JP2000138165A - Electric charge particle plotter and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fatal deformation in a circuit pattern without lowering throughput even if a connection error occurs between partial irradiation regions. SOLUTION: At first, until forming beams 21 reach from a region at a lower left corner of a circuit pattern 16a to an upper left region, a substrate stage 12 and a mask stage 17 are continuously moved to a -Y direction, while the forming beams 21 are irradiated, thereby obtaining a partial irradiation region 22. After the forming beams 21 reached an upper left region of the circuit pattern 16a, the substrate stage 12 and mask stage 17 are slid to a -X direction by a pitch P. Until the forming beams 21 reach from an upper end part of the circuit pattern 16a to a lower end thereof, the substrate stage 12 and mask stage 17 are continuously moved to a +Y direction. At this time, the forming beams 21 are formed so that an irradiation amount of a double irradiation part 22a of the partial irradiation region 22 is equaled with that of a non-double irradiation part 22b thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle drawing method for drawing a design pattern formed on a mask on a substrate by using charged particles when manufacturing a semiconductor device, a liquid crystal display device or a thin film magnetic head device. The present invention relates to a charged particle drawing apparatus.

[0002]

2. Description of the Related Art At present, a photolithography technique used for manufacturing semiconductor devices and the like uses a KrF having a wavelength of 248 nm.
Excimer laser light is used as a light source. As a next-generation optical lithography technology, ArF having a wavelength of 193 nm is used.
Excimer laser lithography is about to be adopted. However, when further miniaturization is promoted, the resolution between design patterns is limited by the optical lithography technology.

[0003] Therefore, various lithography techniques have been proposed, among which charged particles such as ions and electrons,
In particular, a drawing technique using an electron beam has attracted attention.
Among the drawing techniques using an electron beam, there are a method using a mask on which a design pattern is drawn and a method using no mask.

The outline of a conventional electron beam writing method using a mask will be described below with reference to the drawings. FIG. 19 shows a conventional electron beam writing method, in which a mask 101 on which a desired circuit pattern 102 is formed is irradiated with an electron beam 103 while scanning. As shown in FIG. 19, an electron beam emitted from an electron gun is passed through a shaping aperture (not shown) to be shaped into, for example, an electron beam having an area of about 1 mm × 1 mm. Circuit pattern 102
Is irradiated on the mask 101 on which is formed. The electron beam that has passed through the mask 101 is reduced by an electron lens and irradiated onto a resist-coated substrate (not shown). Usually, the circuit pattern 102 is sufficiently larger than the dimension of the shaping aperture. Therefore, as shown in FIG.
01 is continuously moved, and after scanning from one end to the other end of the circuit pattern 102, the effective width of the forming aperture is repeated with a pitch (= P), so that the electron beam 103 is strip-shaped over the entire surface of the circuit pattern 102. To be irradiated.

[0005]

However, according to the conventional electron beam writing method, for example, as shown in FIG. Partial irradiation area 10 which is an area
There is a problem that a connection error occurs between 4A, 104B, and 104C. Here, the first partial irradiation area 10
4A and the second partial irradiation area 104B are apart from each other, and the second partial irradiation area 104B and the third partial irradiation area 104C overlap each other. This is due to the positioning accuracy of the stage holding the substrate or the mask and the stability of the electron beam.

When a connection error occurs between the partial irradiation areas,
For example, as shown in FIG. 21A, in a wiring pattern straddling a connection portion between partial irradiation regions, disconnection occurs when the partial irradiation regions are separated from each other, as shown in FIG.
As shown in (b), when the distance is short, a dimensional abnormality that is locally thinned occurs, which may cause disconnection. Furthermore, as shown in FIG. 21C, when the partial irradiation regions overlap, a dimensional abnormality that locally increases in thickness occurs, which leads to a defective circuit pattern.

The present invention has been made in consideration of the above-described conventional problems, and has as its object to prevent a fatal deformation of a circuit pattern without reducing throughput even if a connection error occurs between partial irradiation regions. I do.

[0008]

In order to achieve the above-mentioned object, the present invention provides a method of irradiating a part of an irradiation area so as to be double when repeating partial transfer to a mask design pattern. The irradiation amount of the beam in the irradiation region and the irradiation amount of the beam in the normal irradiation region not irradiating doubly are made equal to each other.

Specifically, the charged particle writing method according to the present invention comprises a beam forming step of forming an output beam emitted from a charged particle generation source into a predetermined shape,
The design pattern on the substrate is repeated by transmitting a part of the design pattern of the mask having the design pattern and irradiating the transmitted beam on a part of the substrate to transfer a part of the design pattern onto the substrate. And a design pattern transfer step of transferring, wherein the design pattern transfer step forms a double irradiation part in which a part of an irradiation area irradiated with a beam on the substrate is double-irradiated when performing partial transfer. And irradiating so that the irradiation amount of the beam of the double irradiation part and the non-double irradiation part which is not double irradiated in the irradiation area is substantially the same.

According to the charged particle drawing method of the present invention, when the partial transfer is repeated in the design pattern transfer step,
Since the irradiation area on the substrate is formed with a double irradiation part in which a part of the irradiation area is double-irradiated, a margin for moving the beam is increased, so that the irradiation areas are hardly separated from each other. In addition, since irradiation is performed so that the beam irradiation amount of the double irradiation part and the non-double irradiation part that is not double-irradiated in the irradiation area is substantially the same, there is no dimensional abnormality in the design pattern in the double irradiation part. Does not occur. Further, even if the irradiation regions are shifted from each other, the irradiation amount does not become 0, and the irradiation amount does not double even if the overlapping portion becomes large. As a result, disconnection or deformation of the resist pattern due to a connection error when the partial irradiation is repeated can be prevented, and the performance and yield of the semiconductor device can be improved.

In the charged particle writing method according to the present invention, the beam forming step includes the step of forming the output beam into a line connecting an end of the double irradiation section on the side of the non-double irradiation section and an end of the double irradiation section on the side opposite to the non-double irradiation section. At the midpoint of the minute, the step of shaping so that the irradiation amount of the output beam is about one half of the irradiation amount for the non-double irradiation part. It is preferable to include a step of scanning in a band shape on the above. With this configuration, even when the scanning irradiation is performed, the irradiation amount of the double irradiation unit can be made substantially the same as the irradiation amount of the non-double irradiation unit.

