JP4401116B2 - Electron beam exposure method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention,Concerning the electron beam exposure method, in particular, sequential exposure is performed for each pattern to be exposed.RudenThe present invention relates to a sub-line exposure method.
[0002]
[Prior art]
In the electron beam sequential exposure method, the deflector is controlled so that the electron beam enters a desired position, and the electron beam is actually irradiated after the deflection control waiting time has elapsed. The deflection control waiting time is set based on the time until the incident position of the electron beam is stabilized on the wafer with an accuracy of an allowable error or less.
[0003]
The electron beam exposure method generally has a higher resolution than the light exposure method. However, as the density of semiconductor integrated circuit devices increases, the number of patterns to be exposed increases. For each of these patterns, it is necessary to wait for the electron beam irradiation for the deflection control waiting time from the start of the control of the deflector to the actual exposure. For this reason, the time required for exposing all the patterns becomes longer, and the throughput is lowered.
[0004]
Patent Document 1 discloses an electron beam exposure method capable of suppressing a decrease in throughput. According to this method, at the time of exposure of a pattern that does not require relatively high accuracy, the processing speed is increased by shortening the deflection control waiting time.
[0005]
[Patent Document 1]
JP 54-25675 A
[0006]
[Problems to be solved by the invention]
Patent Document 1 does not describe a specific method for shortening the deflection control waiting time.
[0008]
  The present inventionEyesThe objective is to provide an electron beam exposure method capable of increasing the processing speed.
[0011]
[Means for Solving the Problems]
  Of the present inventiononeAccording to perspective
  (A) A plurality of upper deflection fields are defined on the surface of the wafer to be exposed, and a plurality of lower deflection fields smaller than the upper deflection field are defined inside each of the upper deflection fields, A plurality of patterns to be exposed are defined in each of the plurality of patterns, and the plurality of patterns are classified into at least two first sections and second sections according to required position accuracy, and belong to the first section. Preparing a wafer that requires a higher positional accuracy than a pattern belonging to the second section in a pattern; and
  (B) exposing a pattern to be exposed in one lower deflection field of the wafer by scanning an electron beam with a lower deflector;
  (C) controlling the upper deflector so that an electron beam can be irradiated in the lower deflection field that is not exposed;
  (D) exposing a pattern belonging to the second section in the lower deflection field in which the electron beam irradiation is enabled in the step (c);
  (E) exposing a pattern belonging to the first section in the lower deflection field after exposure of the pattern belonging to the second section;
An electron beam exposure method is provided.
  According to another aspect of the invention,
  A plurality of upper deflection fields are defined on the surface of the wafer to be exposed, and a plurality of lower deflection fields smaller than the upper deflection fields are defined within each of the upper deflection fields, and each of the lower deflection fields is defined. Providing the wafer internally defining a plurality of patterns to be exposed;
  Dividing one pattern to be exposed on the wafer into a plurality of first sub-patterns in contact with the outer periphery of the pattern and at least one second sub-pattern not in contact with the outer periphery; Dividing each of the first sub-pattern and the second sub-pattern into first and second sub-patterns irradiated with an electron beam without scanning the electron beam;
  Controlling the upper deflector so that it can be irradiated with an electron beam in the lower deflection field to be exposed next;
  Exposing the second sub-pattern in the lower deflection field enabled to be irradiated with an electron beam;
  Exposing the first sub-pattern in the lower deflection field after exposure of the second sub-pattern in the lower deflection field enabled to be irradiated with an electron beam;
An electron beam exposure method is provided.
[0012]
  Immediately after controlling the upper deflector, a pattern that does not require high positional accuracy is exposed, so the deflection control waiting time can be shortened..
