light flux, an alignment light flux as the second signal light is formed by diffracted light from a linear grating lens of an order different from that of the first signal light, and by using these signal light, high precision is achieved. An object of the present invention is to provide a positioning device capable of positioning.

Particularly, in the present invention, the action of the center of gravity movement on the sensor with respect to the inclination of the wafer surface of the second signal light flux is made to be completely equal to that of the first signal light flux, and the second signal is also applied to the fluctuation of the position of the alignment head. The light flux is set so as to be subjected to the action of moving the center of gravity which is exactly the same as that of the first signal light flux, so that the relative position fluctuations of the second signal light flux and the first signal light flux on the sensor are theoretically different between the mask and the wafer. It is an object of the present invention to provide a position aligning device capable of performing highly accurate position adjustment by relying only on the position deviation of.

(Means for Solving the Problems) When the first object and the second object are opposed to each other and relative positioning is performed, physical optical elements are formed on the first object surface and the second object surface, respectively. Then, diffracted light generated when light is incident on one of the physical optical elements is incident on the other physical optical element, and the light quantity distribution of the diffraction pattern generated on the predetermined surface by the other physical optical element is detected. When the relative positioning of the first object and the second object is performed by detecting the physical object, one physical optical element A of the two physical optical elements is composed of a linear grating lens, and This is so configured that the light fluxes of different diffraction orders emitted from the optical element A have a convex lens action and a concave lens action at the same time.

In particular, in the present invention, the other physical optical element B of the first or second physical optical element is composed of two alignment marks, first and second alignment marks B1 and B2 for the first and second signals, Two diffracted lights of different orders generated from the physical optical element A are made incident on the first and second alignment marks B1 and B2, and the light flux centroids of the diffracted lights from the first and second alignment marks B1 and B2 are determined. Two diffracted light beams from the physical optical element A are detected by the first and second detection units, or conversely, the diffracted light beams from the first and second alignment marks B1 and B2 are made incident on the physical optical element A. Is characterized by detecting the center of gravity of the light flux by the first and second detection units and using the output signals from the first and second detection units to position the first object and the second object. There is.

In addition, the present invention is characterized in that the respective elements are set so that the positions of the center of gravity of the light beams on the predetermined surface of the two diffracted lights are displaced in the directions opposite to each other with respect to the positional deviation between the first object and the second object. There is.

(Embodiment) FIG. 1 is a schematic view of a main part of a first embodiment of the present invention, and FIG. 2 is a schematic view of a main part when the optical path of FIG. 1 is expanded.

In the figure, 1 is a first object, for example, a mask. Reference numeral 2 is a second object, for example, a wafer aligned with the mask 1.
Reference numerals 3 and 4 denote first and second physical optical elements for alignment, which are provided on the surfaces of the first object 1 and the second object 2, respectively.

The first physical optical element 3 is composed of first and second alignment marks 3a and 3b for the first and second signals, and the second physical optical element 4 is composed of a linear grating lens.

In FIG. 1, the light flux from the light source 8 is projected as parallel light by the projection lens 9 onto the first and second alignment marks 3a and 3b. Then, the diffracted light beam of the predetermined order diffracted by the alignment marks 3a, 3b is further diffracted by the alignment mark 4, and the −1st order diffracted light 6 of the diffracted light is detected by the sensor.
The + 1st-order diffracted light 7 is incident on the sensor 5b at 5a. Then, the spot position information of the diffracted light is processed by a processing system 10 including a processing circuit, a position deviation control signal of the first object 1 and the second object 2 is obtained, and the controller 11 moves the stage 12 based on the signal, An alignment system that sets the first object 1 and the second object 2 to predetermined positions is configured.

In FIG. 1, the X direction is the alignment direction,
The lens action is applied only in this direction to the first and second lenses of the physical optical element 3.
The alignment marks 3a and 3b are provided. In the in-plane YZ orthogonal to the alignment direction, the alignment marks 3a and 3b have a curved pattern because they have a function of deflecting the incident and outgoing angles. Of these, the first alignment mark 3a has a convex power and the second alignment mark 3b has a concave p.
The marks have opposite signs of curvature so that the ower is held in the alignment direction.

On the other hand, the alignment mark 4 which is the second physical optical element
Consists of a linear grating lens. It has a convex power and a concave power depending on whether the order is positive or negative. The chief ray of the diffracted light of each order at this time is in the same direction as the incident light.

In this embodiment, a reflection type physical optical element is used,
The alignment lights 6 and 7 are reflected and diffracted toward the sensors 5a and 5b, respectively, corresponding to the directions diffracted by the second alignment marks 3a and 3b.

