JP3439468B2 - Method for manufacturing phase shift mask - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a phase shift mask.
In particular, with regard to the manufacturing technology of
Effective technology applied to exposure technology to transfer integrated circuit patterns
It is about art. [0002] 2. Description of the Related Art In recent years, in semiconductor integrated circuits,
Of the elements and wiring that make up
The gap is being narrowed. [0003] However, the miniaturization of such elements and wiring,
In addition, as the spacing between elements and wiring becomes narrower, at least
Irradiation of partially coherent light allows semiconductor wafers
Transfer the integrated circuit pattern onto c (hereinafter referred to as wafer)
Degradation of mask transfer accuracy of masks is becoming a problem
is there. [0004] This will be described with reference to FIGS.
The result is as follows. That is, the mask 50 shown in FIG.
The predetermined integrated circuit pattern on
When transferring onto an eha (not shown), one
The phase of the light transmitted through each of the pair of transmission regions P1 and P2 is
Since they are in phase as shown in FIG.
As shown in FIG. 18 (c), the light transmission
Strengthen each other in the light shielding area N sandwiched between the areas P1 and P2.
Would. For this reason, as shown in FIG.
Modulation of light intensity distribution on EHA (modula
of the mask pattern transfer accuracy
It will drop significantly. As means for improving such a problem, for example,
For example, the phase difference between light transmitted through each of a pair of transmission areas
Have been proposed. For the phase shift mask, for example,
It is described in JP-A-62-59296, and
Is a mask having a light shielding area and a transmission area.
A transparent material is provided on at least one of the pair of transmission regions sandwiching the light region.
Between the light transmitted through each transmission area during exposure.
Causes a phase difference, and these lights are originally blocked on the wafer
So that they do not interfere and reinforce each other
The described mask structure is described. The effect of transmitted light in such a mask is
19 (a) to 19 (d) are as follows.
is there. That is, the mask 51 shown in FIG.
The predetermined integrated circuit pattern on
When transferring onto an eha (not shown), one
Of the pair of transmission areas P1 and P2,
Of the light transmitted through the transmitted transmission region P2 and the normal transmission region.
FIG. 19 (b) shows the phase difference between the light transmitted through the region P1 and the phase.
As shown in (c), a phase difference of 180 degrees occurs. Therefore, the pair of transmission areas P1, P2 is defined as
The transmitted light is blocked by these transmission areas P1 and P2.
Since the light beams interfere with each other in the optical region N and cancel each other, FIG.
As shown in (d), the mode of the light intensity distribution on the wafer
Improves the duration and transfers the pattern of the mask 51
Accuracy is improved. [0012] SUMMARY OF THE INVENTION As described above, the semiconductor
In integrated circuits, the elements and wiring that make up the circuit
And the spacing between elements and wiring have been increasingly narrowed.
Therefore, how high the pattern transfer accuracy is
The issue is how to manufacture a phase shift mask. An object of the present invention is to provide a phase shifter pattern and a shield.
A method of manufacturing a mask that can perform good alignment with an optical film
To provide. The above and other objects and novel objects of the present invention
Features are apparent from the description of this specification and the accompanying drawings.
Will be. [0015] SUMMARY OF THE INVENTION The present invention is disclosed in the present application.
A brief description of typical inventions will be given below.
It is as follows. That is, the present invention provides:Prepare the mask substrate
Forming an integrated circuit pattern and
And phase shifter patterns.
Forming a light-shielding film having an alignment mark,
Based on the alignment mark provided on the light shielding film
Irradiating the mask substrate with an ion beam.
The phase shifter pattern
FormProcessWhenIt has. [0017] Embodiments of the present invention will be described below with reference to the drawings.
Will be described in detail based on
In all the drawings for illustration, those having the same function
And the repeated explanation is omitted). (Embodiment 1) FIG. 1 shows an embodiment of the present invention.
2 (a) to 2 (c) are cross-sectional views of a main part of a mask which is an embodiment.
FIG. 3 is a cross-sectional view of a main part of a mask showing a manufacturing process of this mask.
FIG. 2A is a cross-sectional view showing an exposure state of the mask shown in FIG.
3 (b) to 3 (d) show light transmitted through the transmission region of the mask.
FIG. 4 is an explanatory diagram showing the amplitude and intensity of a sine wave. The mask 1a of the first embodiment shown in FIG.
For example, in a predetermined manufacturing process of a semiconductor device,
Transfer a predetermined integrated circuit pattern onto a wafer not shown
5 times the size of an integrated circuit pattern
Reticle on which the original image was formed (hereinafter referred to as a 5-fold reticle)
U). A transparent mask substrate constituting the mask 1a
(Hereinafter, simply referred to as a substrate) 2 has, for example, a refractive index of 1.47.
Of synthetic quartz glass, on its main surface, for example,
Metal with a thickness of 500-3000mm (= 50-300nm)
The layer 3 is patterned in a predetermined shape. The metal layer 3 is made of, for example, a Cr layer or
Is composed of a Cr oxide layer laminated on a Cr layer,
At the time of exposure, it becomes the light-shielded area A. Also, the metal layer 3 is removed.
The part that has been removed becomes a transmission area B during exposure. So
Then, the light-shielding area A and the transmission area B are used to integrate the light.