In the charged particle writing method according to the present invention, the beam shaping step includes the step of changing the output beam from the double irradiation section to 0 at the end opposite to the non-double irradiation section and to the non-double irradiation. Including a step of continuously changing so as to be a predetermined amount at the end on the irradiation unit side, the design pattern transfer step,
Preferably, the method includes a step of scanning the shaped beam in a band shape on the mask and the substrate. With this configuration, even when the scanning irradiation is performed, the irradiation amount of the double irradiation unit can be made substantially the same as the irradiation amount of the non-double irradiation unit.

In the charged particle writing method according to the present invention, the beam shaping step is performed such that the irradiation amount of the outgoing beam in the double irradiation portion is about one half of the irradiation amount in the non-double irradiation portion. In the design pattern transfer step, the beam formed on a portion of the mask and the substrate is irradiated in a stopped state, and then the end of the beam irradiation area on the beam moving direction side in the irradiation area irradiated with the beam is also included. It is preferable to include a step of moving the film so as to perform double irradiation. In this way, even when the step-and-repeat irradiation is performed, the irradiation amount of the double irradiation unit can be made substantially the same as the irradiation amount of the non-double irradiation unit.

When performing step-and-repeat type irradiation, the beam shaping step is to change the output beam at the four corners of the irradiation area so that the irradiation amount of the output beam of the double irradiation portion is about 4 times the irradiation amount of the non-double irradiation portion. It is preferable to include a step of molding to be one-half. By doing so, even when performing step-and-repeat irradiation,
Even if the double irradiation part at the four corners of the irradiation area is irradiated four times, the irradiation amount of the double irradiation part can be made substantially the same as the irradiation amount of the non-double irradiation part.

In the charged particle writing method of the present invention, it is preferable that the width of the double irradiation portion is smaller than about one hundredth of the movement width of the irradiation region when the partial transfer is repeated. In this way, a decrease in throughput can be suppressed.

In the charged particle writing method of the present invention, it is preferable that the width of the double irradiation part is smaller than about one hundredth of the width of the irradiation area. In this way, a decrease in throughput can be reliably suppressed.

A first charged particle drawing apparatus according to the present invention comprises:
On the substrate, using a beam of charged particles, irradiate a part of the design pattern of the mask having the design pattern,
A charged particle generating device for drawing a design pattern on a substrate by repeating irradiation while overlapping a part of the portion, a charged particle generating means for emitting a beam toward the substrate, and a substrate holding device for holding the substrate Means, a mask holding means for holding the mask between the charged particle generation means and the substrate, and a molding provided between the charged particle generation means and the mask held by the mask holding means for shaping the beam into a predetermined shape. An aperture, a mask holding means and a moving means for relatively moving the substrate holding means and the charged particle generation means, and the shaping aperture is provided on an irradiation area of the substrate irradiated with a beam transmitted through the mask, a double irradiation. When forming a double-irradiated part to be irradiated and a non-double-irradiated part that is not doubly-irradiated, the beam irradiation amounts of the double-irradiated part and the non-double-irradiated part are substantially equal. It has become such openings pattern.

According to the first charged particle lithography system, a double irradiation portion is formed, which irradiates the irradiation region of the substrate with the beam transmitted through the mask in a double manner.
Since the margin when moving the beam is increased, it is difficult for the irradiation regions to separate from each other. Further, since the forming aperture has an opening pattern such that the irradiation amount of the beam of the double irradiation part and the non-double irradiation part which is not double irradiated in the irradiation area is substantially the same, the double irradiation part No dimensional abnormality occurs in the design pattern. In addition, even if the irradiation regions are shifted from each other, the irradiation amount does not become 0, and the irradiation amount does not double even if the overlapping portion becomes large. As a result, disconnection or deformation of the resist pattern due to a connection error when the partial irradiation is repeated can be prevented, and the performance and yield of the semiconductor device can be improved.

In the first charged particle drawing apparatus, the aperture ratio of the area corresponding to the double irradiation portion of the aperture pattern is approximately 50.
%, And the aperture ratio of the area corresponding to the non-double irradiation part of the aperture pattern is preferably about 100%. With this configuration, the irradiation amount of the double irradiation unit in the irradiation region can be made equal to the irradiation amount of the non-double irradiation unit.

In this case, it is preferable that the opening pattern has a parallelogram shape in which sides of a region corresponding to the double irradiation portion in the opening pattern are oblique sides facing each other. With this configuration, the irradiation amount of the double irradiation unit in the irradiation region can be made substantially the same as the irradiation amount of the non-double irradiation unit.

In this case, it is preferable that the opening pattern has a trapezoidal shape in which sides of a region corresponding to the double irradiation portion in the opening pattern are oblique sides facing each other. With this configuration, the irradiation amount of the double irradiation unit in the irradiation region can be made substantially the same as the irradiation amount of the non-double irradiation unit.

In the first charged particle writing apparatus, the transmittance of the area corresponding to the double irradiation part of the aperture pattern is approximately 50%.
%, And the transmittance of the area corresponding to the non-double irradiation part of the opening pattern is preferably about 100%. With this configuration, the irradiation amount of the double irradiation unit in the irradiation region can be made substantially the same as the irradiation amount of the non-double irradiation unit.

A second charged particle drawing apparatus according to the present invention comprises:
On the substrate, using a beam of charged particles, irradiate a part of the design pattern of the mask having the design pattern,
A charged particle generating device for drawing a design pattern on a substrate by repeating irradiation while overlapping a part of the portion, a charged particle generating means for emitting a beam toward the substrate, and a substrate holding device for holding the substrate Means, a mask holding means for holding the mask between the charged particle generating means and the substrate, and a moving means for relatively moving the mask holding means, the substrate holding means and the charged particle generating means, and Means for forming a double-irradiated portion that is double-irradiated and a non-double-irradiated portion that is not double-irradiated in an irradiation region irradiated with a beam transmitted through the mask on the substrate; A plurality of charged particle sources having an arrangement such that the beam irradiation amounts of the unit and the non-double irradiation unit are substantially the same.

