JPH1131653A - Plane position detector and projection aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the surface position information of a wafer and to align the wafer with the focus plane of a projection optical system by controlling the motions of light-projecting means and light-receiving means independently and synchronizing them with the drive of a stage by a driving means and advancing the motion of the light-projecting means to that of the light-receiving means. SOLUTION: An LED is lit in advance just by a time which would elapse until the output of a laser interferometer 14 becomes a stable state. The image of the pinhole of a mask 6 is projected on each measurement point in the first exposed region by light-projecting means 4-8. After it has been recognized that a wafer stage 3 reaches a target position, light-receiving means 9-11 receive the data of a CCD to measure the surface position of each measurement point. The instant the measurement is finished, the LED is turned off and a focus correction position is calculated from a measurement value. Control means 13 inputs the amount of focus correction to stage, a drive means 12 as an instruction signal to correct the focal plane of a projector lens 1 on the wafer 2 and then to expose the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface position detecting apparatus and a projection exposure apparatus using the same, and more particularly, to a step-and-repeat or step-and-scan projection exposure apparatus for manufacturing semiconductor devices, which is mounted on a wafer stage. This is suitable for easily focusing each exposed area of a placed semiconductor wafer (substrate) on a focal plane of a projection lens system (projection optical system) with high throughput.

[0002]

2. Description of the Related Art At present, circuit patterns have been miniaturized in accordance with higher integration of VLSIs, and accordingly, the projection lens system used in a projection exposure apparatus has a higher NA. Accordingly, the permissible depth of focus of the lens system in the circuit pattern transfer process has become narrower. or,
The size of the exposure area to be exposed by the projection lens system also tends to increase.

In order to make it possible to transfer a good circuit pattern over the entire area to be exposed which has been enlarged, it is necessary to ensure that the exposure area of the wafer is within the allowable depth of focus of the projection lens system. It is necessary to position the whole (shot).

In order to achieve this, the position and inclination of the wafer surface with respect to the focal plane of the projection lens system, that is, the plane on which the circuit pattern image of the reticle is focused are detected with high accuracy, and the position and inclination of the wafer surface are adjusted. It becomes important to do it.

As a method of detecting the surface position of the wafer in the projection exposure apparatus, a method of detecting a plurality of surface positions of the wafer surface using an air microsensor and obtaining the position of the wafer surface based on the result, or A light projection type detection optical system (oblique incidence optical system) is used to detect the position shift of the reflection point of the reflected light from the wafer surface as the position shift of the reflected light on the sensor by causing the light beam to enter the surface obliquely. Thus, a method of detecting the surface position of the wafer surface is known.

In many conventional projection exposure apparatuses, the area to be exposed on a wafer is projected onto a projection lens system by moving the wafer stage to a target position by servo driving while measuring the amount of displacement of the wafer stage by a laser interferometer. After the wafer stage is stopped, the surface position of the surface of the region to be exposed is detected by the method described above, and the surface position of the region to be exposed is adjusted. That is, operations such as driving the wafer stage, stopping, detecting the surface position, and adjusting the surface position are sequentially performed.

[0007]

In a detector for detecting the surface position of a region to be exposed on a wafer, a sensor (light receiving element) is used.
The position of the surface of the wafer is detected from information on the incident position of the light beam on the surface. Therefore, when a region to be detected on the wafer stage to be detected is sent to the detection position of the sensor (light receiving element), the detection operation of the surface position of the wafer is started, and at this time, the detection operation is started. At the same time, detection light from the light source is emitted and light reflected from the surface of the wafer is detected.

By the way, as described above, a light emitting element such as an LED is used as the most general light emitting means in the detector. When a light-emitting element such as an LED is continuously operated in a forward direction, crystal defects in a smooth region are multiplied due to an increase in a junction temperature, and the light-emitting characteristics are changed with the lapse of time. Has the drawback of reaching.

For this reason, as a measure for prolonging the service life, a usage method in which the lamp is not turned on except during measurement is adopted. Therefore, when detecting the surface position of the wafer, the LED is turned on at the same time as the start of the detection operation. For example, when a storage type light receiving element such as a CCD is used as a detector, immediately after the LED is turned on. However, since the amount of light detected by the CCD is not stable, a measurement delay is required, such as performing one-scan idle reading after the LED is turned on, and this has been a factor of reducing the throughput.