Next, the principle of the alignment apparatus shown in FIG. 1 and the features of the configuration will be described with reference to FIG.

FIG. 2 is a schematic diagram showing a projection component on a plane orthogonal to the incident plane, in which the optical system is developed along the light flux and the light flux passing through the center of each alignment mark in the embodiment of FIG.

In FIG. 2, the first and second alignment marks 3a and 3b on the surface of the first object 1 and the alignment mark 4 on the surface of the second object 2 each have a one-dimensional lens action (there is power only in the plane of the drawing). It is a physical optical element, and the alignment light beam is diffracted as shown in the figure. That is, the parallel incident light is condensed by the first alignment mark 3a at the position indicated by the point F ₁ and is condensed by the second alignment mark 3b at the point F ₂ . On the other hand, the alignment mark 4 has a function of forming an image of the points F ₁ and F ₂ on the sensor surface 5 by the lens action of the diffraction orders of different signs (here, + 1st order and −1st order). The distance between the first object 1 and the second object 2 is g, and the distance between the second object 2 and the sensor 5 is L.
The focal lengths of the alignment marks 3a and 3b are f ₁ and f ₂ , respectively.

Further, the relative positional deviation amount between the first object 1 and the second object 2 is ε, and the displacement amounts from the coincident state of the center of gravity of the signal light flux at that time are S ₁ and S ₂ , respectively. Displacement S ₁ and S ₂ of the signal light beam centroid is determined geometrically as the intersection of the straight line and the detection surface 5 bear the optical axis center of the alignment marks 3a, the focal point of 3b F _1, F ₂ and the alignment mark 4. Therefore, the first object 1 and the second object 2
Displacements S ₁ and S ₂
The diffraction orders are selected so that the signs of the image forming magnifications by the alignment marks 4 are opposite to each other in order to obtain the above.

For example, the displacement amounts S ₁ and S ₂ at this time can be quantitatively shown as follows.

Here, the focal lengths f ₁ and f ₂ are given the functions of a convex lens and a concave lens such that f ₁ is positive and f ₂ is negative as shown in the figure, and the distance L is sufficient (compared to f ₁ and f ₂ ). If the value is large, the position shift of the center of gravity of the signal light beam is enlarged and the positions move in opposite directions.

The difference ΔS between the spot positions on the sensor 5 surface is ΔS = S ₂ −S ₁
given that Becomes

Further, when the alignment mark 4 is of a reflective type, it can be obtained similarly. That is, at this time, the alignment mark 4 and the subsequent parts shown in FIG. 2 may be folded back symmetrically with respect to the alignment mark 4.

Next, a case where the second object 2 is inclined by a small amount β will be described.
All the light beams emitted from the alignment mark 4 are inclined at an angle 2β according to the law of reflection. If the distance L is sufficiently large, the amount of movement of the spot accompanying this inclination is Sβ.
= 2βL. The spot position on the surface of the sensor 5 changes in both the concave and convex type and the concave and convex type, and S ₁ ′ = S ₁ + 2βL S ₂ ′ = S ₂ + 2βL ΔS ′ = S ₂ ′ + S ₁ ′ = S ₂ −S ₁ = ΔS, It can be seen that the spot position difference ΔS does not depend on the inclination.

In this embodiment, the movement of the signal light beam on the surface of the sensor 5 S ₁ , S ₂
Is expressed by the equations (1) and (2), and if f ₁ = 430 μm f ₂ = −370 μm g = 30 μm L = 40 000 μm, = 101ε, and if the difference signal S ₂ −S ₁ is taken, then S ₂ −S ₁ = (101 + 99) ε = 200ε.

That is, it is possible to detect with a sensitivity of 200 times the positional deviation ε between the first object 1 and the second object 2.

Now, assuming that the resolution of the sensor 5 is 1 μm, 0.005 μm
It is possible to detect the positional deviation of.

When the first object 1 is used as a mask and the second object 2 is used as a wafer and is applied to alignment in a proximity exposure apparatus, it is better to use a linear grating lens as the alignment mark 4 on the wafer 2 as in the present embodiment. It is preferable to consider deformation due to In addition, the first object 1 side may be used as a linear grating lens, depending on the case.

In this embodiment, the linear grating lens is provided on the second object plane, but the linear grating lens is provided on the first object plane and the first and second signals are provided on the second object plane. Even if the first and second alignment marks are provided, the object of the present invention can be achieved in the same manner as described above.

As shown in FIG. 1, the arrangement state of the first and second alignment marks for the first and second signals provided on the first object or the second object plane is the alignment direction of the first object and the second object ( x
Direction) and a direction orthogonal to the direction) or a parallel direction. Further, they may be arranged in the same region in an overlapping manner.