According to the second charged particle lithography system, a double irradiation portion is formed, which irradiates the irradiation region of the substrate with the beam transmitted through the mask twice.
Since the margin when moving the beam is increased, it is difficult for the irradiation regions to separate from each other. Further, the charged particle generation means has a plurality of charged particle generation sources having an arrangement such that the beam irradiation amounts of the double irradiation portion and the non-double irradiation portion which are not double irradiated in the irradiation area are substantially the same. Therefore, no dimensional abnormality occurs in the design pattern in the double irradiation part. Further, even if the irradiation regions are shifted from each other, the irradiation amount does not become 0, and the irradiation amount does not double even if the overlapping portion becomes large. As a result, disconnection or deformation of the resist pattern due to a connection error when repeating partial irradiation can be prevented, and the performance and yield of the semiconductor device can be improved.

In the second charged particle writing apparatus, the charged particle generation source in the area corresponding to the double irradiation part in the charged particle generation means is compared with the charged particle generation source in the area corresponding to the non-double irradiation part. Emission energy of charged particles is almost 50%
It is preferred that With this configuration, the irradiation amount of the double irradiation unit in the irradiation region can be made substantially the same as the irradiation amount of the non-double irradiation unit.

In the second charged particle drawing apparatus, the number of charged particle generation sources in the beam moving direction in the area corresponding to the double irradiation section in the charged particle generating means is such that the charged area in the area corresponding to the non-double irradiation section is charged. It is preferable that the number is approximately one half of the number of the particle generation sources. With this configuration, the irradiation amount of the double irradiation unit in the irradiation region can be made substantially the same as the irradiation amount of the non-double irradiation unit.

In the first or second charged particle drawing apparatus, the mask holding means is a mask stage, the substrate holding means is a substrate stage, and the moving means moves the mask stage and the substrate stage in synchronization with each other. Is preferred. In this case, when the charged particle beam for irradiation and the mask and the substrate are relatively moved, it is easier to move each stage than to move the charged particle beam and to move the stage widely. In addition, the design pattern of the mask can be reliably transferred onto the substrate.

[0028]

(First Embodiment) A first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows a front configuration of a charged particle drawing apparatus according to a first embodiment of the present invention. FIG.
As shown in FIG. 1, a semiconductor substrate 11 having a resist film applied on the upper surface is placed on a movable substrate stage 12,
Above the substrate stage 12, an electron gun 13 as charged particle generating means for emitting an electron beam toward the upper surface of the semiconductor substrate 11 is provided. A first deflecting lens 14 is provided between the electron gun 13 and the substrate stage 12 in order from the top.
A, a shaping aperture 15 for shaping an accelerated electron beam emitted from the electron gun 13, a second deflecting lens 14B,
Mask 16 on which a circuit pattern as design information is formed
And a deflecting / reducing lens 14C. In this apparatus, the electron gun 13 is fixed and the mask 16
Is connected to a mask stage 17 that moves in synchronization with the substrate stage 12.

FIG. 2 shows how the shaping beam 21 shaped into a predetermined shape by the shaping aperture 15 is scanned on the circuit pattern 16a of the mask 16. As shown in FIG. 2, since the area of the circuit pattern 16 a is usually sufficiently larger than the area of the opening pattern 15 a of the forming aperture 15, it is necessary to draw the entire circuit pattern 16 a on the semiconductor substrate 11. All of 16a need to be irradiated with the shaping beam 21. here,
In order to realize this, a scanning method in which the mask 16 is continuously moved is adopted.

The procedure for scanning the shaped beam 21 will be described below.

As shown in FIG. 2, it is assumed that the pattern is drawn from the lower left of the circuit pattern 16a of the mask 16. First, the mask stage 17 and the substrate stage 12 are moved so that the region at the lower left corner of the circuit pattern 16a to be drawn coincides with the irradiation region of the electron beam passing through the shaping aperture 15. In FIG. 2, the electron gun 13 of the drawing apparatus, that is, the shaping beam 21 is fixed, but for simplicity of explanation, the mask 16 is fixed and the shaping beam 21 is shown to move in the direction of the arrow. .

Next, the shaped beam 21 is applied to the circuit pattern 16.
By irradiating the forming beam 21 while continuously moving the substrate stage 12 and the mask stage 17 in the −Y direction from the lower left corner region to the upper left region of “a”, the partial irradiation region 22 is obtained. Here, the forming beam 21
Is the maximum width, and the moving amount of the shaping beam 21 for irradiating the next partial irradiation area 22 is the pitch P.

Next, the forming beam 21 is applied to the circuit pattern 16.
After reaching the upper left area of “a”, the substrate stage 12 and the mask stage 17 are shifted in the −X direction by the pitch P.

Next, the shaped beam 21 is applied to the circuit pattern 16.
a until the substrate stage 12 reaches the lower end from the upper end.
And the mask stage 17 is continuously moved in the + Y direction. Here, instead of scanning in such a zigzag manner, scanning may be performed in the same direction as the first partial irradiation area 22. In addition, the conventional forming aperture generally has a square opening pattern, and the maximum width W and the pitch P are set to the same value.

As a method of moving the substrate stage 12 and the mask stage 17, besides the above-mentioned method of fixing the electron gun 13 and moving the substrate stage 12 and the mask stage 17 in the same direction (in-phase method), , Substrate stage 1
A method of moving the mask stage 17 and the mask stage 17 in directions different from each other, that is, in a reverse direction in which one is the Y direction and the other is the −Y direction (a different phase method) may be adopted. When the different phase method is adopted, the configuration of the deflecting / reducing lens 14C is configured to invert the image as in the case of light. In this manner, as can be seen from FIG. 1, in the in-phase method, when the substrate stage 12 and the mask stage 17 are moved in the same direction, the center of gravity of the apparatus moves greatly, so that the apparatus tends to be unstable during operation. However, in the heterophase system, such a fear is eliminated, and the apparatus is stabilized even during operation.