[0013]
According to another aspect of the invention,
  A step of creating design data having a pattern identification field for specifying a pattern of each layer of a semiconductor integrated circuit device and a layer information field for defining a layer on which the pattern is arranged,Of the patterns in the same layer,The value of the layer information field is different between the pattern where the tolerance of misalignment is larger than the reference value and the pattern where it is smaller than the reference value.In the layer information field, the first value and the second value are set, respectively.The process of creating design data;
  A step of creating exposure data in a format that can be input to an electron beam exposure apparatus based on the design data, the exposure data including information defining a deflection control waiting time for each pattern to be exposed; A step of setting information for defining the deflection control waiting time based on the value of the layer information field of the design data;
  Based on the exposure dataThe pattern in which the first value and the second value are set in the layer information field is transferred to the same layer.A process of exposing the wafer;
HaveAnd
  A plurality of upper deflection fields are defined on the surface of the wafer, and a plurality of lower deflection fields smaller than the upper deflection field are defined within each of the upper deflection fields, and each of the lower deflection fields is disposed within each of the upper deflection fields. A plurality of patterns to be exposed are defined, the plurality of patterns are classified into at least two first sections and second sections, and the deflection control waiting time of the patterns belonging to the first section is Longer than the deflection control waiting time of the pattern belonging to the second section,
  The step of exposing the wafer comprises:
  Controlling the upper deflector so that it can be irradiated with an electron beam in the lower deflection field to be exposed next;
  Exposing a pattern belonging to the second section in the lower deflection field enabled to be irradiated with an electron beam;
  Exposing the pattern belonging to the first section in the lower deflection field after exposure of the pattern belonging to the second section;
includingAn electron beam exposure method is provided.
[0014]
Information specifying the deflection control waiting time is stored in the layer information field of the design data. For this reason, it is not necessary to add a new field for designating the deflection control waiting time to the design data.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic diagram of an electron beam exposure apparatus according to an embodiment of the present invention. The electron gun 1 emits an electron beam. The stage 9 holds the wafer 20 on its upper surface. The electron beam emitted from the electron gun 1 is incident on the wafer 20 held on the stage 9. Along the electron beam path from the electron gun 1 to the stage 9, the first slit 2, the slit deflector 3, the second slit 4, the blanking 5, the aperture 6, the sub deflector 7, and the main deflector 8. Are arranged in this order. Note that a plurality of lenses 15 for focusing the electron beam are disposed as necessary.
[0016]
An electron beam emitted from the electron gun 1 enters the first slit 2. The first slit 2 shapes the cross section of the electron beam into a square. The traveling direction of the electron beam that has passed through the first slit 2 is changed by the slit deflector 3. An electron beam whose traveling direction is swung by the slit deflector 3 enters the second slit 4. The square opening of the first slit 2 forms an image at the position of the second slit 4.
[0017]
A square opening is formed in the second slit 4. An electron beam that has entered the opening passes through the second slit 4. The electron beam incident outside the opening is shielded by the second slit 4.
[0018]
The blanking 5 changes the traveling direction of the electron beam that has passed through the second slit 4. An opening through which an electron beam passes is formed at the center of the aperture 6. When the electron beam goes straight through the blanking 5, it passes through the opening at the center of the aperture 6. When the traveling direction of the electron beam is changed by blanking 5, the electron beam is shielded by the aperture 6. That is, the blanking 5 and the aperture 6 constitute an electron beam shutter.
[0019]
The electron beam that has passed through the aperture 6 is subjected to deflection control by the sub deflector 7 and further subjected to deflection control by the main deflector 8. The deflection-controlled electron beam is incident on a desired position of the wafer 20 held on the stage 9. A rectangular pattern corresponding to an overlapping portion between the image of the opening of the first slit 2 formed at the position of the second slit 4 and the opening of the second slit 4 is transferred to the wafer 20. By changing the traveling direction of the electron beam by the slit deflector 3, the length of the long side and the short side of the rectangular pattern transferred to the wafer 20 can be changed. The control device 10 controls the blanking 5, the sub deflector 7, and the main deflector 8.
[0020]
Next, the electron beam exposure method according to the first embodiment will be described with reference to FIG.
FIG. 2A shows a pattern to be exposed defined on the surface of the wafer. A plurality of dummy patterns A and B to J are arranged in the area 25, and device patterns K to N are arranged in the area 26. The dummy patterns A to J do not function as an electronic circuit, and are used for the purpose of making the etching rate uniform during etching and improving the flatness during chemical mechanical polishing (CMP). For this reason, the dummy patterns A to J do not require high positional accuracy, and the allowable positional deviation is, for example, about 50 nm. The permissible positional deviation value of the device patterns K to N is, for example, about 5 nm.