FIG. 3 is a schematic view of the essential parts of a second embodiment of the present invention, and FIG. 4 is a schematic view of the essential parts when the optical path of FIG. 3 is expanded.

In this embodiment, the first and second alignment marks 3a and 3b provided on the surface of the first object 1 are arranged in the alignment direction (x direction). The first, as shown in FIG. 4, the second alignment marks 3a, the optical axis of 3b is the mark boundaries are set so as to condense light at the position of each point F _1, F _2. The movement of the light beam on the surface of the sensor 5 is the same as in the first embodiment.

FIG. 5 is a schematic view of the essential parts of a third embodiment of the present invention, and FIG. 6 is a schematic view of the essential parts when the optical path of FIG. 5 is expanded.

In this embodiment, the physical optical element 3 on the surface of the first object 1 is constructed by superposing the first alignment mark 3a acting as a convex lens and the second alignment mark 3b acting as a concave lens.

As shown in FIG. 6, the optical axes of the first and second alignment marks are at the center of the mark, and they function as a convex lens and a concave lens, and the light flux is set to be focused at points F ₁ and F ₂ .
The movement of the light beam on the surface of the sensor 5 is the same as in the first embodiment.

FIG. 7 is a schematic view of the essential parts of a fourth embodiment of the present invention, and FIG. 8 is a schematic view of the essential parts when the optical path of FIG. 7 is expanded.

In this embodiment, the light beam from the light source 8 is projected as parallel light by the projection lens 9 onto the second physical optical element 4 on the second object 2 in advance. The reflected diffracted light from the second physical optical element 4 is transmitted to the first physical optical element on the surface of the first object 1.
The light is incident on the first and second alignment marks 3a and 3b, and diffracted light of a predetermined order from the first alignment marks 3a and 3b is detected by the sensors 5a and 5b. The second physical optical element 4 on the surface of the second object 2 is composed of a linear grating lens, and the incident parallel light beam is diffracted, of which the + _{1st order} diffracted light is focused on the focus F ₁ and the −1st order diffracted light is the focus.
Focused on F ₂ . The focal lengths at this time are f ₁ and −f, respectively.
_{Is 1} . The first alignment mark 3a on the first object 1 acts as a concave lens so that the light beam focused at the point F ₁ is imaged on the surface of the sensor 5a, and the second alignment mark 3b is at the point.
It has a function of a convex lens so that the light beam focused on F ₂ is imaged on the surface of the sensor 5b.

The relative positional deviation amount between the first object 1 and the second object 2 is −ε, and the displacement amounts S ₁ and S ₂ of the signal light beam positions at that time are the focal points on the surface of the sensor 5 of the points F ₁ and F ₂ , respectively. If SS ₁ and SS ₂ are
The second alignment marks 3a, the optical axis center and the point F ₁ of 3b, is as follows if Shimese quantitatively prompts geometrical optics as the intersection between the straight line and the detection surface 5 connecting the point F _2.

Now, if f ₁ = 400 μm L = 40 000 μm g = 30 μm, If the difference signal S ₂ −S ₁ is taken, then S ₂ −S ₁ = −93ε−108ε = −201ε, and for the positional shift ε between the first object 1 and the second object 2,
It can be detected with a sensitivity of 201 times.

FIG. 9 is a schematic view of a main part of an embodiment when the alignment apparatus of the fourth embodiment of FIG. 7 is applied to an exposure apparatus for manufacturing a proximity type semiconductor.

In FIG. 9, a light projecting system and a light receiving system are an alignment light source 8, a light projecting lens 9, a projection mirror 17, sensors 5a and 5b, and a big up head 1 in which processing circuits 10a and 10b are integrated.
It is housed in 6 and can be moved to the alignment mark position by a stage (not shown). The alignment light beam projected from the big-up head 16 passes through the mask 1, which is the first object supported by the mask holder 15, and is a wafer alignment mark on the wafer 2, which is the second object supported by the wafer stage 12. 4 and then diffracted by the outgoing alignment mark 3 on the surface of the mask 1 which is the first object and again received by the pass sensors 5a and 5b to the big-up head 16. The spot information of the diffracted light beam received by the sensors 5a and 5b passes through the processing circuits 10a and 10b,
The exposure system controller 14 recognizes it as alignment information of the mask 1 and the wafer 2. At this time, the wafer stage 12 is moved to the optimum position, and a movement signal is sent to the stage controller 11 for exposure, and the wafer stage 12
To move.

