JPH07130640A - Position detector and manufacture of semiconductor element using same - Google Patents

Abstract

PURPOSE:To detect the positions of a mask and a wafer with high precision, by obtaining the relative position deviation of a mask and a wafer in a plane, and simultaneously obtaining the interval and the deviation amount of a light casting means and the mask. CONSTITUTION:The interval of a mask 1 and a wafer 2 is (g), and the position deviation amount is (w). The position deviation amount of a light casting means and the mask 1, which are arranged so as to face each other, is known. Position data Y from a detection means are previously obtained concerning various cases, and a multiple regression formula is obtained and stored in a recording means. When both positions are practically detected, the position data from the detection means and the general formula recorded in the recording means are used, and the relative position detection is performed with high precision, while the influence of error factors such as aberration and manufacture error of a detection system and change of oscillation wavelength of a semiconductor laser with time are excluded. Thereby a position detector of high precision can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device and a method of manufacturing a semiconductor device using the position detecting device. For example, in an exposure apparatus for manufacturing a semiconductor device, a first mask, reticle (hereinafter referred to as "mask") or the like. This is suitable for performing relative positioning between the mask and the wafer when the fine electronic circuit pattern formed on the object surface is transferred by exposure onto the second object surface such as the wafer.

[0002]

2. Description of the Related 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. Particularly in the recent alignment of an exposure apparatus, one having a positioning precision of, for example, submicron or less is required for high integration of semiconductor elements.

In many alignment devices, a so-called alignment pattern for alignment is provided on the mask and wafer surfaces, and the positional information obtained from them is used to
Both are aligned. As an alignment method at this time, for example, a deviation amount of both alignment patterns is detected by performing image processing, or US Pat. No. 4037969 or JP-A-56-15703.
As proposed in Japanese Patent Laid-Open No. 3 publication, a zone plate is used as an alignment pattern, the zone plate is irradiated with a light beam, and at this time, the position of a condensing point on a predetermined surface of the light beam emitted from the zone plate is detected. ing.

Generally, 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. 11 is a schematic view of a conventional alignment device using a zone plate.

In the figure, the parallel light beam emitted from the light source 72 passes through the half mirror 74, and is converged by the condensing lens 76 at the converging point 78. Then, the mask alignment pattern 68a on the surface of the mask 68 and the support 62. The wafer alignment pattern 60a on the surface of the wafer 60 placed on the wafer is irradiated. These alignment patterns 68a and 60a are composed of reflection type zone plates, and each form a condensing point on a plane including the condensing point 78 and orthogonal to the optical axis. 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.

Based on the output signal from the detector 82, the control circuit 84 drives the drive circuit 64 to position the mask 68 and the wafer 60 relative to each other.

FIG. 12 shows the mask alignment pattern 68a and the wafer alignment pattern 60a shown in FIG.
It is explanatory drawing which showed the imaging relationship of the light beam from.

In the figure, a part of the light beam diverging from the converging 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 converging point 78. Also, the other part of the light flux is mask 6
8 as the 0th-order transmitted light, and the wafer 6 without changing the wavefront
It is incident on the wafer alignment pattern 60a on the 0 plane. At this time, the luminous flux is the wafer alignment pattern 60a.
After being diffracted by, the mask 68 is again transmitted as the 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, the wafer 60
When the light beam diffracted by the light beam forms a converging point, the mask 68 acts as a simple transparent state.

The position of the condensing point 78b formed by the wafer alignment pattern 60a formed in this manner is along a plane orthogonal to the optical axis including the condensing point 78 in accordance with the deviation amount Δσ of the wafer 60 with respect to the mask 68. It is formed as a shift amount Δσ ′ corresponding to the shift amount Δσ.

Conventionally, the amount of deviation Δσ ′ at this time is detected and the mask 68 and the wafer 60 are aligned with each other.

[0012]

The alignment device shown in FIG. 11 has the following problems.

Since the amount of deviation Δσ ′ depends on the amount of deviation Δσ, the gap g, the positional relationship between the light projecting means and the mask, and the amount of pitching, rolling, yawing, etc. of the wafer with respect to the mask, one deviation amount Δσ A number of sets of variables (hereinafter also referred to as “explanatory variables”) indicating the positional relationship such as the displacement amount Δσ and the interval g correspond to ′. Therefore, if it is attempted to detect the matching state at the position of the converging point 78a,
At the time of non-focusing, for example, if the light beam is condensed at the position of the converging point 78b, the displacement amount Δσ cannot be accurately determined even if the value of the displacement amount Δσ ′ is accurately measured. For this reason, it is necessary to perform the alignment operation once, but twice or three times, and the throughput decreases.