The original of the road pattern is constructed. In the first embodiment, the above-described metal
Pattern so that it is slightly wider than the pattern width of layer 3.
The formed transparent film 4a is disposed. That is,
The mask 1a includes a transparent region from the contour of each metal layer 3.
The transparent film 4a which has partially protruded from B is pattern-formed.
You. In other words, one transmission region B is formed on the transparent film 4a.
The coated part and the part where the transparent film 4a is not formed
It consists of. The transparent film 4a is made of indium oxide (In)
O_X), For example, the pattern width of the transmission region B
Is 2 μm, the width of the protruding transparent film 4a is 0.5
It is about μm. Then, temporarily, the transparent film 4a
The thickness from the main surface of the substrate 2 is X1, the refractive index of the substrate 2 is n,
Assuming that the wavelength of the light irradiated upon exposure is λ, the transparent film 4
a indicates that the thickness X1 of X1 = [lambda] / [2 (n-1)]
It is formed to satisfy the relationship. This is the exposure
Light irradiated on the mask 1a and transmitted through one transmission region B
Of the light transmitted through the transparent film 4a and the normal transmission
A phase difference of 180 degrees between the phase of light transmitted through the region B and
It is to cause it. For example, it is irradiated at the time of exposure
The wavelength λ of the light is 0.365 μm (i-line),
Assuming that the refractive index is 1.5, the main surface of the substrate 2 of the transparent film 4a
The thickness X1 may be set to about 0.37 μm. Although not shown, the mask 1a includes:
For example, when the transparent film 4a is formed,
An alignment mark for alignment is formed. Next, manufacture of the mask 1a of the first embodiment
The method will be described with reference to FIGS. First, as shown in FIG.
On the main surface of the purified transparent substrate 2, for example, a thickness of 500 to
Sputter the metal layer 3 made of 3000% Cr etc.
And then the upper surface of the metal layer 3
Then, for example, a photoresist 5a having a thickness of 0.4 to 0.8 μm is formed.
Apply. Then, the photoresist 5a is pre-baked.
After that, it is encoded in advance on a magnetic tape (not shown).
Position of integrated circuit pattern of semiconductor device recorded and recorded
Based on pattern data that contains markers, shapes, etc.,
Predetermined photoresist 5a by electron beam exposure
The portion is irradiated with an electron beam E. Thereafter, as shown in FIG.
The exposed portion of the resist 5a is removed with a predetermined developing solution,
The exposed metal layer 3 is etched by dry etching or the like.
To form a pattern in a predetermined shape. Then, the photoresist is removed by a resist stripper.
After removing the strike 5a and cleaning and inspecting the substrate 2, FIG.
As shown in (c), the main surface of the substrate 2
Of indium oxide (InOx) having a thickness of about 0.37 μm
A transparent film 4a made of a material such as
It is formed by a sputtering method or the like. Next, on the upper surface of the transparent film 4a, for example,
A 0.4-0.8 μm photoresist 5b is applied,
Further, on the upper surface, for example, an aluminum
Antistatic layer 6 made of aluminum (Al) by sputtering
It is formed by such as. Thereafter, the pattern of the above-described integrated circuit pattern is
Of the light-shielding area A or the transmission area B
Transparent film 4a obtained by enlarging or reducing the width of the pattern
Electron beam exposure method based on the
For example, the photoresist 5 in a portion where the transparent film 4a is left
b is irradiated with an electron beam E and exposed. In the first embodiment, the above-described transparent
The pattern data of the film 4a is, for example, the pattern of the light shielding area A.
It is created automatically by increasing the line width.
It has become. That is, the pattern data of the transparent film 4a
When creating pattern data for integrated circuit patterns
In the same way, instead of creating specially,
Created based on the pattern data in the application. After exposing the photoresist 5b,
Image, etching of predetermined part of transparent film 4a, photoresist
After the steps of removing 5b, cleaning and inspection, etc.
The mask 1a shown in FIG. 1 is manufactured. Using the mask 1a manufactured in this manner,
And a mask 1 is placed on the photoresist-coated wafer.
To transfer the integrated circuit pattern on a, for example,
To do. That is, a reduction projection exposure apparatus (not shown)
By disposing the mask 1a and the wafer, the collection on the mask 1a is performed.
The original of the integrated circuit pattern is optically reduced to 1/5 and
C and project the wafer sequentially in steps.
By repeatedly projecting and exposing each time
The integrated circuit pattern is transferred to the entire surface of the wafer. Next, the operation of the first embodiment will be described with reference to FIG.
This will be described with reference to (d). The mask according to the first embodiment shown in FIG.
1a, a predetermined integrated circuit pattern on the mask 1a
Transfer original image on wafer by reduction exposure method etc.
At this time, in each transmission region B of the mask 1a, the transparent film 4
a between the light transmitted through a and the light transmitted through the normal transmission region B.
A phase difference of 180 degrees occurs between them (FIG. 3B,
(C)). The transparent film 4a is formed at the end of each metal layer 3.
Light transmitted through one transmission area B
Of the light transmitted through the transparent film 4a and the normal transmission area B
The transmitted light is transmitted to the light shielding areas A and A adjacent to the transmission area B.