How to synchronize the movement of the substrate stage 12 and the mask stage 17 depends on the design magnification of the circuit pattern 16a on the mask 16. That is,
For example, when using a circuit pattern 16a having a design magnification of four times, the mask stage 17 may be moved at a speed four times the speed of the substrate stage 12 irrespective of the in-phase system or the out-of-phase system.

In the present embodiment, the irradiation is performed so that the pitch P is smaller than the maximum width W, so that the side of the partial irradiation area 22 is double-irradiated.
To form Dual irradiation section 22 in partial irradiation area 22
The portion other than a is referred to as a non-dual irradiation unit 22b for convenience. Here, the dimensional difference between the maximum width W and the pitch P is 10 μm or less, and therefore, the width of the double irradiation part 22a is 10 μm or less.

Further, in the present embodiment, the partial irradiation region 22
Irradiation amount of the double irradiation unit 22a and the non-double irradiation unit 22b,
That is, the total dose of the circuit pattern 16a is equal. In order to realize this, as shown in FIG. 3, the aperture ratio of the region where the width of both sides is P / 2 ± d is approximately 5%.
A half of each of the regions is masked so as to be 0%, and a forming aperture 15A having an opening pattern 15a having an opening area of about 1 mm ² is used.

FIG. 4A shows the forming aperture 1 shown in FIG.
The X-direction distribution of the total dose when the electron beam passing through 5A passes through the circuit pattern 16a is shown.
As shown in FIG. 4A, the double irradiation unit 22a shown in FIG.
X = -P / 2 ± d and X = P / 2 ± d corresponding to
The dose amount of the region is half that of the region corresponding to the non-dual irradiation part 22b shown in FIG. FIG.
4B shows the dose distribution when the dose distribution shown in FIG. 4A is shifted by the pitch P in the X direction.
As shown in FIG. 4B, the height when all the dose distributions are added, that is, the partial irradiation area 22 shown in FIG.
Is performed, the total dose is equal to the predetermined amount of 1. The distribution of the total dose in the X direction is symmetric with respect to the Y axis.

Hereinafter, a case where irradiation is performed using the shaping aperture 15A shown in FIG. 3 will be considered. When the irradiation is performed while moving the mask 16 and the semiconductor substrate 11 by the pitch P, if the moving amount of the pitch P always coincides with the predetermined amount, the double irradiation portions 22a with the dose amount of ２ surely overlap each other. Therefore, the entire circuit pattern 16a is irradiated with a predetermined dose.

Here, it is assumed that the pitch P slightly fluctuates from a predetermined amount P to P + q including a pitch error q (q is positive). The fluctuation factor occurs, for example, as a detection error when detecting the position of the substrate stage 12 or the like. When the forming aperture 15A according to the present embodiment is used, FIG.
As shown in (a), a region where the total dose changes occurs, but as long as q <(WP) / 2, the decrease is at most a half and the dose is 2 Although the dimension is reduced in the region of 1 / min, no disconnection occurs. In addition, if the opening pattern of the forming aperture is square as in the related art, a region where the total dose is 0 occurs as shown in FIG. 5B, so that when a negative resist is used, If a circuit pattern exists in a region where the total dose is 0, disconnection occurs.

In the present embodiment, if the pitch error q is sufficiently small, almost no dimensional fluctuation occurs.
Similarly, when the pitch error q is negative, the forming aperture 15
By using A, X =
Since the dose amount in the region of −P / 2 ± d and the region of X = P / 2 ± d is の of that in the region corresponding to the non-dual irradiation part 22b, dimensional fluctuation and pattern deformation are prevented. It is unlikely to occur. Here, the forming aperture 15A for halving the irradiation amount
It is needless to say that the area 2d on both sides of the area is larger than the expected pitch error q (connection error).

Further, as shown in FIG.
Opening pattern 1 in which the opening ratio of the area of ± 2 ± d is approximately 50%
A shaping aperture 15B having 5a may be used.

(First Modification of First Embodiment) A first modification of the first embodiment according to the present invention will be described below with reference to the drawings.

FIG. 7 shows a plan configuration of a forming aperture used in the charged particle writing apparatus according to the present modification. As shown in FIG. 7, the forming aperture 15C has a trapezoidal opening pattern 15a, and the maximum width W of the opening pattern 15a.
Assuming that the pitch, which is the amount of repetitive movement, is P, the lower base of the trapezoid is W, and the upper base is L = 2P−W.

FIG. 8A shows the forming aperture 1 shown in FIG.
The distribution in the X direction of the total dose when the electron beam passing through 5C passes through the circuit pattern 16a is shown.
As shown in FIG. 8A, the dose amount becomes a predetermined amount of 1 in the region of -L / 2 ≦ X ≦ L / 2, and 0.5 when X = ± P / 2 and 0.5 when X = ± W / 2. The dose changes linearly and continuously so as to become zero.

Hereinafter, the case where irradiation is performed using the shaping aperture 15C shown in FIG. 7 will be considered. When the irradiation is performed while moving the mask 16 and the semiconductor substrate 11 by the pitch P, if the moving amount of the pitch P always coincides with the predetermined amount, FIG.
As shown in (b), the entire circuit pattern 16a is irradiated with a predetermined dose. Therefore, the lower base W is larger than the upper base L, for example, the forming aperture 15.
By using C, a part of the circuit pattern 16a can be double-irradiated. Here, the forming aperture 1 shown in FIG.
5C, the difference between the lower base W and the upper base L is 10 μm or less, that is, FIG.
The width of the area corresponding to the double irradiation part 22a shown in FIG.
It is as follows.

As apparent from FIG. 8B, the pitch P
If the moving amount of the double irradiation unit 22a always coincides with the predetermined amount, the sum of the dose amounts of the double irradiation unit 22a shown in FIG. 2 is always 1, so that the entire pattern of the circuit pattern 16a is irradiated with the same dose amount. .