[0021]
FIG. 2B shows a part of the format of the exposure data given to the electron beam exposure apparatus. The exposure data has a pattern identification field and a waiting time field. A value for specifying a pattern to be exposed is stored in the pattern identification field. A waiting time field is secured corresponding to each storage area of the pattern identification field. The waiting time field stores a value for specifying a deflection control waiting time when the pattern is exposed. The exposure data includes information such as pattern dimensions, main deflection position, sub-deflection position, and exposure amount.
[0022]
Hereinafter, the deflection control waiting time will be briefly described. When the exposure of one pattern is completed, the sub deflector of the electron beam exposure apparatus is controlled to move the incident position of the electron beam to the position of the pattern to be exposed next. However, there is a delay until the incident position of the electron beam moves to the desired position, and even after reaching the desired position, it takes time for the incident position to vibrate and stabilize. The time until the deviation of the incident position of the electron beam falls within a predetermined allowable error range is called a deflection control waiting time.
[0023]
FIG. 3 shows an example of the deflection stabilization characteristics of the sub deflector. The horizontal axis represents the elapsed time from the completion of exposure of one pattern in the unit “ns”, and the vertical axis represents the deflection deviation (deviation amount from the desired position to the actual electron beam incident position) in the unit “nm”. ".
[0024]
The allowable displacement of the dummy patterns A to J is 50 nm. When the elapsed time exceeds 60 ns, the deflection deviation becomes 50 nm or less. For this reason, when the dummy patterns A to J are exposed, the deflection control waiting time may be set to 60 ns. The device pattern K to N is allowed to have a positional deviation of 5 nm. When the elapsed time exceeds 500 ns, the deflection deviation becomes 5 nm or less. For this reason, when the device patterns K to N are exposed, the deflection control waiting time may be set to 500 ns.
[0025]
As shown in FIG. 2B, a value “ST” indicating that the waiting time is 60 ns is stored in the waiting time field corresponding to the dummy patterns A to J. A value “LG” indicating that the waiting time is 5 ns is stored in the waiting time field corresponding to the device patterns K to N.
[0026]
The control apparatus 10 shown in FIG. 1 sets the deflection control waiting time to a short time corresponding to the value “ST” when exposing the dummy patterns A to J based on the exposure data shown in FIG. When the device patterns K to N are exposed to 60 ns, the deflection control waiting time is set to a long time corresponding to the value “LG”, for example, 500 ns.
[0027]
According to the first embodiment, the deflection control waiting time when the dummy patterns A to J are exposed is shorter than the deflection control waiting time when the device patterns K to N are exposed. For this reason, the processing time can be shortened compared with the case where the deflection control waiting time of all patterns is set to the deflection control waiting time when the device patterns K to N are exposed.
[0028]
An electron beam exposure method according to the second embodiment will be described with reference to FIG. A general electron beam exposure apparatus is provided with a pattern shot division function that divides one pattern to be exposed into a plurality of exposure unit patterns and irradiates an electron beam for each exposure unit pattern. In the second embodiment, the deflection control waiting time is controlled using this pattern shot division function.
[0029]
FIG. 4A shows an example of a pattern to be exposed. A rectangular pattern A having a short side of 4 μm and a long side of 8 μm, a linear pattern B having a length of 8 μm and a width of 0.5 μm, and a square dummy pattern C having a side of 3.5 μm are defined. The positional deviation allowable error of the dummy pattern C is larger than the allowable errors of the other device patterns A and B.
[0030]
FIG. 4B shows an exposure unit pattern when exposure is performed using the pattern shot division function. A relatively large pattern such as pattern A is divided into small exposure unit patterns A1 to A8 by applying a division rule with a maximum dimension of 2 μm in order to suppress image blur due to the Coulomb effect. Each exposure unit pattern A1 to A8 is a square having a side length of 2 μm.