Weaken each other at the border. Therefore, the light intensity distribution on the wafer
The modulation is greatly improved (Fig. 3
(D)). In particular, each light-shielded area projected on the wafer
The blur at the end of A is greatly reduced, and the pattern transfer accuracy is improved.
It can be greatly improved. The light intensity is
Since it is the square of the amplitude, the negative side of the light amplitude on the wafer
Is inverted to the positive side as shown in FIG.
You. By the way, the conventional technique uses a pair of transmissive regions.
Technology that creates a phase difference between light transmitted through
This is a technology that produces one effect in two transmission areas.
Was. The problem to be solved by the invention
As described in the section, the pattern is
When turns are complicated and two-dimensionally arranged
If the pattern transfer accuracy is partially reduced,
As a result, the arrangement of the transparent material was restricted. That is, all patterns of the pattern on the mask
The placement of transparent material that improves turn transfer accuracy is not
It was always difficult. Therefore, the pattern data of the transparent material is
If you can not create it automatically and create it
Is used to prevent the pattern transfer accuracy from partially lowering.
Special patterns for transparent materials are set up, taking into account the layout.
Calculate, draw, and computer-process this pattern.
And must be created by. On the other hand, the mask 1 of the first embodiment
In the case of a, the light is transmitted through one transmission area.
A technology that creates a phase difference and improves pattern transfer accuracy
Therefore, the pattern formed on the mask 1a is complicated.
However, the transparent film 4a can be arranged correspondingly. For this reason, the arrangement of the transparent film 4a is easy.
The pattern data of the transparent film 4a is easily
Pattern of the light-shielding area A or the transmission area B constituting the pattern
Can be created automatically based on the
You. As described above, according to the present embodiment, the following effects can be obtained.
Fruit can be obtained. (1) In each transmission area B of the mask 1a, the transparent film 4
a between the light transmitted through a and the light transmitted through the normal transmission region B.
A 180-degree phase difference is generated between the light-shielded areas A
Are weakened at the boundary between
The modulation of the light intensity distribution on c has been greatly improved
You. In particular, the pattern of the light shielding area A projected on the wafer
The blur at the edges of the image is greatly reduced, and the pattern transfer accuracy is improved.
It can be greatly improved. (2) The pattern formed on the mask by (1) above
However, even if it is a fine and complicated integrated circuit pattern,
The pattern transfer accuracy does not decrease
The transfer accuracy of all the components can be improved. (3). The transparent film 4a for shifting the phase has one transmission region.
This technology considers only the phase difference of light transmitted through B.
Therefore, even if it is a complicated integrated circuit pattern,
It will be easier. (4) According to the above (3), the pattern data of the transparent film 4a is
The light shielding area A or the transmission area constituting the integrated circuit pattern
Automatically create based on pattern data in area B
Can be. (5) According to the above (3) and (4), the pattern data of the transparent film 4a is obtained.
Phase shift because you can create
The manufacturing time of the mask 1a on which the transparent film 4a is
It can be greatly reduced. (Embodiment 2) FIG. 4 shows another embodiment of the present invention.
5 (a) and 5 (b).
Is a cross-sectional view of a main part of the mask, showing a manufacturing process of the mask.
6 is a focused ion beam used in manufacturing this mask.
FIG. 7 (a) is a view showing the structure of a mask device shown in FIG.
FIGS. 7B to 7D are cross-sectional views showing optical states, and FIGS.
Explanatory diagram showing the amplitude and intensity of light transmitted through the transmission region of FIG.
It is. The mask 1b of the second embodiment shown in FIG.
In the exposure, the light transmitted through the transmission area B during the exposure has a phase difference
As means for causing the transparent film 4a of the first embodiment.
Instead, during the exposure, the phase shift
A groove 7a is formed. The phase shift groove 7a is used as a light shielding area during exposure.
A along the edge of the metal layer 3, that is, the metal layer 3
Are formed along the outline of the. Of the phase shift groove 7a
The width is set, for example, such that the pattern width of the transmission region B is 2 μm.
And about 0.5 μm. And, suppose that the depth of the phase shift groove 7a is
d, the refractive index of the substrate 2 is n, and the wave of light emitted during exposure
If the length is λ, the depth d of the phase shift groove 7a is
d = λ / [2 (n−1)].
Have been. This is the light irradiated on the mask 1b during the exposure.
In each of the transmission regions B, the phase shift groove 7a is
The phase of the transmitted light and the light transmitted through the normal transmission region B
Phase difference of 180 degrees with the
You. For example, the wavelength λ of the light irradiated at the time of exposure is set to 0.
If it is 365 μm (i-line), the depth of the phase shift groove 7a
d may be about 0.39 μm. Although not shown, the mask 1b has
When forming the phase shift groove 7a, alignment with the metal layer 3 is performed.
Alignment marks for
You. Next, it is used for manufacturing the mask 1b.
The focused ion beam device 8 will be described with reference to FIG. The ion source 9 provided at the upper part of the apparatus main body
Although not shown, for example, gallium (Ga)
Etc. are stored. Of ion source 9
A lead electrode 10 is provided below, and below it.