Here, it is assumed that the pitch P slightly changes from a predetermined amount P to P + q including a pitch error q (q> 0). When the forming aperture 15C according to the present modification is used,
As shown in FIG. 5A, a region where the total dose changes occurs, but the dose reduction amount is q / (WP).
This indicates that the amount of dose reduction becomes で when q = (WP) / 2. If q <(WP) / 2, the dose reduction amount is less than 1/2, and the circuit pattern 16
a has almost no effect on the pattern deformation. In addition,
As shown in FIG. 9B, if the opening pattern of the shaping aperture is square as in the related art, a region where the total dose is 0 occurs, and therefore, when a negative resist is used, the entire dose is reduced. If a circuit pattern exists in a region where the amount is 0, disconnection occurs.

Similarly, when the pitch error q is negative, since the dose amount is 0.5 at X = ± P / 2 in the partial irradiation area 22 by using the shaping aperture 15C, the dimensional variation and the pattern Deformation is less likely to occur. here,
It goes without saying that the area 2d on both sides of the shaping aperture 15C has a value larger than the expected pitch error q (connection error).

As shown in FIG. 10A, the opening pattern 15a may be a parallelogram shaped aperture 15D, and as shown in FIG.
5a may be a hexagonal shaped aperture 15E.

(Second Modification of First Embodiment) A second modification of the first embodiment according to the present invention will be described below with reference to the drawings.

FIG. 11A shows a plan configuration of a forming aperture used in the charged particle drawing apparatus according to the present modification. As shown in FIG. 11A, a shaping aperture 15F having a rectangular opening pattern 15a has an opening 15b having a width L and a transmittance of 100% for an electron beam, a maximum width W of the opening pattern 15a and an opening 15b. The opening peripheral portion 15c in which the transmittance of the electron beam in the region between the widths L is approximately 50%. Here, the transmittance of the electron beam in the region outside the opening peripheral portion 15c in the forming aperture 15F is almost 0%.
Needless to say, Further, the pitch P, the maximum width W, and the opening width L, which are the amount of repetition, are P = (L +
W) / 2. In addition, the dimensional difference between the maximum width W and the pitch P is 10 μm or less.
The width of the double irradiation part 22a shown in FIG.

FIG. 12A shows that the electron beam having passed through the shaping aperture 15F shown in FIG.
6A shows the distribution of the total dose in the X direction when the light passes through 6a. As shown in FIG. 12A, if the dose of the opening 15b is 1, the dose is 1 / X = ± P / 2.
Obviously, the width of the region where the dose amount is not 1 is 2d = (WL) / 2. At this time, -W / 2
In the region of <X <-L / 2 and the region of L / 2 <X <W / 2, the dose amount is １ ／ of the region corresponding to the opening 15b.

FIG. 12B shows the dose distribution when the dose distribution shown in FIG. 12A is shifted by the pitch P in the X direction. As shown in FIG. 12B, the height when all the dose distributions are added, that is, the total dose becomes a predetermined amount of 1. The distribution of the total dose in the X direction is symmetric with respect to the Y axis.

Hereinafter, the forming aperture 15F shown in FIG.
Let us consider the case where irradiation is performed using. When the irradiation is performed while moving the mask 16 and the semiconductor substrate 11 by the pitch P, if the moving amount of the pitch P always coincides with the predetermined amount, a region corresponding to the opening peripheral portion 15 c having a dose of ２, that is, The double irradiation portions 22a shown in FIG. 2 surely overlap each other, and the sum of the dose amounts of the double irradiation portions 22a is always 1, so that the entire circuit pattern 16a is irradiated with a predetermined dose amount.

Here, it is assumed that the pitch P slightly changes from a predetermined amount P to P + q including a pitch error q (q> 0). By using the forming aperture 15F according to this modification,
As shown in FIG. 13 (a), a region where the total dose changes occurs, but the amount of decrease is at most one half, and in the region where the dose is one half, the dimension becomes thin. However, it does not lead to disconnection. If the opening pattern of the forming aperture is square as in the prior art, FIG.
As shown in (b), since a region where the total dose is 0 occurs, disconnection occurs when a negative resist is used and a circuit pattern exists in a region where the total dose is 0.

In this modification, the pitch error q
Is sufficiently small, there is almost no dimensional change. Similarly, when the pitch error q is negative, X = −P in the partial irradiation region 22 is obtained by using the shaping aperture 15F.
The dose in the region of / 2 ± d and the region of X = P / 2 ± d is 2 in the region corresponding to the non-dual irradiation part 22b shown in FIG.
Since it is one-half, dimensional fluctuation and pattern deformation hardly occur. Here, the area 2d on both sides of the shaping aperture 15F for halving the irradiation amount is the expected pitch error q
Needless to say, a value larger than (connection error) is used.

Note that the forming aperture 15 according to this modification is
F has an opening peripheral portion 15c at the periphery of the opening pattern 15a where the transmittance of the electron beam is 50%, so that not only the method of scanning (scanning) the beam but also the stopping of the mask 16 and the semiconductor substrate 11 for a predetermined time. It can also respond to the step-and-repeat method of irradiating. In this case, the mask 16 and the semiconductor substrate 11 are formed so that the upper and lower ends of the opening peripheral portion 15c are also double-irradiated.
Need to be moved.

(Third Modification of First Embodiment) A third modification of the first embodiment according to the present invention will be described below with reference to the drawings.

FIG. 11B shows a plan configuration of a forming aperture used in the charged particle drawing apparatus according to the present modification. As shown in FIG. 11B, a forming aperture 15G having a square opening pattern 15a has an opening 15b having a width L and a transmittance of 100% for an electron beam, a maximum width W of the opening pattern 15a and an opening. An opening edge portion 15c in which the transmittance of the electron beam in the region between the widths L is approximately 50%, and an opening corner portion 15d in which the transmittance of the electron beam at the four corners of the opening edge portion 15c is approximately 25%. I have. Here, the transmittance of the electron beam in the region outside the opening peripheral portion 15c and the opening corner 15d in the forming aperture 15G is almost 0%.
Needless to say, In this way, when the step-and-repeat method is used, the total dose can be reliably set to one.