[0031]
Like pattern B, a long pattern exceeding the maximum dimension that can be exposed in one shot is divided into exposure unit patterns B1 and B2 having a length of 4 μm by applying a division rule that sets the maximum dimension to 4 μm. The dummy pattern C is not divided and is exposed in one shot.
[0032]
FIG. 4C shows a part of the exposure data input to the electron beam exposure apparatus. The exposure data includes a pattern identification field in which a value for specifying a pattern to be exposed is stored, and a division rule field provided for each pattern to be exposed. The division rule field stores a value that defines the division rule of the pattern. For example, a division rule that sets the maximum dimension to 2 μm is “1”, and a division rule that sets the maximum dimension to 4 μm is “2”. In this case, the division rule “1” is stored in the division rule field of the pattern A, and the division rule “2” is stored in the division rule field of the pattern B.
[0033]
The division rule “9” is stored in the division rule field of pattern C. In the second embodiment, the division rule “9” not only means that exposure is performed in one shot without division, but also means that the deflection control waiting time is long.
[0034]
FIG. 4D shows a correspondence relationship between the division rule and the deflection control waiting time. The division rules “1” and “2” correspond to the long deflection control waiting time “LG”, and the division rule “9” corresponds to the short deflection control waiting time “ST”. This correspondence is stored in advance in the control device 10 of the electron beam exposure apparatus shown in FIG. For other division rules, the correspondence between the division rule and the deflection control waiting time is stored.
[0035]
When the dummy pattern C is exposed, the control device 10 of the electron beam exposure apparatus shown in FIG. 1 reads from the exposure data that the division rule is “9”. When the division rule is “9”, the control device 10 performs exposure of the dummy pattern C by shortening the deflection control waiting time.
[0036]
In the second embodiment, the deflection control waiting time is specified by setting a specific value (“9” in the above embodiment) in the division rule field. That is, information related to the deflection control waiting time associated with each pattern is stored in the division rule field of the exposure data. For this reason, it is possible to associate information on the deflection control waiting time for each pattern without adding a new field to the exposure data.
[0037]
Next, an electron beam exposure method according to the third embodiment will be described with reference to FIGS. In the third embodiment, a block exposure (partial batch exposure) method is employed. FIG. 5A shows a schematic diagram of an electron beam block exposure apparatus. A block mask 4 </ b> A is disposed instead of the second slit 4 shown in FIG. 1, and a block selection deflector 3 </ b> A is disposed instead of the slit deflector 3. Between the block mask 4A and the sub deflector 7, a block selective back deflector 30 is disposed. Other configurations are the same as those of the electron beam exposure apparatus shown in FIG.
[0038]
A plurality of blocks 4B are defined in the plane of the block mask 4A. Various shapes of openings are formed in the block 4B. When the block selection deflector 3A changes the traveling direction of the electron beam, a desired one block is selected from the plurality of blocks 4B, and the electron beam passes through the selected block. The pattern of openings formed in the selected block 4B is transferred to the wafer 20.
[0039]
FIG. 5B shows a schematic plan view of the block mask 4A. A plurality of blocks 4B are arranged in the plane. A serial number from 0 to 99 is assigned to each block 4B. One block 4B can be specified by this serial number. In addition to the blocks with serial numbers 0 to 99, variable shaping blocks specified by reference signs S0 to S3 are arranged.
[0040]
The variable shaping blocks S0 to S3 are provided with square openings. Each of the variable shaping blocks S0 to S3 has the same function as the second slit 4 shown in FIG. That is, the beam cross section is made into a rectangle of an arbitrary size. In FIG. 5B, no blocks are arranged in the left, lower left, and lower width areas of the variable shaping blocks S0 to S3, which are areas that shield electron beams.
[0041]
FIG. 6A shows a part of the exposure data input to the electron beam block exposure apparatus. The exposure data includes a pattern identification field and a block identification field. A value for specifying a pattern to be exposed is stored in the pattern identification field, and a serial number of a block used when the pattern is exposed is stored in the block identification field. For example, the pattern A is exposed using the serial number 1 block, and the pattern B is exposed using the serial number 2 block.