The present invention solves an error factor that occurs when detecting the position of a first object such as a mask and a second object such as a wafer, and enables a highly accurate and easy alignment. It is an object of the present invention to provide a position detecting device and a method for manufacturing a semiconductor device using the position detecting device.

[0015]

The present invention includes a first object and a second object.
The amount of relative positional displacement of the object (hereinafter simply referred to as "displacement amount")
Also called. ) Is calculated at the same time as the distance, the amount of deviation between the light projecting means and the mask, and the like, and the position of the first object and the second object is detected with high accuracy.

(1-1) The position detecting device of the present invention is the first
Physical optical elements are provided on the object plane and the second object plane respectively, and light beams are made incident on these physical optical elements from a light projecting means to detect position information of a diffracted light beam of a predetermined order generated on a predetermined surface of the light beam. At least the same as the number of multiple regression equations based on the relative positional relationship between the first object and the second object when the relative position between the first object and the second object is detected by detecting by means. The number of positions of the diffracted light is generated and k × n (where k and n are positive integers) positional deviation amounts and intervals between the first object and the second object and k × n diffracted light. Position information and k multiple regression equations are obtained, and a maximum of k positional deviations between the first object and the second object are calculated from the k multiple regression equations and the position information of k diffracted light. It is characterized in that the value of the interval is calculated by the calculating means and the signal from the calculating means is used.

In particular, it has frequency changing means for changing the frequency of the light beam from the light projecting means, and divides a part of the diffracted light from the physical optical element to guide it onto a predetermined surface. It is characterized in that it is illuminating, and that a regression equation is obtained with the positional shift amount of the physical optical element on the second object plane as the positional shift amount between the first object and the second object.

(1-2) In the method of manufacturing a semiconductor device according to the present invention, after the relative position between the mask and the wafer is detected, the pattern on the mask surface is transferred to the wafer surface, and the wafer is subjected to a developing treatment step. When manufacturing a semiconductor device via
At least the same number of position information pieces of diffracted light as the number of multiple regression equations based on the relative positional relationship between the object and the second object are generated, and k × n (where k and n are positive integers) The k multiple regression equations and the k diffracted light beams are obtained by obtaining k multiple regression equations from the amount of positional deviation or distance between the first object and the second object and the position information of the k × n diffracted light beams. Position information and up to k of the first
It is characterized in that the positional deviation amount between the object and the second object and the value of the distance are obtained by the calculating means, and the signal from the calculating means is used.

[0019]

EXAMPLE An example of the present invention will now be described. To simplify the description, the positional relationship between the first object and the second object is shown.
Among the plurality of variables, the two variables of the positional deviation amount w and the surface distance g will be described below.

FIG. 1 is a schematic view of the essential parts of Embodiment 1 of the present invention, and FIG. 2 is a schematic view of the essential parts when the optical paths of the respective luminous fluxes of FIG. 1 are schematically developed. In FIG. 1 and FIG. 2, L1 is a light beam from a light projecting means such as a semiconductor laser, an SLD, or an X-ray source, which is not shown, and is angled to a physical optical element Z1 or Z3 described later on the surface of the first object 1 such as a mask. It is incident at θ. Reference numeral 2 denotes a second object such as a wafer, which is arranged to face the first object 1 with a gap g. w indicates a relative shift amount between the first object 1 and the second object 2. Z1 and Z3 are transmissive first and third physical optical elements provided on the surface of the first object 1, and the light beam L1 is incident on the physical optical elements Z1 and Z3. Z2
Z4 is a reflection type (shown as a transmission type in FIG. 2) second and fourth physical optical elements provided on the surface of the second object 2, and these physical optical elements (hereinafter also referred to as “marks”). Z1
Z4 are composed of, for example, a diffraction grating and a zone plate.

FIG. 3 shows a pattern example of the physical optical element on the surfaces of the first object 1 and the second object 2 according to this embodiment.

The physical optical elements Z1 to Z4 have a lens function and their focal lengths are f1 to f4, respectively.