The first lens electrode 1 composed of an electrostatic lens
1a and the first aperture electrode 12a are provided.
You. A second lens electrode is provided below the aperture electrode 12a.
11b, the second aperture electrode 12b, and O
Blanking electrode 13 for controlling N and OFF,
A 3-aperture electrode 12c and a deflection electrode 14 are provided.
ing. With such a configuration of each electrode, ions
The ion beam emitted from the source 9
Controlled by the electrode 13 and the deflection electrode 14,
Irradiate the mask 1b before pattern formation held at
It is supposed to be. It should be noted that the ion beam is scanned during the scanning.
For example, for each pixel of 0.02 × 0.02 μm,
Set the irradiation time and set the number of scans in advance
Thus, the metal layer 3 or the substrate 2 can be etched. [0057] The cage 15 can be moved in the X and Y directions.
The sample table 16 is set on the side
Laser interferometry via the laser mirror 17
The position of the sample stage is recognized by the
The alignment is performed by the
I have. It should be noted that a secondary ion
・ The secondary electron detector 20 is installed, and from the workpiece
Detection of secondary ions and secondary electrons
Has become. In addition, the secondary ion and secondary electron detection described above
An electron shower radiator 21 is provided above the vessel 20.
To prevent the workpiece from being charged.
You. The inside of the processing system described above is
The vacuum pump 22 shown below the sample stage 16
And a vacuum state is maintained. Each of the above-described processing systems is provided outside the main body of the apparatus.
The operation is controlled by the control units 23 to 27 provided in the unit.
Each of the control units 23 to 27 further controls
Control computer 3 via interface units 28 to 32
3 is controlled. Control computer
The data 33 includes a terminal 34 and magnetic data for recording data.
A disk device 35 and an MT deck 36 are provided. Next, a method of manufacturing the mask 1b will be described with reference to FIG.
This will be described with reference to (a) and (b) and FIG. First, as shown in FIG.
On the main surface of the cleaned substrate 2, for example,
After forming the metal layer 3 by a sputtering method or the like,
The disk 1b is held in the holder 15 of the focused ion beam device 8.
Let it. Next, an ion beam is emitted from the ion source 9.
Out, and this ion beam is, for example,
If the beam is focused to a beam diameter of 0.5 μm, the aperture will be about 1.5 μA.
An on-beam current is obtained, and the magnetic tape of the MT deck 36 is previously determined.
Integrated circuit pattern data recorded in the
Beam focused on a predetermined portion of the metal layer 3 based on the
And the metal layer 3 is etched. At this time, the pixel
The irradiation time per hit is, for example, 3 × 10^-6Second, beam
The number of scans is about 30 times. Thus, FIG.
As shown in (b), the metal layer 3 is patterned.
The pattern formation of the metal layer 3 is performed as in the first embodiment.
Alternatively, an electron beam exposure method may be used. Thereafter, the illustration formed on the mask 1b is not shown.
A predetermined amount of ion beam onto the alignment mark,
The generated secondary electrons are sent to the secondary ion / secondary electron detector 20.
Detection mark and the alignment mark
Is calculated. Then, the position of the calculated alignment mark is calculated.
Ion beam irradiation based on the setting coordinates
Is applied to the position where the phase shift groove 7a is formed.
Next, the sample table 16 is moved. Next, the pattern data of the phase shift groove 7a is
Of the metal layer 3 along the edge of the metal layer 3 based on the
The substrate 2 exposed by the ion beam formation with an ion beam
Then, a phase shift groove 7a (FIG. 4) is formed. At this time,
According to the bundle ion beam, the depth and width of the phase shift groove 7a
Can be easily controlled. In the second embodiment, the phase
The pattern data of the shift groove 7a is, for example, an integrated circuit pattern.
The transparency obtained by inverting the pattern data of the turn
Pattern data of over-area B and pattern width of light-shielded area A
AND with the pattern data obtained by fattening (AN
D) is automatically created by taking
ing. That is, the pattern data of the phase shift groove 7a
Data is not created specifically,
Is automatically created based on the pattern data. Using the mask 1b manufactured in this manner,
And a mask 1 is placed on the photoresist-coated wafer.
To transfer the integrated circuit pattern on b, for example,
To do. That is, a reduction projection exposure apparatus (not shown)
The mask 1b and the wafer are arranged and the collection on the mask 1b is performed.
Optical reduction of integrated circuit pattern to 1/5
While projecting, the wafer is sequentially moved stepwise.
By repeatedly performing projection exposure every time, the entire wafer is exposed.
The integrated circuit pattern is transferred onto the surface. Next, the operation of the mask 1b according to the second embodiment will be described.
Will be described with reference to FIGS. A predetermined collection on the mask 1b shown in FIG.
During the exposure process to transfer the original image of the integrated circuit pattern, the mask
In each transmission region B of FIG.
Between the transmitted light and the light transmitted through the normal transmission area B
Produces a phase difference of 180 degrees (FIG. 7B,
(C)). The phase shift groove 7a is formed in each metal layer 3
, So that it transmits through one transmission area B.
Light transmitted through the phase shift groove 7a and the normal light
The light transmitted through the transmission area B is blocked by the light adjacent to the transmission area B.