[0042]
FIG. 6B shows the correspondence between the serial number of the block and the deflection control waiting time. Serial numbers 0 to 99 correspond to “LG” with a long deflection control waiting time, and serial numbers 101 correspond to “ST” with a short deflection control waiting time. This correspondence relationship is stored in advance in the control device 10 of the electron beam block exposure apparatus.
[0043]
As shown in FIG. 6A, the block number “101” is assigned to the dummy pattern C. The block number 101 means that any one of the variable shaping blocks S0 to S3 is used and the deflection control waiting time is shortened.
[0044]
In the third embodiment, the deflection control waiting time is defined by setting a specific value (“101” in the above embodiment) in the block identification field. That is, information regarding the deflection control waiting time associated with each pattern is stored in the block identification field of the exposure data. For this reason, it is possible to associate information on the deflection control waiting time for each pattern without adding a new field to the exposure data.
[0045]
Next, an electron beam exposure method according to the fourth embodiment will be described with reference to FIGS.
As shown in FIG. 7A, a plurality of main deflection fields 41 are defined in the plane of the wafer 40. As shown in FIG. 7B, a plurality of sub deflection fields 42 are defined inside each of the main deflection fields 41. As shown in FIG. 7C, dummy patterns A to J and device patterns K to N are defined in the sub deflection field 42.
[0046]
When exposing a pattern in one sub deflection field 42, the deflection direction by the main deflector 8 shown in FIG. 1 is fixed, and only the sub deflector 7 is controlled to scan the electron beam. When the exposure of all the patterns in one sub deflection field 42 is completed, the deflection direction by the main deflector 8 is changed so that the adjacent sub deflection field 42 is irradiated with an electron beam.
[0047]
When the exposure of all the sub-deflection fields 42 in one main deflection field 41 is completed, the wafer 9 is moved by operating the stage 9 in FIG. 1, and the exposure in the other main deflection field 41 is performed.
[0048]
FIG. 8 shows an example of the deflection stabilization characteristic of the main deflector 8. The horizontal axis represents the elapsed time from the completion of exposure of all patterns in one sub-deflection field in the unit of “μs”, and the vertical axis represents the deflection deviation (from the desired position to the actual electron beam incident position). (Shift amount) is expressed in units of “nm”.
[0049]
The behavior of the deflection deviation with respect to the elapsed time is the same as the deflection stabilization characteristic of the sub deflector shown in FIG. However, the unit of the horizontal axis of the deflection stabilization characteristic of the sub deflector is “ns”, whereas the unit of the horizontal axis of the deflection stabilization characteristic of the main deflector is “μs”.
[0050]
In order to set the positional deviation of the incident position of the electron beam to a tolerance of 5 nm or less for the positional deviation of the device pattern, it is necessary to secure a deflection control waiting time of about 400 μs. On the other hand, a deflection control waiting time of about 30 μs may be ensured in order to make the positional deviation less than the dummy pattern positional deviation tolerance of 50 nm.
[0051]
When exposing the pattern in the sub deflection field 42, first, a dummy pattern having a large positional deviation tolerance is exposed. After the exposure of all the dummy patterns in the sub deflection field 42 is completed, the device pattern having a small misalignment tolerance is exposed. When the elapsed time until the exposure of all the dummy patterns is over 400 μs, the deflection deviation of the main deflector is already 5 nm or less at that time. For this reason, it is only necessary to determine the deflection control waiting time while paying attention only to the deflection stabilization characteristics of the sub deflector without considering the deflection stabilization characteristics of the main deflector. Even if the elapsed time until the exposure of the dummy pattern is less than 400 μs, the total waiting time can be shortened.
[0052]
For example, if the exposure time of one dummy pattern is 200 ns and the deflection control waiting time is 50 ns, the time required to expose 1600 dummy patterns is exactly 400 μs. After 1600 dummy patterns are exposed under this condition, the deflection control waiting time may be determined by paying attention only to the deflection stabilization characteristics of the sub deflector.
[0053]
Next, an electron beam exposure method according to the fifth embodiment will be described with reference to FIG.