[0010] Further, when it is necessary to constantly measure with a scanning type projection exposure apparatus or the like, the frequency of replacement is increased due to the life of the LED, which causes a decrease in the up time of the projection exposure apparatus.

The present invention provides high throughput by appropriately setting the operation of a light projecting means for projecting a light beam onto a wafer surface to detect a surface position of a wafer and a light receiving means for receiving a light beam reflected from the wafer surface. It is another object of the present invention to provide a surface position detecting device suitable for manufacturing a device capable of detecting surface position information of a wafer while positioning the wafer with a focal plane of a projection optical system with high accuracy.

Particularly, in the present invention, the light source of the light projecting means is LE.
When a light emitting element such as D is used, the surface position can be detected with high throughput even when the LED is used in a non-lighting mode other than during measurement, and the crystal defect of the LED is constantly used even during measurement. Surface position detection apparatus suitable for manufacturing a device capable of detecting a surface position with high accuracy and high throughput, which suppresses the proliferation of components and reduces the frequency of component replacement due to the life of the LED, and a projection exposure apparatus using the same The purpose is to provide.

[0013]

The surface position detecting device according to the present invention comprises: (1-1) a driving means for feeding an object placed on a stage to or near an image forming plane of a projection optical system; A light projecting means for entering a light beam obliquely with respect to the optical axis of the projection optical system, a light receiving means for receiving reflected light from the object surface, and controlling the operation of the light projecting means and the light receiving means and the light receiving means Detecting the surface position information of the object surface from the signal from, and driving the driving means based on the detection result, and a control means for setting the object surface to a predetermined position, a surface position detection device, The control means controls the operation of the light emitting means and the light receiving means independently of each other, and performs the operation of the light emitting means prior to the operation of the light receiving means in synchronization with the driving of the stage by the driving means. It is characterized by having.

In particular, (1-1-1) the control means starts turning on the light source of the light projecting means at least one cycle before the driving of the object surface starts in synchronization with the servo mechanism of the stage. thing.

(1-1-2) The light projecting means has a mask having one or a plurality of pinholes and an imaging lens for projecting the pinholes of the mask onto the object plane.

(1-1-3) The light receiving means has a detection lens for condensing the light beam reflected from the object surface and a light receiving element for detecting positional information of the reflected light beam condensed by the detection lens. That you are.

(1-1-4) The control means obtains position information of the object surface from information on an incident position of a light beam reflected from the object surface on a light receiving element surface. And so on.

In the projection exposure apparatus of the present invention, (2-1) the wafer surface is set at a predetermined position in the optical axis direction of the projection optical system by using the surface position detecting device having the constitution (1-1), and Is projected and exposed on the wafer surface through the projection optical system.

The method of manufacturing a device according to the present invention is characterized in that (3-1) the device is manufactured through a development processing step on a wafer baked using the projection exposure apparatus having the constitution (2-1). I have.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a reduced-type projection exposure apparatus (projection exposure apparatus using a step-and-repeat method or a step-and-scan method) provided with a surface position detecting device according to the present invention. It is.

In FIG. 1, reference numeral 1 denotes a reduction projection lens system (projection optical system), the optical axis of which is indicated by AX in the figure.
The reduction projection lens system 1 projects the circuit pattern of the reticle R by reducing it, for example, by a factor of 5 to form a circuit pattern image on its focal plane. The optical axis AX is in a relationship parallel to the z-axis direction in the figure.

Reference numeral 2 denotes a wafer (object) having a surface coated with a resist, in which a large number of exposure areas (shots) having the same pattern formed in the previous exposure step are arranged.

Reference numeral 3 denotes a wafer stage (stage) on which the wafer 2 is placed. The wafer 2 is attracted and fixed to the wafer stage 3. The wafer stage 3 has an X stage that moves in the x-axis direction, a Y stage that moves in the y-axis direction, and θ− that rotates around the z-axis direction and an axis parallel to the x, y, and z axes.
It consists of a Z stage. The x, y, and z axis waves are set so as to be orthogonal to each other.