At the boundary between the light regions A, A weaken each other. Therefore, the module of the light intensity distribution on the wafer
This greatly improves the simulation (FIG. 7D). Special
The edge of each light shielding area A projected on the wafer
Injury is greatly reduced and the pattern projected on the wafer
Transfer accuracy is greatly improved. Note that the light intensity is the square of the light amplitude.
The waveform on the negative side of the light amplitude on the wafer is shown in FIG.
As shown in (d), it is inverted to the positive side. The mask 1b according to the second embodiment
However, as in the first embodiment, one transmission region B is
It is a technology that considers only the phase difference in transmitted light
Therefore, a complicated integrated circuit pattern is formed on the mask 1b.
However, the arrangement of the phase shift groove 7a is easy,
The pattern data of the shift groove 7a is composed of an integrated circuit pattern.
Pattern data of the light-shielding area A or the transparent area B to be formed
Can be automatically created based on the In addition, the mask 1b of the second embodiment
At the time of manufacture, the phase described in the first embodiment is changed.
There is no step of forming the transparent film 4a to be shifted,
Patterning metal layer 3 by ion beam
At this time, the phase shift groove 7a is also formed at the same time.
Can be further shortened. As described above, according to the second embodiment, the following effects can be obtained.
Fruit can be obtained. (1) In each transmission area B of the mask 1b, a phase shift
Light transmitted through the groove 7a and transmitted through the normal transmission region B
There is a 180 degree phase difference between the light and the
To weaken each other at the boundary between the area A and the transmission area B,
Significantly improved modulation of light intensity distribution on wafer
Is done. In particular, the pattern of the light shielding area A projected on the wafer
The blur at the edges of the image is greatly reduced,
The degree can be greatly improved. (2) The pattern formed on the mask by (1) above
However, even if it is a fine and complicated integrated circuit pattern,
The transfer accuracy of the pattern image does not decrease
The transfer accuracy of all turns can be improved. (3). The phase shift groove 7a has transmitted one transmission area B.
Complex integration because this technology only considers the phase difference of light
Even a circuit pattern can be easily arranged. (4) According to the above (3), the pattern data of the phase shift groove 7a is
The light shielding area A constituting the integrated circuit pattern
Automatically created based on the pattern data of excess area B
Therefore, it is easy to make the mask 1b
Can be manufactured in a short time. (5) For the mask 1b, the manufacturing method
The transparent film 4a for shifting the phase described in 1 is formed.
There is no process, and the metal layer 3 is patterned by a focused ion beam.
At the time of cleaning, a phase shift groove 7a is also formed.
The production time can be further reduced.
Wear. (6) In the mask 1b, the transparent film 4a is patterned.
It does not deteriorate due to the subsequent cleaning process, etc.
The width can be improved. (Embodiment 3) FIG. 8 shows still another embodiment of the present invention.
FIG. 9 is a cross-sectional view of a main part of a mask according to the third embodiment.
FIG. 10 (a) is a plan view of a main part of the disk, and FIG.
FIGS. 10B to 10D are cross-sectional views showing the exposure state of the mask.
The amplitude and intensity of the light transmitted through the transmission area of this mask
FIG. First, this embodiment will be described with reference to FIGS. 8 and 9.
The third mask 1c will be described. It should be noted that Embodiment 3
Therefore, as shown in FIG. 9, the shape of the transmission area B is rectangular.
I will explain. The mask 1c of the third embodiment is, for example,
Wafer not shown in predetermined manufacturing process of semiconductor device
With a 5x reticle that transfers a predetermined integrated circuit pattern onto it
The metal layer 3 constituting the light shielding area A has
A plurality of grooves 37 extending from the upper surface of the substrate 3 to the main surface of the substrate 2
Have been. The groove 37 is, as shown in FIG.
Each side of the transmission area B so as to surround the transmission areas B
Are arranged in parallel along. In addition, for example, the groove 37
Is about 0.5 μm. Further, for example, a refraction
Transparent film made of indium oxide (InOx) with a ratio of 1.5
4b, and at the time of exposure, this transparent film 4b,
And light transmitted through the groove 37 and light transmitted through the transmission area B.
And a phase difference is generated between them. Then, the transparent film 4b is viewed from the main surface of the substrate 2
The thickness X2 is the same as in the first embodiment,
1c, the transparent film 4b and the groove 37 are formed.
The phase of the transmitted light and the phase of the light transmitted through the transmission region B
To produce a phase difference of 180 degrees between X2 = λ /
[2 (n-1)].
You. For example, the wavelength λ of the light irradiated at the time of exposure is set to 0.
When the thickness is 365 μm (i-line), the main
The thickness X2 from the surface may be about 0.37 μm. Although not shown, the mask 1c includes:
For example, when forming the groove 37 and the transparent film 4b,
The alignment mark for aligning with the genus layer 3
Is formed. To manufacture such a mask 1c, for example,
For example, First, the main surface of the polished and cleaned substrate 2 is covered.
Thus, for example, a metal layer 3 of 500 to 3000
After forming it by the method such as
2 in the holder 15 of the focused ion beam device 8 described in
Hold. Next, the magnetic tape of the MT deck 36 is
Based on the integrated circuit pattern data recorded in
The metal layer 3 covering the main surface of the substrate 2 is patterned by an ion beam.