In the second and third modified examples, the opening peripheral portions 15c and 25c having an electron beam transmittance of 50% are used.
%, A thin film made of silicon nitride (SiN) is used as the opening corner 15d, and the transmittance of the electron beam is almost 0%.
A sufficiently thick silicon (Si) is used for the aperture main body.

The forming aperture 1 according to the second modified example
If 5F is used only for the scanning method, the width is 2d.
The region where the electron beam transmittance is 50%
a may be formed only on both sides.

(Second Embodiment) Hereinafter, a second embodiment according to the present invention will be described with reference to the drawings.

FIG. 14 schematically shows the front configuration of a charged particle writing apparatus according to the second embodiment of the present invention. In FIG. 14, the same components as those shown in FIG. In the first embodiment, in order to make the irradiation amount of the electron beam to the double irradiation portion in the irradiation region to be half of the irradiation amount of the non-double irradiation portion, the shape of the peripheral portion of the opening pattern in the forming aperture is changed. Although it has a feature, in this embodiment,
The electron gun, which is a charged particle generating means, has its characteristics. Therefore, as shown in FIG. 14, no forming aperture is provided between the electron gun 31 and the mask 16 according to the present embodiment.

FIG. 15A shows an electron gun 3 according to this embodiment.
FIG. 15 shows a partial configuration of a charged particle generation source 40 in which a plurality of field emission electron sources used in 1 are arranged in an array.
(B) shows a cross-sectional configuration taken along line II of (a). The charged particle generation source 40 shown in FIGS.
Has a plurality of field emission electron sources 41 arranged on a substrate as disclosed in, for example, Japanese Patent Application Laid-Open No. 9-27266. The field emission type electron source 41 includes a cone-shaped cathode 42a formed on a substrate 42 made of conductive silicon.
And a lead electrode 44 made of a metal film and having an opening at the periphery of the tip of each cathode 42a via an insulating film 43 made of silicon oxide. Cathode 42a
And a positive voltage is applied to the extraction electrode 44 to extract electrons from the cathode 42a. The amount of electrons to be extracted can be controlled by the voltage value of the extraction electrode 44.
Although not shown, an anode for accelerating the extracted electrons is provided on the side facing the cathode 42a.

FIG. 16A shows a simplified plan configuration of the charged particle generation source according to the present embodiment. FIG.
As shown in (a), the charged particle generation source 40A has 4 rows ×
It has 200 field emission electron sources 41 arranged in an array of 50 columns. As a feature of the present embodiment, 50
Of the field emission electron sources 41 in the row, 3
Each row is assumed to be about 50% of the output value of the field emission type electron source 41 for the central 44 rows.

In this way, three rows on both sides are made to correspond to the double irradiation part 22a of the partial irradiation area 22 shown in FIG.
In addition, the partial irradiation area 22 shown in FIG.
When the electron beam is scanned so as to correspond to the non-dual irradiation part 22b, as shown in FIG.
The dose amount of 2a and the non-dual irradiation part 22b, that is, the total dose amount is substantially the same.

(First Modification of Second Embodiment) FIG. 16
In the charged particle generation source 40A shown in (a), of the 50 rows of the field emission electron sources 41, the output values of each of the 3 rows located on both sides are approximately 25% in order from the outside to the inside,
Stepwise change to about 50%, about 75%. Here, the output value of the 44 columns at the center is 100%. In this case, as shown in FIG. 16C, the doses of the double irradiation section 22a and the non-double irradiation section 22b become substantially the same.

(Second Modification of Second Embodiment) FIG. 17
(A) shows a simplified planar configuration of the charged particle generation source according to this modification. As shown in FIG. 17A, the charged particle generation source 40B has 184 field emission electron sources 41 arranged in an array of 4 rows × 46 columns at the center, and both sides of the center and There are eight field emission electron sources 41 in a total of 2 rows × 2 columns along one side of the array. As a result, the number of field emission electron sources 41 in the two rows on both sides is reduced by half as compared with the center, and the substantial output value on both sides is reduced by half compared to the center. Therefore, each of the two rows on both sides is made to correspond to the double irradiation part 22a of the partial irradiation area 22 shown in FIG. 2, and the 46 rows of the central part are used for the non-double irradiation of the partial irradiation area 22 shown in FIG. When the electron beam is scanned so as to correspond to the portion 22b, as shown in FIG. 17B, the doses of the double irradiation portion 22a and the non-double irradiation portion 22b, that is, the total doses are substantially the same. Becomes

(Third Modification of Second Embodiment) FIG. 18
(A) shows a simplified planar configuration of the charged particle generation source according to this modification. As shown in FIG. 18A, the charged particle generation source 40C has 156 field emission electron sources 41 arranged in an array of 4 rows × 44 columns at the center, and 3 of the electron emission sources 41 on both sides of the center. The number gradually decreases to 3, 2, and 1 as the row portion goes along one side of the array and goes outward.
It has two field emission electron sources 41. Thus, the number of the field emission electron sources 41 in the three rows on both sides is gradually reduced as compared with the center. Therefore, three rows on both sides correspond to the double irradiation part 22a of the partial irradiation area 22 shown in FIG. 2, and 44 rows at the center part correspond to the non-double irradiation of the partial irradiation area 22 shown in FIG. When the electron beam is scanned so as to correspond to the portion 22b, as shown in FIG. 18B, the dose of the double irradiation portion 22a and the non-double irradiation portion 22b, that is, the total dose is substantially the same. Becomes

In the first and second embodiments, an electron beam is used for the charged particles, but the same effect can be obtained by using an ion beam.

[0074]

According to the charged particle writing method and the charged particle writing apparatus of the present invention, disconnection or deformation of a resist pattern due to a connection error when repeating partial irradiation can be prevented, and the performance and yield of a semiconductor device can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a charged particle drawing apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of the mask for describing a writing method on the mask in the charged particle writing apparatus according to the first embodiment of the present invention.

FIG. 3 is a plan view of a forming aperture in the charged particle writing apparatus according to the first embodiment of the present invention.