FIG. 9A shows one rectangular pattern 50 to be exposed. As shown in FIG. 9B, one pattern 50 is divided into ten sub patterns 50A to 50J. The divided sub-patterns 50A to 50J are different from the exposure unit patterns A1 to A8 and the like divided according to the predetermined division rule shown in FIG. Each of the sub patterns 50A to 50J corresponds to the pattern A or B to be exposed shown in FIG. 4A, and is recognized as one pattern in the exposure data.
[0054]
Each of the sub-patterns 50A to 50D is in contact with four sides of the original pattern 50 to be exposed and has a thin linear shape extending along the corresponding side. The other sub patterns 50E to 50J are not in contact with the outer peripheral line of the original pattern 50, and are arranged without a gap in the region surrounded by the sub patterns 50A to 50D.
[0055]
By making the sub-patterns 50A to 50D that define the outer periphery of the original pattern 50 into thin lines, the influence of the Coulomb effect can be reduced and the resolution with adjacent patterns can be increased.
[0056]
The sub-patterns 50 </ b> A to 50 </ b> D that define the outer peripheral line of the original pattern 50 are required to have the same position accuracy as that required for the original pattern 50. However, high positional accuracy is not required for the sub-patterns 50E to 50J that do not contact the outer peripheral line. It suffices if the interior of the pattern 50 is completely filled with the sub-patterns 50E to 50J. For this reason, the deflection control waiting time when the sub patterns 50E to 50J are exposed can be shortened.
[0057]
FIG. 9C shows part of the exposure data. The format of this exposure data is the same as the format of the exposure data shown in FIG. The long waiting time “LG” is associated with the sub-patterns 50A to 50D, and the short waiting time “ST” is associated with the sub-patterns 50E to 50J.
[0058]
By performing exposure using this exposure data, the processing time can be shortened compared to the case where the deflection control waiting times of all the sub-patterns 50A to 50J are the same.
[0059]
Next, a method for creating exposure data used in the above-described embodiment will be described. Generally, exposure data is generated from LSI design data. The design data is generally expressed in the GDS format proposed by the US company Karma. The GDS format includes a pattern identification field for specifying an LSI pattern and a layer information field for defining a layer on which the pattern is arranged.
[0060]
Conventionally, the same layer number is given to the dummy pattern and the device pattern in the same layer. In the above-described embodiment, different layer numbers are assigned to the dummy pattern having a larger positional deviation allowable error than the predetermined reference value and the device pattern having a smaller positional deviation allowable error than the predetermined reference value. For example, the layer number of the device pattern of the same layer is set to 1, and the layer number of the dummy pattern is set to 10.
[0061]
When the exposure data shown in FIG. 2B is generated from this design data, “LG” is set in the waiting time field of the pattern with the layer number “1”, and “ “ST” is set.
[0062]
In this way, information that defines the deflection control waiting time of exposure data is set based on the value of the layer information field of the design data. Thereby, it is possible to associate the deflection control waiting time for each pattern without adding a new field to the design data.
[0063]
Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.
[0064]
The invention shown in the following supplementary notes is derived from the above embodiments.
(Appendix 1) an electron gun that emits an electron beam;
A stage for holding the wafer at a position where an electron beam emitted from the electron gun is incident;
A first deflector that changes a traveling direction of the electron beam so that an incident position of the electron beam moves on a wafer held on the stage;
A shutter that shields the electron beam so that the electron beam emitted from the electron gun does not enter the wafer held on the stage;
For each of the plurality of patterns transferred to the wafer, exposure data including a pattern identifier for specifying the pattern, position information to which the pattern is transferred, and waiting time information is stored, and the first data is based on the position information of the exposure data. And a control device for controlling the shutter so that an electron beam is incident on the wafer after a lapse of time based on the waiting time information.
An electron beam exposure apparatus.
[0065]
(Supplementary Note 2) For each pattern to be transferred, the exposure data includes a division rule information field in which a value defining a division rule for exposing the pattern in a plurality of times is stored. 2. The electron beam exposure apparatus according to appendix 1, defined by a specific value stored in the division rule information field.