Formed. Thereafter, the magnetic tape of the MT deck 36 is also used.
Based on the pattern data of the groove 37 recorded in advance in the
And irradiates the metal layer 3 on the main surface of the substrate 2 with an ion beam.
Then, a groove 37 is formed in the metal layer 3. This groove 37 putter
The data is, for example, the groove 3 for the rectangular transmission area B.
By setting the arrangement rule of 7, it is automatically created
It has become so. Then, the pattern data of the integrated circuit pattern
And a pattern created based on the pattern data of the groove 37.
Based on the pattern data of the bright film 4b,
Similarly, a transparent film 4b is formed. Next, the operation of the third embodiment will be described with reference to FIG.
This will be described with reference to (d). A predetermined area on the mask 1c shown in FIG.
The original image of the integrated circuit pattern is wafer
When transferring to the upper side, the light is transferred to each transmission area B of the mask 1c.
The light transmitted through the transparent film 4b and the groove 37 and the transmission area
A phase difference of 180 degrees is generated between the light transmitted through B and the light transmitted through B.
(FIGS. 10B and 10C). The light transmitted through one transmission area B is
Of these, the light transmitted through the transparent film 4b and the groove 37 and the transmission area
The light transmitted through the region B is a light shielding region adjacent to the transmission region B.
A, Weak at the ends of A. Therefore, the model of the light intensity distribution on the wafer
This greatly improves the simulation (FIG. 10D). Special
The edge of each light shielding area A projected on the wafer
Injury is greatly reduced and the pattern projected on the wafer
Transfer accuracy is greatly improved. Note that the light intensity is the square of the light amplitude.
The waveform on the negative side of the light amplitude on the wafer is shown in FIG.
As shown in (d), it is inverted to the positive side. Further, the mask 1c of the third embodiment
However, the phase difference of the light transmitted through one transmission region B
Only the grooves 37 and the transparent film 4b need to be considered.
It is easy to install the groove 37 and the pattern of the transparent film 4b.
Data into a rectangular transparent area that constitutes the integrated circuit pattern.
Automatically created based on pattern data of B
it can. As described above, according to the present embodiment, the following effects can be obtained.
Fruit can be obtained. (1) In each transmission area B of the mask 1c, the transparent film 4
b, the light transmitted through the groove 37 and the light transmitted through the transmission area B.
There is a 180 degree phase difference between the light and the
Since the light is weakened at the end of the area A, the light intensity
Fabric modulation is greatly improved. In particular,
C. Blurring of the end of the pattern image of the light-shielded area A projected on the top
Is greatly reduced, and the pattern transfer accuracy is greatly improved.
Can be (2) The pattern formed on the mask by (1) above
However, even if it is a fine and complicated integrated circuit pattern,
The pattern transfer accuracy does not decrease
The transfer accuracy of all turns can be improved. (3) The transparent film 4b for shifting the phase and the groove 37 are
Technique that considers only the phase difference of the light transmitted through the two transmission areas B
Technology, even complex integrated circuit patterns
Arrangement becomes easy. (4) According to the above (3), the pattern of the groove 37 and the transparent film 4b is formed.
Data from the light shielding area A, which constitutes the integrated circuit pattern,
Or automatically based on the pattern data of the transparent area B
Can be created. (5) According to the above (3) and (4), the pattern data of the transparent film 4b is obtained.
Phase shift because you can create
The mask 1c on which the transparent film 4b and the groove 37 are formed is shortened.
Can be manufactured in time. (Embodiment 4) FIG. 11 shows still another embodiment of the present invention.
FIG. 12 is a sectional view of a main part of a mask showing another embodiment.
13 (a) is a plan view of a main part of the mask of FIG.
FIG. 13B is a cross-sectional view showing an exposure state of the mask 12.
(D) shows the amplitude and intensity of the light transmitted through the transmission region.
FIG. First, the present embodiment will be described with reference to FIGS.
The mask 1d according to mode 4 will be described. In the mask 1d according to the fourth embodiment,
At the time of exposure, light transmitted through the groove 37 and transmitted light through the transmission region B
As a means for generating a phase difference with light, an embodiment
3 instead of the transparent film 4b of FIG.
A shift groove 7b is formed. The depth d of the phase shift groove 7b is determined according to the embodiment.
As in the case of 2, the light beam applied to the mask 1b during the exposure
That is, the phase of light transmitted through the groove 37 and the phase shift groove 7b
Between the phase of light transmitted through the transmission region B and
In order to generate a phase difference, d = λ / [2 (n−1)]
It is formed to satisfy the relationship. For example, the wavelength of light
If λ is 0.365 μm (i-line), the phase shift groove
The depth d of 7b may be about 0.39 μm. Further, in Embodiment 4, FIG.
As shown in FIG. 2, for example, at the four corners of the rectangular transmission area B,
For example, a rectangular sub-transmissive area of 0.5 × 0.5 μm
(In-phase auxiliary transmission region) C is provided. This is an accumulation
Formed on wafers after development as circuit patterns become finer
The four corners of the pattern line to be
Unlike the original image of the road pattern, it is not square but rounded
This is in order to prevent a malfunction such as swelling. That is,
In integrated circuit patterns, the light intensity is most likely to decrease,
A sub-transmissive area C is set at the corner where the distortion becomes large.