Accordingly, by driving the wafer stage 3, the position of the surface of the wafer 2 is adjusted in the direction of the optical axis AX of the reduction projection lens system 1 and in the direction along a plane orthogonal to the optical axis AX. The inclination with respect to the plane, that is, the circuit pattern image is also adjusted.

Reference numerals 4 to 11 in FIG. 1 denote respective elements of a surface position detecting means including an oblique incidence optical system provided for detecting the surface position and inclination of the wafer 2. Reference numeral 4 denotes a light-emitting diode as a light source for illumination, which is a high-luminance light source such as a semiconductor laser. Reference numeral 5 denotes an illumination lens.

The light emitted from the light source 4 is converted into a parallel light beam by the illumination lens 5, and an aperture mask (hereinafter, also referred to as a "mask") 6 having a single or a plurality of pinholes.
To illuminate. In the figure, three pinholes 6a, 6b, 6c
Is shown.

The plurality of spot lights passing through the respective pinholes of the mask 6 enter the bending mirror 8 via the imaging lens 7, change the direction by the bending mirror 8, and then enter the surface of the wafer 2. doing. At this time, a plurality of spots including the central portion (on the optical axis of the projection optical system 1) of the exposed area of the wafer 2 are illuminated with a plurality of spot lights via the mask 6.

FIG. 2 shows a plurality of exposure areas 10 on the wafer 2 surface.
0, 100a and 100b are shown.

In this embodiment, a plurality of pinholes of the mask 6 are formed at a plurality of locations in the exposure area 100 of the wafer 2 shown in FIG. Here, an imaging lens 7 and a bending mirror 8
Form images of a plurality of pinholes of the mask 6 on the wafer 2.

The luminous flux passing through the plurality of pinholes of the mask 6 irradiates a plurality of locations including the central portion of the exposed area 100 of the wafer 2 and is reflected at each location.

That is, in the present embodiment, a plurality of pinholes are formed in the mask 6, and the positional information of a plurality of measurement points including the central portion in the region to be exposed 100 is measured.

The light beam reflected at each measurement point on the wafer 2 changes its direction by a bending mirror 9 and then enters a position detecting element 11 via a detecting lens 10 on which a light receiving element is two-dimensionally arranged. Here, the detection lens 10 forms an image of the pinhole of the mask 6 on the position detection element 11 in cooperation with the imaging lens 7, the bending mirror 8, the wafer 2, and the bending mirror 9.

That is, the position detecting element 1 of the mask 6 and the wafer 2
1 are optically conjugate with each other. Although schematically shown in FIG. 1, if it is difficult due to the optical arrangement, a plurality of position detecting elements 11 may be separately arranged corresponding to the respective pinholes.

The position detecting element 11 is composed of a two-dimensional CCD or a line sensor, and independently detects the incident positions of a plurality of light beams through a plurality of pinholes on the light receiving surface of the position detecting element 11. Is possible.

Optical axis AX of reduction projection lens system 1 for wafer 2
Since the change in the position in the direction can be detected as a shift in the incident positions of the plurality of light beams on the position detecting element 11, the plurality of measurement points in the exposure area 100 on the wafer 2 in the optical axis AX direction on the wafer surface The position can be detected based on the output signal from the position detecting element 11. Also, the position detecting element 11
Are output to the control means 13 after forming surface position data of each measurement point.

The displacement of the wafer stage 3 in the x-axis and y-axis directions is measured by a known method using a reference mirror 15 and a laser interferometer 14 provided on the wafer stage 3 and indicates the amount of displacement of the wafer stage 3. A signal is input from the laser interferometer 14 to the control means 13 via a signal line. The movement of the wafer stage 3 is performed by stage driving means (driving means) 1
2, the stage driving means 12 receives a command signal from the control means 13 via a signal line, and servo-drives the wafer stage 3 in response to this signal.

In this embodiment, each of the elements 4 to 8 constitutes one element of the light projecting means, and each of the elements 9 to 11 constitutes one element of the light receiving means.

In the present embodiment, the stage driving means 12 has two driving means, a first driving means and a second driving means, and the position (x, y) of the wafer 2 on the plane orthogonal to the optical axis AX by the first driving means. And the rotation (θ) are adjusted, and the position (z) and the inclination (α, α) of the wafer 2 in the optical axis AX direction are adjusted by the second driving means.
β).