[0066]
(Appendix 3) Further, a block mask including a plurality of blocks arranged in an electron beam path between the electron gun and the stage, each of which is formed with a standardized figure that transmits the electron beam,
A second deflector for controlling the electron beam so that the electron beam passes through one block selected from a plurality of blocks of the block mask;
The exposure data includes a block identification field in which a value defining a block corresponding to the pattern is stored for each pattern to be transferred, and the waiting time information is stored in the block identification field The electron beam exposure apparatus according to appendix 1, which is defined by a specific value.
[0067]
(Appendix 4) (a) A plurality of upper deflection fields are defined on the surface of the wafer to be exposed, and a plurality of lower deflection fields smaller than the upper deflection field are defined inside each of the upper deflection fields, A plurality of patterns to be exposed are defined within each of the lower deflection fields, and the plurality of patterns are classified into at least two first and second sections according to the required position accuracy, Preparing the wafer that requires higher positional accuracy than the pattern belonging to the second category for the pattern belonging to the category; and
(B) exposing a pattern to be exposed in one lower deflection field of the wafer by scanning an electron beam with a lower deflector;
(C) controlling the upper deflector so that an electron beam can be irradiated in the lower deflection field that is not exposed;
(D) exposing a pattern belonging to the second section in the lower deflection field in which the electron beam irradiation is enabled in the step (c);
(E) exposing a pattern belonging to the first section in the lower deflection field after exposure of the pattern belonging to the second section;
An electron beam exposure method comprising:
[0068]
(Supplementary Note 5) In the step of dividing one pattern to be exposed on the wafer into a plurality of first sub-patterns in contact with the outer peripheral line of the pattern and at least one second sub-pattern not in contact with the outer peripheral line Each of the first sub-pattern and the second sub-pattern is divided into first and second sub-patterns that are irradiated with an electron beam without scanning the electron beam;
The deflector is controlled so that the electron beam is irradiated to one pattern selected from the first sub-pattern and the second sub-pattern, and the electron beam is actually irradiated after the deflection control waiting time has elapsed. And the process
And an electron beam exposure method in which a deflection control waiting time when the second sub pattern is selected is shorter than a deflection control waiting time when the first sub pattern is selected.
[0069]
(Supplementary Note 6) A step of creating design data having a pattern identification field for specifying a pattern of each layer of a semiconductor integrated circuit device and a layer information field for specifying a layer on which the pattern is arranged, and an allowable error of misalignment Creating design data so that the value of the layer information field is different between a pattern having a value larger than the reference value and a pattern smaller than the reference value;
A step of creating exposure data in a format that can be input to an electron beam exposure apparatus based on the design data, the exposure data including information defining a deflection control waiting time for each pattern to be exposed; A step of setting information for defining the deflection control waiting time based on the value of the layer information field of the design data;
A step of exposing the wafer based on the exposure data;
An electron beam exposure method comprising:
[0070]
【The invention's effect】
As described above, according to the present invention, by setting the deflection control waiting time for each pattern to be exposed, it is possible to shorten the deflection control waiting time for a pattern having a large misalignment tolerance. Thereby, processing time can be shortened.
[Brief description of the drawings]
FIG. 1 is a schematic view of an electron beam exposure apparatus according to an embodiment.
FIG. 2 is a plan view showing an arrangement of patterns to be exposed and a part of exposure data for explaining the electron beam exposure method according to the first embodiment.
FIG. 3 is a graph showing a deflection stabilization characteristic of a sub deflector.
FIG. 4 is a plan view showing the arrangement of patterns to be exposed for explaining the electron beam exposure method according to the second embodiment, a chart showing a part of exposure data, and the correspondence between division rules and waiting times. It is a chart shown.
FIG. 5 is a schematic view of an electron beam block exposure apparatus and a schematic plan view of a block mask.
FIG. 6 is a chart showing a part of exposure data used in the electron beam exposure method according to the third embodiment, and a chart showing a correspondence relationship between block serial numbers and waiting times.
FIG. 7 is a plan view of a wafer, a plan view of a main deflection field, and a plan view showing a pattern arrangement in a sub-deflection field for explaining an electron beam exposure method according to a fourth embodiment.
FIG. 8 is a graph showing a deflection stabilization characteristic of the main deflector.