When the alignment is completed, the exposure beam is projected onto the exposure area indicated by E, and the printing is completed. At this time, the alignment light constitutes the oblique projection system and the oblique light reception system, and the retracting operation is not required.

FIG. 10 is a schematic view of the essential parts of a fifth embodiment of the present invention, and FIG. 11 is a schematic view of the essential parts when the optical path of FIG. 10 is expanded.

In this embodiment, similarly to the fourth embodiment of FIG. 7, the second object 2
The alignment light 4 is first projected onto the upper alignment mark 4, and the reflected diffracted light is incident on the first and second alignment marks 3a and 3b on the first object 1, and the diffracted light is detected by the sensor 5
It constitutes the detection system with a and 5b. The first on the first object 1
The second alignment marks 3a and 3b are arranged in the alignment direction.

As shown in FIG. 11, the first and second alignment marks 3a, 3
The optical axis of b is on the mark boundary and is set so as to collect light at the positions of points F ₁ and F ₂ , respectively, and the movement on the surface of the sensor 5 is the same as in the fourth embodiment.

FIG. 12 is a schematic view of the essential parts of a sixth embodiment of the present invention, and FIG. 13 is a schematic view of the essential parts when the optical path of FIG. 12 is expanded.

In the present embodiment, the incident position of the alignment light flux on the sensor surface 5 when there is no relative displacement between the first object 1 and the second object 2 is defined by the alignment direction passing through the center of the alignment mark, the vertical cross section, and the sensor surface. It forms a system twisted by a length Sc from the light beam.

The alignment mark 4 on the second object 2 and the condensed state of the diffracted light thereof are the same as those in the fourth embodiment, and the alignment marks 3a and 3b on the first object 1 are deflected so that It is set so that the signal light beam comes to the position S ₀ which is displaced by the distance Sc on the sensor surface 5 in the state where the second object 2 is not displaced.

The signal light beams move in opposite directions with respect to this point S ₀ as a result of displacement ε between the first object 1 and the second object 2, and
S ₁ and S ₂ are the same as in the fourth embodiment.

FIG. 14 is a schematic view of the essential parts of a seventh embodiment of the present invention, and FIG. 15 is a schematic view of the essential parts when the optical path of FIG. 14 is expanded.

In this embodiment, the incident position of the alignment light beam on the sensor surface 5 when there is no displacement between the first object 1 and the second object 2 is
From the intersection line of the sensor surface and the cross section perpendicular to the alignment direction passing through the center of the alignment mark, the two systems, the uneven system and the uneven system, are twisted by amounts different from the distances S ₀₁ and S ₀₂ , respectively, and S _off = S
_02- S ₀₁ is added with an offset. The alignment mark 4 on the second object 2 and the condensed state of the diffracted light thereof are the same as those in the fourth embodiment, and the alignment marks 3a and 3b on the first object are added with a deflecting action so that the first object 1 It is set so that the signal light beams come to the positions S ₀₁ and S ₀₂ on the sensor surface 5 which are displaced by the distances S _c1 and S _c2 , respectively, in the state where the two objects 2 are not displaced.

The signal light beams move in opposite directions with respect to the point S ₀₁ and the point S _{02 in accordance} with the positional deviation ε between the first object 1 and the second object 2, and their amounts S ₁ and S ₂ are the same as those in the fourth embodiment. Is the same as.

FIG. 16 is a schematic diagram of the essential part of the eighth embodiment of the present invention, and FIG. 17 is a schematic diagram of the essential parts when the optical path of FIG. 16 is expanded.

In this embodiment, the first and second alignment marks 3a and 3b on the surface of the first object 1 are arranged in the alignment direction (x direction).

The optical axes of the first and second alignment marks 3a and 3b are at the centers of the respective alignment marks, and the optical axis shift from the alignment mark 4 on the surface of the second object 2 causes a shift on the surface of the sensor 5, resulting in the first The signal light flux comes to the positions of the points S ₀₁ and S ₀₂ on the sensor 5 in a state where there is no positional deviation between the object 1 and the second object 2.

The signal light beams move in opposite directions with respect to the point S ₀₁ and the point S _{02 in accordance} with the positional deviation ε between the first object 1 and the second object 2, and their amounts S ₁ and S ₂ are the same as those in the fourth embodiment. Similar to the example.

FIG. 18 is a schematic view of the essential parts of a ninth embodiment of the present invention, and FIG. 19 is a schematic view of the essential parts when the optical path of FIG. 18 is expanded.