L2 to L9 are diffracted light of a predetermined order from the physical optical element, and 3 is a detecting means, for example, a sensor such as a line sensor or an area sensor, which is arranged at a position separated from the first object 1 by a distance L. . a1 and a2 are optical axes of the physical optical elements Z1 and Z3, respectively, of which optical axis a1 and optical axis a
It is separated by a distance D from No. 2.

Points C1 to C4 are diffracted lights L3 and L, respectively.
5, L7, and L9 are the barycentric positions of the light flux on the sensor 3 surface.
Of these points, points C1 and C2 are distances Y1 and Y from the optical axis a1.
The points C3 and C4 are two points away from each other, and the points C3 and C4 indicate positions that are distances Y3 and Y4 from the optical axis a2.

Here, in the light beam cross section, the light beam center of gravity is a vector of 0 when the position vector from each point in the cross section is multiplied by the light quantity at that point and integrated over the entire cross section. Is shown.

Reference numeral 4 is a signal processing circuit as a calculation means, and the light fluxes L3, L5, L are obtained from the information from the sensor 3.
7 and L9 are calculated.

At this time, in the present embodiment, the relationship between the deviation amount w when the distance between the first object and the second object is g and the incident position information Y of the diffracted light of the predetermined order on the surface of the sensor 3 is experimentally determined. In various cases, the general formula is created. Then, the general formula at this time is recorded in, for example, a recording means provided in a part of the arithmetic means 4 or a recording means (not shown) provided outside. Then, the distances Y1 to Y4, D, which are position information, are recorded in the recording means.

Using the general formula, the first object 1 and the second object 2
The positional shift amount w and the gap g are calculated. Reference numeral 5 denotes a control circuit, which controls the positional deviation amount w and the interval g between the first object 1 and the second object 2 in accordance with the information on the positional deviation amount w and the interval g from the signal processing circuit 4.

A stage controller 6 drives a stage (not shown) on which the second object 2 is mounted according to a command from the control circuit 5.

In this embodiment, the light beam L1 from the light source is incident on each of the physical optical elements Z1 and Z3 on the surface of the first object 1. Of these, the first-order diffracted light L2 generated by the physical optical element Z1 of the light flux L1 incident on the physical optical element Z1 is incident on the physical optical element Z2. Then, the first-order diffracted light L3 having a different diffracting direction is generated according to the positional shift amount w. The diffracted light L3 passes through the physical optical element Z1 as it is as the 0th-order diffracted light. The diffracted light L3 is a distance Y from the optical axis a1 on the surface of the sensor 3.
An image is formed at a position separated by one. Since the distance between the sensor 3 and the first object 1 is a constant value L, the value of the distance Y1 is an amount that depends on the interval g and the positional deviation amount w.

On the other hand, the light beam L1 that has passed through the physical optical element Z1 as the 0th-order diffracted light without being diffracted enters the physical optical element Z2. Then, the first-order diffracted light L4 that has been subjected to the first-order diffracting action by the physical optical element Z2 re-enters the physical optical element Z1. Then, the first-order diffracted light L5 having a different diffracting direction is generated according to the amount of positional deviation w. The first-order diffracted light L5 is detected by the sensor 3
An image is formed on the surface at a distance Y2 from the optical axis a1.

From the light beam L1 incident on the physical optical element Z3, diffracted light beams L6 to L9 similar to the light beam L1 incident on the physical optical element Z1 are generated. Of these, diffracted light beams L7 and L9 are light beams on the surface of the sensor 3, respectively. Images are formed at positions apart from the axis a2 by distances Y3 and Y4. Reference numeral 4 denotes a signal processing circuit as an arithmetic means, which first detects the light flux L from the information read from the sensor 3.
3, L5, L7, L9 light beam centroid positions C1, C2, C
3, after obtaining C4, the distance D14 between the points C1 and C4,
The distance D23 between the points C2 and C3 is calculated. Interval D14
And the value of the interval D23 using the relationship of each equation described later
The positional shift amount w and the gap g between the object 1 and the second object 2 are obtained.

The control circuit 5 drives the stage controller 6 according to the information on the positional deviation amount w and the gap g from the signal processing circuit 4 to move the second object 2 to a predetermined position.

In this embodiment, the diffracted light is not limited to the first-order diffracted light, and the same effect can be obtained by using the second-order or higher-order diffracted light.