The control means 13 includes the stage driving means 1
In addition to the drive control of No. 2, drive commands are also sent to the light source 4 and the position detection element 11 by sending independent command signals via signal lines.

The control means 13 controls the x of the wafer stage 3
The light source 4 is operated during the movement of the wafer stage 3 based on the displacement amounts in the axial and y-axis directions to start emitting a light beam. After the exposure area 100 on the wafer 2 is sent to a target position for aligning with the reticle pattern just below the optical axis AX of the reduction projection lens system 1, the control means 13 outputs an output signal (from the position detection element 11). Is processed by a known method, and the position of the surface of the wafer 2 is detected.

The control means controls the light emitting means and the light receiving means independently of each other. The light emitting means using a light emitting element such as an LED employs a use method in which the light is not turned on after the measurement, and the stage is servo-controlled. In the process of sending the predetermined surface of the flat object (wafer) to the image surface side of the projection optical system and matching the height position with the best focus surface, the predetermined position is synchronized with at least one of the speed servo or the position servo of the stage. LED at least one cycle before the start of focus measurement
By starting the lighting of, there is no need to perform idle reading after the LED is turned on, thereby realizing high throughput.

FIGS. 3, 4 (A) and 4 (B) show the wafer position when the surface position of the region to be exposed 100 on the wafer 2 is detected by the surface position detecting means (4 to 11) in FIG. FIG. 3 is a timing chart illustrating temporal behavior of a stage 3, a light source 4, and a two-dimensional position detecting element 11.

FIG. 3 shows a velocity pattern when the wafer stage 3 is driven by the servo drive to send the area to be exposed (shot) 100 directly below the reduction projection lens system 1. That is, in the present embodiment, the wafer stage 3 starts driving at time T0 such that the first exposure area 100a on the wafer 2 is located directly below the optical axis AX of the reduction projection lens 1, and at time T1, the first stage to be exposed to the reticle pattern. This shows that the alignment of one exposure area 100a is completed.

FIGS. 4A and 4B show surface position detecting means (4 to 4) for detecting the surface position of the exposed area of the wafer 2. FIG.
11) shows the temporal behavior.

A broken line 300 in the figure indicates a time interval required by the CCD accumulation type position detecting element (CCD) 11 for one accumulation, that is, an accumulation period of the CCD 11, and a curve 400 indicates a light source 4 3 shows the response characteristics (light quantity change) of the CCD 11 after the LED light emitting element starts irradiation. Also,
A shaded area 410 represents the time measured by the CCD 11,
Time T4 in FIG. 4A and time T3 in FIG.
This represents the time at which the measurement operation ends and the focus correction operation (surface position driving operation) starts.

As described above, a light-emitting element such as an LED is used in such a way that it is turned on only at the time of measurement as a measure for extending the life.

FIG. 4A shows a conventional method in which the light source 4 and the position detecting element 11 are executed together after the wafer stage 3 is moved to a target position and aligned.

In FIG. 4A, at time T1,
When the start of the irradiation of the light source 4 and the start of the detection of the surface position by the position detecting element 11 are executed simultaneously, as shown by the curve 400, immediately after the LED is turned on (INT3 waveform data), C
The detected waveform is distorted due to the response characteristics of the CD and the measured value is
There is a problem that a delay of at least one CCD accumulation cycle is required, such as using waveform data (eg, INT4) accumulated after time (T1 + ΔT) to generate an error of [μm] degrees.

On the other hand, in the present embodiment, as shown in FIG. 4B, the known delay time (ΔT) is greater than the time T1 at which the movement of the wafer stage 3 to the target position is completed.
By starting irradiation of the LED light-emitting element of the light source 4 with a predetermined current value ahead of time), the measurement value immediately after the LED is turned on is skipped, and the detection operation from time T1, ie, INT3
In this case, the processing using the waveform data described above can be performed, thereby solving the above-described problem of a decrease in throughput.

Thus, if the present invention is implemented in a sequential moving exposure apparatus having a throughput of 70 [sheets / h] and having a CCD accumulation type position detecting element requiring an accumulation cycle of 10 [msec], for example, An improvement in throughput of about 0.8 [sec] per wafer can be expected, and as a result, an improvement in throughput performance of one or more wafers [sheet / h] can be obtained.

