JP3079514B2 - Electron beam writing system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides an electron beam deflection control on the sample, when drawing the like LSI pattern on a sample, and high processing efficiency with the simultaneous multiple control, a diverse range of drawing pattern The present invention relates to an electron beam writing system having flexibility for performing processing efficiently .

[0002]

2. Description of the Related Art As one of methods for improving the processing capacity (throughput) per unit time of an electron beam writing apparatus,
For example, a simultaneous control method described in JP-A-62-57215 has been proposed. This is a method of simultaneously controlling a plurality of drawing units. In each of these drawing units, one control unit which performs management of system and pattern data, and calculation of drawing coordinate data and exposure time data is electronically controlled. The optical system includes an optical system, an analog deflection system, various correction systems, a sample stage system, and the like. According to this control method, the pattern data is simultaneously sent from the control unit to the plurality of drawing units, so that it is possible to perform writing on a plurality of samples at the same time. Therefore, the throughput of the drawing apparatus is improved in proportion to the number of drawing units that are controlled simultaneously.

[0003]

However, in the above-described configuration according to the prior art, although a plurality of drawing units are provided, there is a restriction that the drawing units must always draw the same pattern at the same time. Therefore, even when it is necessary to process a plurality of different writing patterns, each writing pattern must be processed in series regardless of the amount of the sample to be written. Therefore, every time the drawing pattern changes, a drawing waste time for preparing the drawing data occurs. That is, the conventional technique is advantageous when processing a large number of patterns of one type, but lacks the flexibility for processing a plurality of drawing patterns. In such a case, it is more efficient to independently use a plurality of normal drawing apparatuses each including one control unit and one drawing unit because preparation of drawing data and drawing can be processed in parallel. It can be said. Further, when controlling a plurality of drawing units simultaneously, it is assumed that the processing capabilities of the drawing units are uniform. However, in reality, electron-optical characteristics such as current density and deflection settling time, and mechanism transfer characteristics such as a sample transfer speed and a vacuum pumping speed are different for each drawing unit. Therefore, even if the pattern to be drawn is the same, the time required for processing differs for each drawing unit. Therefore, the timing at which the control unit supplies data to the drawing unit needs to be adjusted to the drawing unit that requires the longest drawing processing time, so that the processing speed of the drawing system is limited by the processing capability of the drawing unit with the lowest processing capability. Will be done. Therefore, an object of the present invention is to solve the above-described problems in a drawing system configured by a plurality of drawing apparatuses, and to efficiently perform high processing efficiency of simultaneous multiple control and processing of various drawing patterns. It is an object of the present invention to provide an electron beam lithography system and method capable of achieving both of the flexibility of the present invention and a semiconductor device using the same.

[0004]