In the present embodiment, since the light source, the sensor and the like can be assembled in one place, the optical probe can be miniaturized, and the movement of the optical probe at the time of exposure is unnecessary, so that the throughput is further improved. It has features such as

Next, how to obtain the positional deviation amount w and the gap g between the first object 1 and the second object 2 in this embodiment will be described with reference to FIG.

In the lens system for generating the diffracted light L3 in FIG. 2, the light beam L1 passes through the physical optical elements Z1 and Z2 having a lens function and is incident on the point C1. At this time, the diffracted light L
The distance Y1 to the light beam center of gravity C1 of 3 is an amount determined by the shift amount w between the first object 1 and the second object 2 and the gap g, and generally Y1 = F1 (w, g). ) Is represented.

Similarly, in the other three lens systems, the distances Y2, Y3 and Y4 are determined by the shift amount w and the gap g. Y2 = F2 (w, g) (2) Y3 = F3 (w, g) ··· (3) Y4 = F4 (w, g) ··· (4)

When the distances Y1 to Y4 are expressed as described above, if the distance D13 between the points C1 and C3 and the distance D24 between the points C2 and C4 are used, the shift amount w and the distance g are as follows.
It is possible to represent the quantities Y and Z (hereinafter also referred to as “objective variables”) depending on

Y = y1 + y3 = D13−D = F1 + F3 = F5 (w, g) Z = y2 + y4 = D24−D = F2 + F4 = F6 (w, g) ′ That is, the objective variables Y and Z are expressed as follows. You can

Y = a ₀ + a ₁ w + a ₂ g (5) Z = b ₀ + b ₁ w + b ₂ g (6) Here, the coefficient a of the equations (5) and (6) ₀ , a ₁ , a ₂ , b
_{If 0} , b ₁ and b ₂ are determined in advance, by measuring the target variables Y and Z when the value of the given deviation amount w and the interval g are measured,
The values of the shift amount w and the interval g can be obtained.

Next, how to determine the above-mentioned coefficients will be described. First, the values of the objective variables Y and Z for various combinations of the deviation amount w and the value of the interval g within the measurement range are measured, and three or more sets of data as shown in Table 1 are prepared. Table 1 and (5),
The following equation is obtained from the equation (6).

[0043]

[Equation 1] The following multiple regression equations are respectively obtained from the equations (7) and (8).

Y = A ₀ + A ₁ w + A ₂ g (9) Z = B ₀ + B ₁ w + B ₂ g (10) From the above, the respective coefficients a ₀ , a ₁ , a ₂ , b ₀ , b ₁ , b ₂ are obtained. Then, the shift amount w and the interval g are obtained using the values of the objective variables Y and Z.

FIG. 4 shows diffracted light beams L3 and L in this embodiment.
5, L7, L9 luminous flux centroids C1, C2, C3, C4,
It is an explanatory view showing how it changes on the sensor 3 surface according to shift amount w. Diffracted light beams L3, L5, L7, L
Since 9 and the like have a certain width on the sensor surface, it becomes difficult to accurately determine points C1 to C4 if there are portions that overlap each other.

Therefore, in this embodiment, for example, the shift amount w = ±
When it is desired to measure within 3 μm, the characteristics of the range in which the respective light fluxes are separated (for example, between point wo-3 and point wo + 3 in FIG. 4) are obtained in advance by simulation or the like and used.

That is, in the present embodiment, the barycentric positions of the first and second diffracted light beams generated on the predetermined surface through the first and second physical optical elements and the third and fourth physical positions. 2nd, 3rd and 4th generated on a predetermined surface via two physical optical elements
The barycentric positions of the two diffracted light beams are detected in a state of being separated by at least the width of the diffracted light beams.

In this embodiment, when the positional displacement amount w between the first object and the second object is 0, the optical axis a1 of the physical optical element (for example, Z1) on the first object and the physical optics on the second object. By shifting the optical axis a2 of the element (for example, Z2) by the distance wo, the positional displacement amount w between the first object and the second object is 0.
At this time, the points C1 and C2, and the points C3 and C4 can be separated from each other.

The first to fourth physical optical elements Z1 to Z1 shown in FIG.
The pattern arrangement of Z4 shows this state, and when the positional displacement amount w of the first object and the second object is 0, the optical axes of the first and second physical optical elements Z1 and Z2 are the third and fourth. The optical axes of the physical optical elements Z3 and Z4 are set so as to be displaced by the distance wo.