In this embodiment, the first physical optical element 3 on the first object 1 surface and the second physical optical element 3
The second physical optical element 4 on the surface of the object 2 constitutes an offset of two systems, an uneven system and a concave-convex system, by the alignment mark 4 formed of the linear grating lens on the second object 2. Alignment mark 4 on the second object 2
The light beam incident on is diffracted into two light beams having wavefronts that are condensed at the positions of points F ₁ and F ₂ . The points F ₁ and F ₂ are points twisted from the normal line at the center of the alignment mark, and are the optical axis centers of the first and second alignment marks 3a and 3b on the first object 1 and these points. The signal light beams in the direction connecting the two are at different positions on the sensor surface 5 like points S ₀₁ and S ₀₂ .

The signal light beams move in opposite directions with respect to the point S ₀₁ and the point S _{02 in accordance} with the positional deviation ε between the first object 1 and the second object 2, and their amounts S ₁ and S ₂ are the same as those in the fourth embodiment. Similar to the example.

(Effect of the Invention) According to the present invention, the first and second physical optical elements having the above-described optical properties are formed on the first object such as a mask for performing alignment and the second object surface such as a wafer, One of the physical optical elements is composed of a linear grating lens element, which allows two detection systems of different orders to
By setting so that the diffracted lights on the predetermined surface have opposite signs to each other's displacement amount, a positioning device having the following effects is achieved.

(A) Even if the position of the center of gravity of the alignment light fluctuates due to the tilt of the wafer surface, the unevenness of resist coating, or the local tilt such as warpage that occurs during the exposure process, the relative alignment of the two alignment signal lights By detecting the position of the center of gravity, the positional deviation can be accurately detected without being influenced by the inclination of the wafer surface.

(B) Since the position of the alignment head changes relative to the mask, even if the position of the center of gravity of the alignment signal light on the sensor changes, the relative position of the center of gravity of the two alignment signal lights is detected. , It is not affected by misalignment of the alignment head.

(C) Two systems can be constructed with the same alignment mark, the total magnification can be effectively obtained, and an alignment signal having about twice the sensitivity can be obtained as compared with the case where each system is used alone. it can.

(D) It is possible to configure two systems using the linear grating lens, the alignment mark is simplified, and it is easy to create.

(E) Since the linear grating lens is used, the tolerance in the direction orthogonal to the alignment is large.

[Brief description of drawings]

1st, 3rd, 5th, 7th, 10th, 12th, 14th, 16th, and 18th are schematic diagrams of the essential parts of the 1st to 9th embodiments of the present invention, and 2nd and 4th. , 6th, 6th
8, 11, 13, 13, 15, 17 and 19 are schematic views of essential parts when the optical paths of the first to ninth embodiments of the present invention are developed in order, and FIG. 9 is a fourth view of the present invention. A schematic view of a main part of one embodiment when the embodiment is applied to an exposure apparatus for manufacturing a proximity type semiconductor,
20 and 21 are schematic views of a conventional alignment device. In the figure, 1 is a first object, 2 is a second object, 3 and 4 are first and second physical optical elements, 3a and 3b are first and second alignment marks, and 5,5a and 5b are sensors, Reference numerals 6 and 7 are diffracted lights, 8 is a light source, 9 is a projection lens, 10, 10a and 10b are processing circuits, 11 is a stage controller, 12 is a wafer stage, 14 is an exposure system controller, and 15 is a mask holder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-1-233305 (JP, A) JP-A-1-285804 (JP, A) JP-A-1-209305 (JP, A) JP-A-1- 209304 (JP, A) JP-A-1-207605 (JP, A) JP-A 64-106427 (JP, A) JP-A 64-63802 (JP, A) JP-A 64-55824 (JP, A) JP-A-64-55823 (JP, A) JP-A-63-247602 (JP, A) JP-B-54603 (JP, B2)

Claims (2)

(57) [Claims] 1. When a first object and a second object are opposed to each other for relative positioning, physical optical elements are respectively formed on the first object surface and the second object surface, and one of them is formed. By diffracting light generated when light is incident on the physical optical element of 1 is incident on the other physical optical element, and detecting the light amount distribution of the diffraction pattern generated on the predetermined surface by the other physical optical element by the detection means. , When performing relative positioning between the first object and the second object, one of the two physical optical elements A is formed by a linear grating lens, and the physical optical element A emits light. An aligning device characterized in that it is configured to have a convex lens action and a concave lens action at the same time for light beams of different diffraction orders. 2. The other physical optical element B of the two physical optical elements is provided with first and second alignment marks B1 and B for signals.
2 alignment marks, and by combining the physical optical element A and the physical optical element B, two alignment systems, an uneven system and a concave-convex system, are formed, and diffraction from the two alignment systems is used. The alignment device according to claim 1, wherein the first object and the second object are positioned relative to each other.