In FIG. 4B, the known delay time (Δ
The irradiation of the light source 4 is started earlier by (T time),
Specifically, the delay time known from the well-known speed equation is equal to the moving distance of the servo driven wafer stage 3,
Alternatively, the driving speed is converted into a driving speed and input to the control device 13.

As described above, x of the wafer stage 3
The displacement in the axial and y-axis directions is measured by a known method using a reference mirror 15 provided on the wafer stage 3 and a laser interferometer 14, and a signal indicating the amount of displacement of the wafer stage 3 is output from the laser interferometer 14. Control means 1 via wire
3 has been entered.

Therefore, the control means 13 starts irradiation of the light source 4 in synchronization with at least one of the position servo or the speed servo of the wafer stage 3 and the first light on the wafer 2
The area to be exposed 100a is sent directly below the optical axis AX of the reduction projection lens system 1, and alignment with the reticle pattern is performed. After the positioning is completed, the position detecting element 1
1, the surface position of each measurement point of the area to be exposed 100a is detected by the surface position detecting means (4 to 11) from time T1 after the completion of the alignment. Control means 13 based on the output signal of
Create the surface position data of each measurement point within.

The control means 13 converts the surface position data into a known method (for example, Japanese Patent Application No. 3-153858 or Japanese Patent Application
237900), the distance between the surface position of the first exposed area 100a on the wafer 2 and the reticle pattern image in the optical axis AX direction and the wafer 2
The inclination direction and the amount of inclination are calculated.

A command signal corresponding to the calculation result is input to the stage driving means 12 by the control means 13, and the stage driving means 12 adjusts (corrects) the position and inclination of the wafer 2 on the wafer stage 3 in the direction of the optical axis AX. doing. After the adjustment (correction) of the surface position, the first exposed area 100a is exposed to transfer a circuit pattern image.

After the exposure of the first exposed area 100a is completed, the wafer stage 3 is driven so that the second exposed area 100b on the wafer 2 is located directly below the optical axis AX of the projection lens system 1, and Light source 4 during stage movement
Is started, the surface position of the wafer 2 is detected immediately after the stage movement is completed, and the exposure operation is executed after the focus correction.

FIG. 5 is a flowchart when the conventional surface position detecting device of the present embodiment is implemented. Step 50
At 1, the wafer 2 is loaded onto the wafer stage 3 and fixed to the wafer chuck.

In step 502, the drive of the wafer stage 3 is started, and the wafer stage 3 is moved toward the target position such that the first exposure area 100a on the wafer 2 is directly below the optical axis AX of the projection lens 1.

In step 503, based on the output of the laser interferometer 104, the LE is advanced by a known time from when the LED starts to be turned on to when the LED becomes stable at a predetermined current value.
Lighting of D is started. Specifically, using the well-known speed equation, the above-mentioned time is set to the moving distance of the wafer stage 3,
Alternatively, it is handled after being converted into a driving speed.

An image of the pinhole of the mask 6 is projected onto each measurement point on the first exposed area 100a by the light projecting means (4 to 8).

At step 504, wafer stage 3 reaches the target position. The position information of the wafer stage 3 is obtained from the output from the laser interferometer 14.

At step 505, CCD data is taken in by the light receiving means (9 to 11), and the surface position of each measurement point is measured.

At this time, since the lighting has been started in step 503, the detected waveform data of the CCD is already in a stable state in step 504. A position measurement is performed.

At the same time as the completion of the measurement, the LED is turned off as shown in step 507.

At approximately the same time, as shown in step 507, a focus correction position calculation process is performed from the measured value to detect the focus position.

In step 508, the control means 13 inputs the focus correction amount as a command signal to the stage driving means 12, and performs focus correction driving.

At step 509, the correction driving is completed, and the exposure is performed after the focus planes of the wafer 2 and the projection lens 1 are corrected.

If it is determined in step 510 that all shots have not been exposed, the process proceeds to step 502 and steps 502 to 510 are repeated.