Therefore, when this pattern is used, the first
When the object and the second object are displaced by the distance wx (9)
The value of the shift amount w in the equation (12) may be replaced with w = wo + wx for calculation.

In this embodiment, instead of providing two physical optical elements on each of the first and second object planes, four physical optical elements are provided on one of the object planes and the above-mentioned diffracted light beam L3 is generated. L
The same effect can be obtained by obtaining four diffracted lights corresponding to 5, L7, and L9.

However, the method of providing two physical optical elements as in this embodiment requires a smaller area than the method of providing four physical optical elements, and the amount of diffracted light is 2 when compared in the same area. It has the advantage of being doubled.

Next, how to prepare the data in Table 1 will be described. Since the value of the deviation amount w is generally required to have an accuracy of 0.01 μm or less in an exposure apparatus for manufacturing a semiconductor element, a method of obtaining the value of the deviation amount w will be described with reference to FIGS. 5 and 6.

In FIG. 5, marks Z5 and Z7 are marks corresponding to the marks Z1 and Z3 in FIG. 3, and a mark AF is a mark for measuring the gap g between the mask and the wafer.
5 and Z7 are mounted on the mask.

In FIG. 6, marks Z6 and Z8 are marks corresponding to the marks Z2 and Z4 in FIG. 3, and w ₁ , ..., W ₅ are when the amount of displacement between the mask and the wafer is zero, that is, the mask. It shows the amount of positional deviation between the marks Z5 and Z7 on the mask and the marks Z6 and Z8 on the wafer when the amount of positional deviation between the upper mark M1 and the mark M2 on the wafer is zero.

In the case of the above configuration, the positional deviation amount w ₁ ,
..., dependent variable Y while changing the gap g as shown in Table 2 when the value of w ₅ are accurately known, if Hakare the Z value n data are obtained.

Next, an accurate method of measuring the values of the positional deviation amounts w ₁ , ..., W ₅ will be described.

A mark Z is formed on the wafer as shown in FIG.
6 and Z8 are printed with the positional deviation amounts w ₁ , ..., W ₅ distant from each other. Mark M1 on the mask and wafer
And mark M2 as the alignment mark. The target variable Y value at this time is Y _M.

The mark M1 and the mark M2 are aligned with each other.
When done, the other marks Z5, Z7 and marks Z6, Z8
The positions of and are also in a substantially matched state. Misalignment at this time
Quantity w ₁ ・ ・ ・ ・ ・ ・, W_Five Objective variable Y of distant mark group
The value is Y₁ ・ ・ ・ ・ ・ ・, Y_Five And

Looking at the relationship between the value of the objective variable Y _{M and} the value of Y ₁ , the value of Y ₁ is the sum (or difference) of the Y value and the value of Y _M due to the shift amount w ₁ . . Therefore, the position shift amount w ₁
If the Y value by Yw ₁ is Yw ₁ , then | Yw ₁ | = | Y ₁ −Y _M |

If the magnification of the lens system of the mark group having the Y value of Y ₁ is M times, the shift amount w ₁
The w ₁ = | can be obtained as / _M | Y ₁ -Y M.

The Y value can be accurately obtained when the interval g is a predetermined value.
Using the method disclosed in Japanese Patent Publication No. 167413,
The interval g is set to an accurate value.

Next, an embodiment in the case where there are three or more variables in the present invention will be described.

As can be seen from the first embodiment described above, when there are k unknown variables (explanatory variables), k multiple regression equations are required.

Therefore, referring to Table 1, Table 3 is used in this embodiment.
It turns out that an objective variable such as is necessary. When the target variables are aligned as shown in Table 3, the following equation is obtained.

[0066]

[Equation 2] Since k expressions are prepared for k unknowns, X ₁ , X
_When the values of _{2 to} X _k are specifically obtained from the position of the light flux, the values of unknowns X ₁ and X _{2 to} X _k are obtained.

Needless to say, the solution can be obtained from the equation (14) even when the number of unknowns is k or less.

Next, a method of obtaining k objective variables will be described.

Specifically, the above equation (1) is used to describe the positional displacement amount w,
For example, paraxial geometrical optics can be represented by the interval g as follows. From Fig. 2 Y1: w = L + 2g-f1: f1-g

[0070]

[Equation 3] Becomes

As is well known, the focal length of the zone plate changes when the frequency of the light beam projected on the zone plate is changed. Therefore, (15), (16), (17),
As can be seen from the equation (18), when the frequency changes, the sensor 3
The position of the upper light flux changes.