Pattern image projected with increased light intensity near corners
Has been corrected. Although not shown, the mask 1d includes:
For example, when forming the groove 37 and the sub-transmission area C,
Alignment mark for aligning the metal layer 3 with the metal layer 3
Is formed. Further, in manufacturing such a mask 1d,
Is to etch the metal layer 3 with an ion beam
7 is formed, the number of times of ion beam scanning is increased,
The plate 2 may be etched by the depth d. Next, the operation of the fourth embodiment will be described with reference to FIG.
This will be described with reference to (a) to (d). A predetermined pattern on the mask 1d shown in FIG.
Original pattern of integrated circuit pattern on wafer by reduced exposure method
Is transferred to each transmission area B of the mask 1d.
Light transmitted through the groove 37 and the phase shift groove 7b,
There is a 180 degree phase difference between the light transmitted through the
(FIGS. 13B and 13C). The light transmitted through one transmission area B is
Of which, the light transmitted through the groove 37 and the phase shift groove 7b;
The light transmitted through the transmission area B is blocked by the light adjacent to the transmission area B.
The optical regions A, A weaken each other at the ends. Therefore, the light intensity distribution on the wafer
This greatly improves the simulation (FIG. 13D). Special
The edge of each light shielding area A projected on the wafer
Injuries are greatly reduced and the corners of the rectangular transmission area B
The formed sub-transmission area C increases the light intensity near the corner.
Transfer of the pattern image projected on the wafer
The accuracy is further improved. Note that the light intensity is the square of the light amplitude.
Therefore, the waveform on the negative side of the light amplitude on the wafer is shown in FIG.
As shown in (d), it is inverted to the positive side. Further, in the mask 1d of the fourth embodiment,
However, the phase difference of the light transmitted through one transmission region B
Only the depth of the groove 37 can be easily determined.
The pattern data of the groove 37 is used to construct an integrated circuit pattern.
The groove 37 is arranged with respect to the pattern of the rectangular transparent area B.
By setting the placement rules,
And it is possible. In Embodiment 4, Embodiment 3
In addition to the effects shown in (1) to (5), the manufacturing of the mask 1d
In this case, the transparent film for shifting the phase described in the third embodiment
4b is not formed, and the focused ion beam
Phase shift when patterning the metal layer 3
Since the groove 7b can also be formed, the manufacturing time can be further reduced.
Can be made. In the mask 1d, the embodiment
Cleaning work after formation of transparent film 4b of mask 1c in state 3
The life of the mask 1d is greatly increased because there is no deterioration
Can be improved. As described above, the invention made by the present inventor is realized.
Although specifically described based on the embodiment, the present invention
It is not limited to the embodiment but deviates from its gist.
Needless to say, various changes can be made within the range that does not exist. For example, in the mask of the first embodiment,
A transparent film that shifts the phase from the contour of the metal layer
Explain the case where it is arranged so that it partially protrudes into the excess area.
, But is not limited to this.
As shown in a mask 1e shown in FIG.
The transparent film 4c may be disposed on the surface. Also in this case, FIGS.
As shown in (d), each of the masks 1e (FIG. 16 (a))
Light transmitted through the transparent film 4c in each of the transmission areas B, B
And 180 degrees between the light transmitted through the normal transmission region B
(FIGS. 16 (b) and 16 (c)), and one transmission
Of the light transmitted through the region B, the light transmitted through the transparent film 4c is
The light transmitted through the normal transmission region B is adjacent to the transmission region B.
At the boundary between the light-shielding areas A, A
The modulation of the light intensity distribution on the wafer (modula
is greatly improved (FIG. 16D). The pattern of the transparent film 4c in this case is
The data is, for example, pattern data of an integrated circuit pattern.
The pattern of the light-shielded area obtained by inverting the
What is necessary is to make it by making it. In the mask according to the second embodiment,
When the phase shift groove is arranged along the edge of the metal layer,
However, the present invention is not limited to this.
For example, as shown in a mask 1f shown in FIG.
The phase shift groove 7c may be formed and arranged near the center. This
In the case of, the same operation as the operation shown in FIGS.
Use is obtained. Further, for example, an integrated circuit such as a memory cell is used.
In the part where the road pattern is simply arranged,
A pair sandwiching the light shielding region A like a mask 1g shown in FIG.
A phase shift groove 7d in at least one of the transmission regions B
May be formed. This means that the phase of light is shifted.
In addition, a transparent film is provided on one of a pair of conventional transmission regions.
Same as technology, but without transparent material
In addition to greatly reducing the manufacturing time,
Since there is no deterioration due to cleaning after formation, the life of the mask
Has an effect that can be greatly improved. In the third and fourth embodiments, the transmission
The case where the area is rectangular has been described.
It is not specified, even if it is a complicated shape
I can respond. Further, in Embodiments 1 and 3, the transparent film
Was described as indium oxide.
It is not limited to magnesium fluoride, poly
Methyl methacrylate may be used. In the above description, mainly the present inventor has described
Of the inventions made
When applied to masks used in the manufacturing process of body devices
Although described above, the present invention is not limited to this, and various applications are possible.