Step 511 upon completion of exposure of the last shot
Then, the wafer 2 is removed from the wafer chuck, and the wafer 2 is carried out.

In the present embodiment, the detection operation of the surface position detecting means (4 to 11) as typified by FIGS. It is characterized by being separated into measurement start operations and controlled independently.
The time loss due to the measurement delay that the conventional surface position detecting means has is eliminated.

In the above embodiment, the irradiation of the light source 4 is started during the movement of the wafer stage 3, and the measurement of the position detecting element 11 is started after the movement of the wafer stage 3 to the target position. The measurement operation may be performed while the wafer stage 3 is moving.

Next, a second embodiment of the present invention will be described. In the present embodiment, the surface position detecting device is applied to a scanning projection exposure device.

In the scanning type projection exposure apparatus, since the focus is corrected during the exposure, for example, during the exposure of the area of 32 mm, the LED is always turned on for about 400 ms. As compared with the above, the junction temperature of the LED frequently increases.

In this case, the average current can be suppressed by pulse lighting to take measures against the above phenomenon. However, if the timing is not synchronized with the accumulation time of the CCD, the amount of received light during the accumulation time is not stable. This appears as distortion of the detected waveform, and as a result, a measurement error occurs.

Therefore, in this embodiment, the control means 13 shown in FIG.
With this configuration, both the high-luminance light source 4 and the position detection element 11 can be controlled independently, and the light emission of the light source 4 and the accumulation timing of the position detection element 11 are synchronized, and the light source 4
The light emission timing is performed in advance. Then, the number of pulse light emission within the accumulation time of the position detecting element 11 is controlled to be constant, and a detection waveform based on a stable received light amount is obtained.

In order to obtain a good detection waveform in the light receiving means of each embodiment, the light emission intensity of the light source 4 is appropriately adjusted according to the surface condition of the exposed area of the wafer 2.

In the present embodiment, the surface information of the region to be exposed on the wafer 2 is acquired in advance in the scanning exposure, and the light emission intensity of the light source 4 is appropriately adjusted according to the surface information.

In the present embodiment, when it is necessary to constantly measure such as during scanning exposure, L
By starting the lighting of the ED and using the lighting operation of the LED under measurement as a pulse lighting mode, the temperature rise of the junction is suppressed, the LED crystal defects are prevented from increasing, and the accumulation of storage elements such as CCDs is prevented. By performing pulse lighting in synchronization with the start operation, highly accurate height position detection is performed without impairing the detection accuracy.

In each of the above embodiments, a two-dimensional position detecting element is used as the position detecting element. However, the same effect can be obtained when a plurality of one-dimensional position detecting elements are arranged. . The light source is not limited to the LED.

Also, a mechanism for focusing the surface of the wafer 2 on the focal plane of the projection lens system is not limited to moving the Z stage of the wafer stage 3 but also changing the focal length of the projection lens system 1 or changing the focal length of the projection lens system. A mechanism for moving the reticle up and down in the direction of the optical axis AX may be employed.

In each of the embodiments described above, a case where the present invention is applied to a reduction type projection exposure apparatus has been described. However, the present invention is directed to a type of exposure apparatus other than the apparatus shown in FIG. The present invention can be similarly applied to an apparatus for projecting, an apparatus for projecting a pattern image by a projection optical system constituted by a lens and a mirror, and the like.

The present invention also relates to an electron beam exposure apparatus for drawing a circuit pattern or projecting a circuit pattern using, for example, an electron beam and an electron lens other than an optical exposure apparatus, and an X-ray exposure apparatus. The same can be applied to the device.

The present invention can be similarly applied to an optical apparatus requiring a surface position detecting device other than the exposure device.

Next, an embodiment of a method of manufacturing a semiconductor device using the above-described projection exposure apparatus will be described.

FIG. 6 is a flowchart of manufacturing a semiconductor device (a semiconductor chip such as an IC or an LSI, or a liquid crystal panel or a CCD).

Step 1 (circuit design) in this embodiment
Now, the circuit design of the semiconductor device will be performed. Step 2
In (mask production), a mask on which a designed circuit pattern is formed is produced.

On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4
The (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer.

The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 4, and includes an assembly process (dicing and bonding) and a packaging process (chip encapsulation). And the like.