That is, in FIG. 1, for example, points C1 and C3, point C2
It is possible to prepare four objective variables from C4 and C4, points C1 and C4, and points C2 and C3, but by further changing the frequency, four more objective variables are prepared. Therefore, in general, if the frequency is variable in 10 ways, 4 × 10 objective variables can be prepared. In addition, for example, (x
₁₁₎ If you want to add the square terms like ² (x ₁₁₎ ² =
The multiple regression equation can be treated as a linear regression equation by replacing it with x _m .

However, since the number of variables increases by one, the number of required regression equations increases by one. The same applies when terms of the third power or more and terms of trigonometric functions are included.

Variable frequency lasers that can be used as the light source in this embodiment include Zeeman lasers, multi-wavelength LDs, wavelength tunable lasers using dye lasers, and parametric oscillation lasers using non-linear crystal BBO.

FIG. 7 is an explanatory diagram of a frequency selection method when a Zeeman laser is used as a light source. In FIG. 7, PBS1 and PBS2 are polarization beam splitters, Sw1 and Sw2 are AO optical switches, M1, M2, and M.
Each of 3 is a mirror.

With the above-mentioned structure, the lights of the two frequencies f1 and f2 in the Zeeman laser are separated into two by the PBS1.
Light of either one of the frequencies is selected by the AO optical switches Sw1 and Sw2.

FIG. 8 is an explanatory diagram of a method of increasing the objective variable by hardware. In FIG. 8, M4 is a half mirror, M5
Is a mirror and 3 is a sensor.

With the above-mentioned structure, the diffracted lights L3 and L5 from the mark Z1 are respectively reflected by the half mirror M4 as the light flux L.
3'and L3 "and luminous fluxes L5 'and L5" are split and reach the sensor 3. By similarly separating the diffracted light from the mark Z3, the objective variable is doubled. If the number of half mirrors is increased, the objective variable can be increased.

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

FIG. 9 shows a flow of manufacturing semiconductor devices (semiconductor chips such as IC and LSI, or liquid crystal panels, CCDs, etc.). In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (mask manufacturing), a mask having the designed circuit pattern is manufactured.

On the other hand, in step 3 (wafer manufacturing), 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 a lithography technique using the mask and the wafer prepared above.

The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer manufactured in step 4, an assembly process (dicing, bonding), a packaging process (chip encapsulation). Etc. are included.

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

FIG. 10 shows the detailed flow of the wafer process. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), 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 in the wafer. Step 15
In (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed and exposed on the wafer by the exposure apparatus described above.

In step 17 (development), the exposed wafer is developed. In step 18 (etching), parts other than the developed resist image are removed. In step 19 (resist stripping), the resist that is no longer needed after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the manufacturing method of this embodiment, it is possible to manufacture a highly integrated semiconductor device which has been difficult to manufacture in the past.

[0088]

[Table 1]

[0089]

According to the present invention, as described above, the distance between the first object and the second object is the distance g, the positional deviation amount w, the light projecting means and the first object.
The positional information Y from the detecting means when the positional displacement amount and the like with respect to the object are all known and they are opposed to each other is obtained in advance for various cases, the multiple regression equation is obtained from this and recorded in the recording means. By using the position information from the detecting means and the general formula recorded in the recording means at the time of actually detecting both positions, the semiconductor laser caused by the aberration of the detection system, the manufacturing error, and the secular change. It is possible to achieve a position detection device that eliminates the influence of error factors such as changes in the oscillation wavelength of the above, and can perform relative position detection of both with high accuracy.

Further, according to the present invention, the positional deviation amount w between the first object and the second object, the distance g between the first object and the second object, the positional deviation amount between the light projecting means and the first object, and the like are calculated. By obtaining the position, it is possible to achieve a position detecting device with high throughput by performing a matrix operation that can perform highly accurate alignment without erroneously recognizing the matching state and that can be easily operated.

For example, in the case of performing alignment based only on the relationship between the positional information C1 and C3 and the shift amount w in the position detecting device of the present invention, the above-mentioned constants are g = 30 μm and f1 = 150.
μm, L = 18627 μm, y1 = 1544.45 μm
At this time, if the gap g has an error of 0.06 μm, the deviation amount w
Has an error of 0.005 μm. Therefore 0.01μ
When attempting to perform alignment with an accuracy of m, it is necessary to make the error of the gap g about 0.06 μm or less. Therefore, it is necessary to set the interval g with an accuracy of 0.06 μm or less in advance by some method.