FIG. 4A is a graph showing a dose distribution of an electron beam passing through a shaping aperture in the charged particle writing apparatus according to the first embodiment of the present invention. 6B is a graph illustrating a dose distribution when the charged particle writing apparatus according to the first embodiment of the present invention irradiates the electron beam through the shaping aperture while overlapping.

FIG. 5A is a graph illustrating a dose distribution when a connection error occurs when the charged particle lithography apparatus according to the first embodiment of the present invention irradiates an electron beam through a shaping aperture while overlapping the electron beam; It is. (B) is a graph showing a dose distribution when a connection error occurs in an electron beam passing through a conventional shaping aperture.

FIG. 6 is a plan view of a forming aperture in the charged particle writing apparatus according to the first embodiment of the present invention.

FIG. 7 is a plan view of a forming aperture in a charged particle writing apparatus according to a first modification of the first embodiment of the present invention.

FIG. 8A is a graph showing a dose distribution of an electron beam passing through a shaping aperture in a charged particle writing apparatus according to a first modification of the first embodiment of the present invention.
(B) is a graph showing a dose distribution when an electron beam passing through a shaping aperture is irradiated while overlapping with each other in the charged particle writing apparatus according to the first modification of the first embodiment of the present invention.

FIG. 9A shows a dose when a connection error occurs when the charged particle lithography apparatus according to the first modification of the first embodiment of the present invention irradiates an electron beam passing through a shaping aperture while superimposing it. It is a graph which shows a quantity distribution. (B) is a graph showing a dose distribution when a connection error occurs in an electron beam passing through a conventional shaping aperture.

FIGS. 10A and 10B are plan views of a forming aperture in a charged particle writing apparatus according to a first modification of the first embodiment of the present invention.

FIG. 11A is a plan view of a forming aperture in a charged particle writing apparatus according to a second modification of the first embodiment of the present invention. (B) is a plan view of a forming aperture in the charged particle writing apparatus according to the third modification of the first embodiment of the present invention.

FIG. 12A is a graph showing a dose distribution of an electron beam passing through a shaping aperture in a charged particle writing apparatus according to a second modification of the first embodiment of the present invention.
(B) is a graph showing a dose distribution when an electron beam passing through a shaping aperture is irradiated while overlapping with each other in a charged particle writing apparatus according to a second modification of the first embodiment of the present invention.

FIG. 13A shows a dose when a connection error occurs when the charged particle lithography apparatus according to the second modification of the first embodiment of the present invention irradiates an electron beam through a shaping aperture while overlapping the electron beam. It is a graph which shows a quantity distribution. (B) is a graph showing a dose distribution when a connection error occurs in an electron beam passing through a conventional shaping aperture.

FIG. 14 is a schematic front view showing a charged particle drawing apparatus according to a second embodiment of the present invention.

FIG. 15A is a partial perspective view showing a charged particle generation source of a charged particle drawing apparatus according to a second embodiment of the present invention, and FIG. 15B is a cross-sectional view taken along line II of FIG. It is.

FIG. 16A is a simplified plan view showing a charged particle generation source of a charged particle drawing apparatus according to a second embodiment of the present invention. (B) is a graph showing a dose distribution when an electron beam from a charged particle generation source is irradiated while being overlapped in the charged particle writing apparatus according to the second embodiment of the present invention. (C) is a graph showing a dose distribution when an electron beam from a charged particle generation source is irradiated while overlapping with each other in a charged particle writing apparatus according to a first modification of the second embodiment of the present invention.

FIG. 17A is a simplified plan view showing a charged particle generation source of a charged particle drawing apparatus according to a second modification of the second embodiment of the present invention. (B) is the second embodiment of the present invention.
9 is a graph showing a dose distribution when an electron beam from a charged particle generation source is irradiated while being overlapped in a charged particle writing apparatus according to a modification.

FIG. 18A is a simplified plan view showing a charged particle generation source of a charged particle drawing apparatus according to a third modification of the second embodiment of the present invention. (B) is the third embodiment of the second embodiment of the present invention.
9 is a graph showing a dose distribution when an electron beam from a charged particle generation source is irradiated while being overlapped in a charged particle writing apparatus according to a modification.

FIG. 19 is a plan view of a mask for describing a writing method on a mask in a conventional electron beam writing apparatus.

FIG. 20 is a plan view of a mask for explaining how a connection error occurs during writing on a mask in a conventional electron beam writing apparatus.

FIG. 21 is a plan view showing the appearance of a resist pattern when a connection error occurs during writing on a mask in a conventional electron beam writing apparatus.

[Explanation of symbols]

 Reference Signs List 11 semiconductor substrate 12 substrate stage 13 electron gun (charged particle generating means) 14A first deflecting lens 14B second deflecting lens 14C deflecting / reducing lens 15 shaping aperture 15A shaping aperture 15B shaping aperture 15C shaping aperture 15D shaping aperture 15E shaping aperture 15F Molding aperture 15G Molding aperture 15a Opening pattern 15b Opening 15c Opening edge 15d Opening corner 16 Mask 16a Circuit pattern (design pattern) 17 Mask stage 21 Molding beam 22 Partial irradiation area 22a Double irradiation part 22b Non-double irradiation part 31 electron gun (charged particle generation means) 40 charged particle generation source 40A charged particle generation source 40B charged particle generation source 40C charged particle generation source 41 field emission type electron source 42 substrate 42a cathode 43 isolation Edge film 44 Leader electrode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/30 541S 541B

Claims (17)