FIG. 9 is a plan view of one pattern for explaining an electron beam exposure method according to a fifth embodiment, a plan view showing a plurality of sub-pattern arrangements, and a chart showing a part of exposure data.
[Explanation of symbols]
1 electron gun
2 First slit
3 Slit deflector
4 Second slit
4A block mask
5 Blanking
6 Aperture
7 Sub deflector
8 Main deflector
9 stages
10 Control device
15 lenses
20 wafers
30 block select back deflector
40 wafers
41 Main deflection field
42 Sub-deflection field
50 Patterns to be exposed

Claims (3)

(A) A plurality of upper deflection fields are defined on the surface of the wafer to be exposed, and a plurality of lower deflection fields smaller than the upper deflection fields are defined within each of the upper deflection fields, and the lower deflection fields A plurality of patterns to be exposed are defined in each of the plurality of patterns, and the plurality of patterns are classified into at least two first sections and second sections according to required position accuracy, and belong to the first section. Preparing a wafer that requires a higher positional accuracy than a pattern belonging to the second section in a pattern; and
(B) exposing a pattern to be exposed in one lower deflection field of the wafer by scanning an electron beam with a lower deflector;
(C) controlling the upper deflector so that an electron beam can be irradiated in the lower deflection field that is not exposed;
(D) exposing a pattern belonging to the second section in the lower deflection field in which the electron beam irradiation is enabled in the step (c);
And (e) exposing a pattern belonging to the first division in the lower deflection field after exposure of the pattern belonging to the second division. A plurality of upper deflection fields are defined on the surface of the wafer to be exposed, and a plurality of lower deflection fields smaller than the upper deflection fields are defined within each of the upper deflection fields, and each of the lower deflection fields is defined. Providing the wafer internally defining a plurality of patterns to be exposed;
Dividing one pattern to be exposed on the wafer into a plurality of first sub-patterns in contact with the outer periphery of the pattern and at least one second sub-pattern not in contact with the outer periphery; Dividing each of the first sub-pattern and the second sub-pattern into first and second sub-patterns irradiated with an electron beam without scanning the electron beam;
Controlling the upper deflector so that it can be irradiated with an electron beam in the lower deflection field to be exposed next;
Exposing the second sub-pattern in the lower deflection field enabled to be irradiated with an electron beam;
Exposing the first sub-pattern in the lower deflection field after exposure of the second sub-pattern in the lower deflection field enabled to be irradiated with an electron beam;
An electron beam exposure method comprising: A step of creating design data having a pattern identification field for specifying a pattern of each layer of a semiconductor integrated circuit device and a layer information field for defining a layer on which the pattern is arranged, and the position of the patterns in the same layer The first value and the second value are set in the layer information field so that the value of the layer information field is different between the pattern having a deviation tolerance larger than the reference value and the pattern smaller than the reference value . The process of creating design data;
A step of creating exposure data in a format that can be input to an electron beam exposure apparatus based on the design data, the exposure data including information defining a deflection control waiting time for each pattern to be exposed; A step of setting information for defining the deflection control waiting time based on the value of the layer information field of the design data;
On the basis of the exposure data, the first value and the pattern in which the second value is set to Yes and performing exposure of wafer to be transferred in the same layer in the layer information field,
A plurality of upper deflection fields are defined on the surface of the wafer, and a plurality of lower deflection fields smaller than the upper deflection field are defined within each of the upper deflection fields, and each of the lower deflection fields is disposed within each of the upper deflection fields. A plurality of patterns to be exposed are defined, the plurality of patterns are classified into at least two first sections and second sections, and the deflection control waiting time of the patterns belonging to the first section is Longer than the deflection control waiting time of the pattern belonging to the second section,
The step of exposing the wafer comprises:
Controlling the upper deflector so that it can be irradiated with an electron beam in the lower deflection field to be exposed next;
Exposing a pattern belonging to the second section in the lower deflection field enabled to be irradiated with an electron beam;
Exposing the pattern belonging to the first section in the lower deflection field after exposure of the pattern belonging to the second section;
An electron beam exposure method comprising :

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