On the other hand, according to the present invention, if the gap g is set with a certain degree of accuracy in the prealignment, the shift amount w can be accurately obtained regardless of the value of the gap g.

Further, in the method of determining the center of gravity of two diffracted light beams by measuring the diffracted light beams whose positions of the centers of gravity are positions C1 and C2, the center of gravity moves when the light quantity changes due to fluctuations in diffraction efficiency, etc. However, in the present invention, since the diffracted light beams are measured in a state where they are sufficiently separated from each other, such a detection error can be prevented.

Further, in the present invention, the physical optical element is commonly used for detecting the positional deviation amount w, the gap g, the positional deviation amount between the light projecting means and the first object, and the like, whereby the luminous flux and the physical optical element are detected. The number is reduced, the detection system is simplified, and the entire device is downsized.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of a first embodiment of the present invention.

FIG. 2 is a schematic view of main parts when the optical paths of the respective light fluxes in FIG. 1 are schematically developed.

FIG. 3 is an explanatory view of a physical optical element provided on a surface of a first object 1 and a surface of a second object 2.

FIG. 4 is a shift amount w and light beam centroid positions C1, C2, C
Explanatory drawing which shows the positional relationship on the sensor surface of 3 and C4.

FIG. 5 is an explanatory diagram of how to set the deviation amount w.

FIG. 6 is an explanatory diagram of how to set a deviation amount w.

FIG. 7 is an explanatory diagram of a method of polarizing the frequency of light from a light source.

FIG. 8 is an explanatory diagram of a method of increasing the number of objective variables of the multiple regression equation.

FIG. 9 is a flowchart of manufacturing the semiconductor device of the present invention.

FIG. 10 is a flowchart of manufacturing a semiconductor device of the present invention.

FIG. 11 is a schematic view of a main part of a conventional position detection device.

FIG. 12 is a schematic view of a main part of a conventional position detecting device.

[Explanation of symbols]

1 first object (mask) 2 second object (wafer) 3 detection means 4 signal processing circuit 5 a control circuit 6 stage controller w shift amount g intervals L1~L9 light beam Z1~Z4 physical optic element x ₁ ~x _k explanatory variable X _{1 to} X _k objective variable

Claims (5)

[Claims] 1. A physical optical element is provided on each of a first object surface and a second object surface, and a light beam is incident on these physical optical elements from a light projecting means, and a predetermined order of the light beam is generated on the predetermined surface. When the relative position between the first object and the second object is detected by detecting the position information of the diffracted light beam by the detecting means, the weight based on the relative positional relationship between the first object and the second object is detected. At least the same number of positions of diffracted light as the number of regression equations are generated, and k × n (where k and n are positive integers) of the first information are generated.
The k multiple regression equations are calculated from the positional deviation amount and the distance between the object and the second object and the position information of the k × n diffracted light, and the k multiple regression equations and the positions of the k diffracted light are obtained. A position detecting device characterized in that a maximum of k positional deviation amounts and distance values between the first object and the second object are obtained by a calculation means from information, and a signal from the calculation means is used. 2. The position detecting device according to claim 1, further comprising frequency changing means for changing the frequency of the light beam from said light projecting means. 3. The position detecting device according to claim 1, wherein a part of the diffracted light from the physical optical element is divided and guided on a predetermined surface. 4. A regression equation is obtained by using a positional displacement amount of a physical optical element on the second object surface as a positional displacement amount between the first object and the second object. Or the position detection device of 3. 5. The pattern on the mask surface is transferred onto the wafer surface after detecting the relative position between the mask and the wafer,
At the time of manufacturing a semiconductor element through the developing process of the wafer, at least the same number of position information pieces of diffracted light as the number of multiple regression equations based on the relative positional relationship between the first object and the second object are obtained. Then, k weights are generated from k × n (where k and n are positive integers) positional deviation amounts and intervals between the first and second objects and k × n diffracted light position information. A regression equation is obtained, and a maximum k is obtained from the k multiple regression equations and the position information of the k diffracted lights.
A method of manufacturing a semiconductor element, wherein the number of positional deviations and the values of the intervals between the first object and the second object are calculated by a calculation means, and a signal from the calculation means is used.