Microlithography on a given substrate by photolithography technology.
Need to transfer fine and complex patterns
Applicable to technical fields. [0123] According to the invention disclosed by the present application,
To briefly explain the effects that can be achieved by tabular objects,
It is as follows. That is, according to the present invention,Mask substrate
Providing and an integrated circuit pattern on the mask substrate.
Alignment when forming phase and phase shifter patterns
For forming a light-shielding film having alignment marks used for
And the alignment mark provided on the light shielding film.
Irradiating the mask substrate with an ion beam based on the
And the phase shifter
Forming a turnThe phase shift
Mask that enables good alignment between the mask pattern and the light-shielding film
Can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a main part of an optical mask according to an embodiment of the present invention. FIGS. 2A to 2C are main-portion cross-sectional views of the optical mask showing a manufacturing process of the optical mask. 3A is a cross-sectional view illustrating an exposure state of the optical mask of FIG. 1, and FIGS. 3B to 3D are explanatory diagrams illustrating amplitude and intensity of light transmitted through a transmission region of the optical mask. is there. FIG. 4 is a cross-sectional view of a main part of an optical mask according to another embodiment of the present invention. FIGS. 5A and 5B are cross-sectional views of a main part of the optical mask showing a manufacturing process of the optical mask. FIG. 6 is a configuration diagram of a focused ion beam device used when manufacturing the optical mask. 7A is a cross-sectional view illustrating an exposure state of the optical mask of FIG. 4, and FIGS. 7B to 7D are explanatory diagrams illustrating amplitude and intensity of light transmitted through a transmission region of the optical mask. is there. FIG. 8 is a cross-sectional view of a main part of an optical mask according to still another embodiment of the present invention. FIG. 9 is a plan view of a main part of the optical mask. 10A is a cross-sectional view showing an exposure state of the optical mask of FIGS. 8 and 9, and FIGS. 10B to 10D show amplitude and intensity of light transmitted through a transmission region of the optical mask. FIG. FIG. 11 is a cross-sectional view of a main part of an optical mask showing still another embodiment of the present invention. FIG. 12 is a plan view of a main part of the optical mask. FIG. 13A is a cross-sectional view of the optical mask of FIGS. 11 and 12, and FIGS. 13B to 13D are explanatory diagrams showing the amplitude and intensity of light transmitted through a transmission region of the optical mask. . FIG. 14 is a cross-sectional view of a main part of an optical mask according to still another embodiment of the present invention. FIG. 15 is a sectional view of a main part of an optical mask according to still another embodiment of the present invention. 16A is a cross-sectional view showing an exposure state of the optical mask of FIG. 14, and FIGS. 16B to 16D show amplitude and intensity of light transmitted through a transmission region of the optical mask shown in FIG. FIG. FIG. 17 is a sectional view of a main part of an optical mask according to still another embodiment of the present invention. 18A is a cross-sectional view illustrating an exposure state of a conventional optical mask, and FIGS. 18B to 18D are explanatory diagrams illustrating amplitude and intensity of light transmitted through a transmission region of the conventional optical mask. is there. 19A is a cross-sectional view illustrating an exposure state of a conventional optical mask, and FIGS. 19B to 19D are explanatory diagrams illustrating amplitude and intensity of light transmitted through a transmission region of the conventional optical mask. is there. FIG. 20 is a partial plan view showing a conventional optical mask. DESCRIPTION OF SYMBOLS 1a to 1g Mask 2 Mask substrate 3 Metal layers 4a to 4c Transparent films 5a and 5b Photoresist 6 Antistatic layers 7a to 7d Phase shift grooves 8 Focused ion beam device 9 Ion source 10 Extraction electrodes 11a and 11b 1. Second lens electrodes 12a to 12c First to third aperture electrodes 13 Blanking electrodes 14 Deflection electrodes 15 Holder 16 Sample stage 17 Laser mirror 18 Laser interferometer 19 Sample stage drive motor 20 Secondary ion / secondary Electron detector 21 Electron shower radiation unit 22 Vacuum pump 23-27 Control unit 28-32 Interface unit 33 Control computer 34 Terminal 35 Magnetic disk unit 36 MT deck 37 Groove A Light shielding area B Transmission area C Sub transmission area (in-phase auxiliary transmission) Area) E Electron beam 50, 51 Conventional mask 52 Transparent material 53 Integrated circuit patterns P1 to P3 Transmission areas N to N3 in conventional mask Light shielding area in conventional mask

Continuation of front page (56) References JP-A-58-173744 (JP, A) JP-A-61-292643 (JP, A) JP-A-56-38475 (JP, A) JP-A-63-10162 (JP) JP-A-62-92438 (JP, A) JP-A-62-189468 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 1/00-1/16

Claims (1)

(57) Claims 1. A step of preparing a mask substrate, and light shielding having alignment marks used for alignment when forming an integrated circuit pattern and a phase shifter pattern on the mask substrate. Forming a film , based on the alignment mark provided on the light-shielding film.
Irradiating the mask substrate with an ion beam.
Forming the phase shifter pattern by excavating the mask substrate .