[Claims] A beam forming step of shaping an output beam emitted from a charged particle generation source into a predetermined shape; and transmitting the formed beam to a part of the design pattern of a mask having the design pattern and transmitting the beam. A design pattern transfer step of transferring the design pattern onto the substrate by irradiating a part of the design pattern onto the substrate by irradiating a part of the design pattern with a beam to repeat a partial transfer of the design pattern on the substrate. In the transfer step, when performing the partial transfer, a double irradiation portion is formed in which a part of the irradiation area on the substrate irradiated with the beam is double-irradiated, and the double irradiation section in the irradiation area is formed. Irradiating the irradiation part and the non-dual irradiation part which is not irradiated twice so that the irradiation amount of the beam is substantially the same. Charged particle drawing method to. 2. The beam shaping step includes the step of connecting the output beam to a line segment connecting an end of the dual irradiation section on the non-double irradiation section side and an end of the double irradiation section on the side opposite to the non-double irradiation section. At a midpoint, the method includes a step of forming the irradiation amount of the outgoing beam to be about one half of the irradiation amount of the non-dual irradiation part. 2. The charged particle drawing method according to claim 1, further comprising a step of scanning in a strip shape on the substrate. 3. The method according to claim 1, wherein the irradiation of the output beam in the dual irradiation unit is performed at a dose of 0 at an end opposite to the non-double irradiation unit and the non-double irradiation is performed. A step of continuously changing so as to be a predetermined amount at an end of the part side, wherein the design pattern transfer step includes a step of scanning the formed beam in a band shape on the mask and the substrate. The charged particle drawing method according to claim 1. 4. The beam forming step shapes the outgoing beam so that the irradiation amount of the outgoing beam in the double irradiation unit is about one half of the irradiation amount in the non-double irradiation unit. The step of transferring the design pattern includes irradiating a beam formed on a part of the mask and the substrate on the substrate in a stopped state, and thereafter, irradiating the beam with an end portion of the irradiated area on the moving direction side of the beam. 2. The charged particle writing method according to claim 1, further comprising the step of moving the object so as to irradiate the object in a double manner. 5. The method according to claim 5, wherein the beam shaping step comprises: changing the output beam at four corners of the irradiation area so that the irradiation amount of the irradiation beam of the double irradiation unit is about one fourth of the irradiation amount of the non-double irradiation unit. The charged particle drawing method according to claim 4, further comprising a step of forming the charged particle. 6. The charged particle drawing according to claim 1, wherein a width of the double irradiation unit is smaller than about one hundredth of a movement width of the irradiation area when the partial transfer is repeated. Method. 7. The charged particle writing method according to claim 1, wherein the width of the double irradiation part is smaller than about one hundredth of the width of the irradiation area. 8. A method of irradiating a portion of the design pattern of a mask having a design pattern on a substrate by using a beam of charged particles, and repeating the irradiation while overlapping a part of the portion, thereby forming a mask on the substrate. A charged particle drawing apparatus that draws the design pattern on the charged particle generating means that emits the beam toward the substrate; a substrate holding means that holds the substrate; and the charged particle generating means that includes the mask. A mask holding means for holding between the substrate and the mask; a shaping aperture provided between the charged particle generating means and the mask held by the mask holding means for shaping the beam into a predetermined shape; Means and a moving means for relatively moving the substrate holding means and the charged particle generating means, wherein the shaping aperture is provided on the substrate. When forming a double-irradiated portion that is double-irradiated and a non-double-irradiated portion that is not double-irradiated in an irradiation region that is irradiated with a beam that passes through the mask, the double-irradiated portion and the non-double-irradiated portion are not irradiated. A charged particle lithography apparatus having an opening pattern such that the irradiation amount of the beam with a double irradiation unit is substantially the same. 9. An opening ratio of a region corresponding to the double irradiation portion in the opening pattern is approximately 50%, and an opening ratio of a region corresponding to the non-double irradiation portion in the opening pattern is approximately 100%. 9. The method according to claim 8, wherein
2. The charged particle drawing apparatus according to 1. 10. The opening pattern has a parallelogram shape in which sides of a region corresponding to the double irradiation portion in the opening pattern are oblique sides facing each other. 2. The charged particle drawing apparatus according to 1. 11. The opening pattern according to claim 9, wherein the opening pattern has a trapezoidal shape in which sides of a region corresponding to the double irradiation section are oblique sides facing each other. The charged particle drawing apparatus according to the above. 12. The transmittance of a region of the opening pattern corresponding to the double irradiation portion is approximately 50%, and the transmittance of a region of the opening pattern corresponding to the non-double irradiation portion is approximately 100%. The charged particle drawing apparatus according to claim 8, wherein: 13. The mask holding means is a mask stage, the substrate holding means is a substrate stage, and the moving means moves the mask stage and the substrate stage while synchronizing with each other. A charged particle drawing apparatus according to claim 8. 14. A method of irradiating a portion of the design pattern of a mask having a design pattern on a substrate by using a beam of charged particles, and repeating the irradiation while overlapping the portion, thereby forming a mask on the substrate. A charged particle drawing apparatus that draws the design pattern on the charged particle generating means that emits the beam toward the substrate; a substrate holding means that holds the substrate; and the charged particle generating means that includes the mask. A mask holding unit that holds the substrate between the substrate and the substrate; and a moving unit that relatively moves the mask holding unit, the substrate holding unit, and the charged particle generation unit, wherein the charged particle generation unit is provided on the substrate. In the irradiation area irradiated with the beam transmitted through the mask in (2), a double irradiation part that is double irradiated and a non-double irradiation part that is not double irradiated are formed. In this case, the dual irradiation unit and the non-double irradiation unit have a plurality of charged particle generation sources having an arrangement such that the irradiation amount of the beam is substantially the same. Charged particle drawing equipment. 15. The charged particle generation source in the region corresponding to the double irradiation part in the charged particle generation means emits charged particles in comparison with the charged particle generation source in the region corresponding to the non-double irradiation part. 15. The charged particle writing apparatus according to claim 14, wherein energy is approximately 50%. 16. The number of charged particle generation sources in a region corresponding to the double irradiation section in the charged particle generation means in the direction of movement of the beam in the area corresponding to the double irradiation section is the number of charged particle generation sources in the area corresponding to the non-double irradiation section. 15. The charged particle drawing apparatus according to claim 14, wherein the number is approximately one half of the number. 17. The method according to claim 17, wherein the mask holding unit is a mask stage, the substrate holding unit is a substrate stage, and the moving unit moves the mask stage and the substrate stage while synchronizing with each other. The charged particle drawing apparatus according to claim 14.