In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 7 is a detailed flowchart of the wafer process in step 4 described above. First, in step 11 (oxidation), the surface of the wafer is oxidized. Step 12 (C
In VD), an insulating film is formed on the wafer surface.

In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. Step 15
In (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus to print and expose the circuit pattern of the mask onto the wafer.

In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist are removed. In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the manufacturing method of this embodiment, a highly integrated semiconductor device can be easily manufactured.

[0094]

As described above, according to the present invention, the operation of the light projecting means for projecting a light beam on the wafer surface to detect the surface position of the wafer and the light receiving means for receiving the light beam reflected from the wafer surface are described. A surface position detection device suitable for manufacturing devices that can detect the surface position information of the wafer and accurately align the wafer with the focal plane of the projection optical system while achieving high throughput by appropriately setting it. Can be achieved.

In addition, according to the present invention, when a light emitting element such as an LED is used as the light source of the light projecting means, even when the LED is used in a usage method that does not light except during measurement, the surface position can be determined with high throughput. LE can be detected, and the growth of LED crystal defects can be suppressed even when constant measurement is used.
High accuracy, with reduced frequency of parts replacement due to the life of D
A surface position detection apparatus suitable for manufacturing a device capable of detecting a surface position with high throughput and a projection exposure apparatus using the same can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment when a surface position detection device of the present invention is applied to a projection exposure apparatus.

FIG. 2 is an explanatory diagram showing an arrangement of a region to be exposed (shot) on a wafer;

FIG. 3 is an explanatory diagram of servo drive of the wafer stage according to the first embodiment of the present invention.

FIG. 4 is a timing chart of surface position detection according to the first embodiment of the present invention.

FIG. 5 is a flowchart of surface position detection according to the first embodiment of the present invention.

FIG. 6 is a flowchart of a device manufacturing method according to the present invention.

FIG. 7 is a flowchart of a device manufacturing method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Projection optical system 2 Wafer 3 Wafer stage 4 Light source 5 Illumination lens 6 Mask 7 Imaging lens 8, 9 Mirror 10 Detection lens 11 Position detection element 12 Stage driving means 13 Control means 14 Laser interferometer 100 Exposure area 300 CCD accumulation period 400 CCD response characteristics 410 CCD measurement time R Reticle

Claims (7)

[Claims] 1. A driving means for feeding an object placed on a stage to or near an image forming surface of a projection optical system, and a light projecting device for causing a light beam to enter the object surface in an oblique direction with respect to an optical axis of the projection optical system. Means, light receiving means for receiving light reflected from the object surface,
Controlling the operation of the light emitting means and the light receiving means and detecting surface position information of the object surface from a signal from the light receiving means,
A control unit for driving the driving unit based on the detection result to set the object surface at a predetermined position, wherein the control unit controls the operations of the light projecting unit and the light receiving unit. A surface position detecting device, wherein the operation of the light projecting means is performed prior to the operation of the light receiving means, independently controlled and synchronized with the driving of the stage by the driving means. 2. The apparatus according to claim 1, wherein said control means starts turning on a light source of said light projecting means at least one cycle before starting driving of said object surface in synchronization with a servo mechanism of said stage. 1. Surface position detecting device. 3. The light emitting device according to claim 2, wherein said light projecting means includes a mask having one or a plurality of pinholes, and an imaging lens for projecting the pinholes of said mask onto said object plane. 1. Surface position detecting device. 4. The light receiving means includes a detection lens for condensing a light beam reflected from the object surface and a light receiving element for detecting positional information of the reflected light beam condensed by the detection lens. The surface position detecting device according to claim 1. 5. The apparatus according to claim 1, wherein said control means obtains position information of the object surface from information on an incident position of a light beam reflected from the object surface on a light receiving element surface. 2. The surface position detecting device according to claim 1. 6. A wafer position is set at a predetermined position in a direction of an optical axis of a projection optical system by using the surface position detection device according to claim 1, and a pattern on a reticle surface is projected by the projection optical system. A projection exposure apparatus, which performs projection exposure on a wafer surface via a system. 7. A method for manufacturing a device, comprising manufacturing a device through a development processing step on a wafer printed using the projection exposure apparatus according to claim 6.