Means for Solving the Problems] To achieve the above object, an electron beam writing system of the present invention, the drawing data
Data preparation, drawing data supply and drawing procedure management
A control computer unit, and an electronic beam from the drawing data.
Drawing control that calculates and controls the deflection coordinates of the system and the exposure time
And an analog bias for deflecting the coordinate data with a deflector.
Direction control and a correction calculation system for correcting the coordinate data
Control, stage control to control stage movement, signal processing
Control, vacuum control, sample stage and electron optics
Electron beam lithography system with a lithography unit
Through a network between the electron beam writing apparatuses.
In an electron beam writing system that exchanges data by
The plurality of drawing control units include a drawing coordinate data bus and an exposure
Time data bus, control signal bus, and status signal bus
Bidirectionally input and output, and connect between the outputs of the plurality of drawing control units.
A signal transmission path that continues, provided in the signal transmission path,
Controlled by the control signal transmission line from the control computer
And a signal transmitted on the control signal transmission path.
Bus control to control data direction and connection status
It is characterized by connecting to the In addition, the
Controller at the bus connection point in the signal transmission path
It is also characterized by being done. Further, the signal transmission
Roads use electrical signals or optical signals
The feature of using one or both of
I have. Thus, according to the drawing system of the present invention, each drawing apparatus constituting the system independently processes a plurality of drawing patterns, and a plurality of drawing units simultaneously process one pattern at a high speed. Both forms can be adopted. Further, it becomes possible to share data necessary for drawing between drawing apparatuses. Therefore, high processing efficiency and flexibility for processing various patterns can be achieved at the same time, and drawing can be performed efficiently.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of an electron beam writing system showing one embodiment of the present invention. As shown in FIG. 1, the electron beam writing system 115 of the present invention includes:
It is composed of a plurality of electron beam writing devices 114 and one sample transport device 125. The electron beam writing apparatus 114 includes a control computer unit 101, a writing control unit 10
2 and a drawing unit 103. The control computer unit 101 controls the type and
Obtain information on the previous and next processes and the operation status of the equipment
To determine which parallel electron beam lithography system to process.
Set. The drawing control unit 102 is a shared database
Drawing image data memory 116 is constituted coordinate calculation control unit 117 calculates the deflection coordinates of the electron beams, and exposure time from an exposure time calculation control unit 118 which calculates from the drawing data, the deflection coordinates and exposure of the electron beam from the drawing data The time is calculated and each control is performed. Drawing unit 103
Is composed of a correction operation control 104, an analog deflection control 105, a sample stage 109, a stage control 107, a signal processing control 106, a vacuum control 108, an electron optical mirror 110, and the like. The electron optical mirror 110 includes an electron gun 119, a deflector 121, a lens 124, a backscattered electron detector 122, and the like. The control computer unit 101, the drawing control unit 102, the drawing unit 103, and the sample transport device 125 are connected by signal transmission paths 111 and 112, so that data and signals necessary for drawing can be mutually exchanged. I have. Also, the drawing system 115
Is connected to a LAN (local area network) 113 or the like in a semiconductor device production factory, and is capable of connecting to a shared database 126 and exchanging data with another device 127.

(First Embodiment) FIG. 2 is a diagram showing an example of an operation mode of the drawing system in FIG. Here, a method of performing drawing while exchanging drawing data and the like between drawing apparatuses will be described. As shown in FIG. 2A, the drawing system 115 includes three drawing devices A201, B202,
It is composed of C203 and sample transport device 125.
Now, an example of signal transmission / reception when the drawing apparatus A201 is drawing a certain drawing pattern and then the drawing apparatuses B202 and C203 start drawing the same drawing pattern as the drawing apparatus A201. Drawing apparatus B202, C
Reference numeral 203 denotes the signal transmission paths 111 and 112 for drawing data in a state where the drawing processing is performed by the drawing apparatus A201 and data of each parameter for determining drawing conditions and the like.
Forwarded over. Since the preparation for drawing is completed when the transfer is completed, drawing can be started immediately. Therefore, FIG.
As shown in (b), in the drawing processing time of the drawing apparatuses B202 and C203, the preparation time of drawing data, which is conventionally required, is reduced to the data transfer time, so that the processing efficiency can be improved. The broken line portion in FIG. 2B is the transfer time when the data is not shortened.

(Second Embodiment) FIG. 3 is a diagram showing a method for performing drawing by changing the operation mode of the drawing system of the present invention. In the present embodiment, drawing is performed by changing the operation mode of the drawing system by setting the connection state of the signal transmission lines connecting the components of the drawing apparatus. The drawing system 115 includes four drawing devices and one sample transfer device 125. Drawing system 115
Operating mode, that is, the combination of each part, the drawing data obtained via the network 113, the information on the manufacturing process of the semiconductor device, the drawing data for each lot, the drawing priority of each lot, the operating status of the electron beam drawing system and Depending on the processing capacity of each drawing unit,
It is determined by selecting the connection state of the signal transmission lines 111 and 112 according to the judgment of the control computer unit 101 or the setting of the operator. Hereinafter, a method for determining the combination will be described. Here, the control computer unit A301 determines the operation mode of the drawing system 115.
The control computer unit A301 determines that lots to be processed next via the LAN 113 are A302, B303, and C304.
And that the ratio of the number of wafers constituting each lot is Na: Nb: Nc = 1: 1: 1, and that the type of writing data for each lot is PA, PB, P
C, information on the priority of lot processing, the next process of each lot, and the operation status of the equipment used in that process. Control computer unit A301
Determines the optimal processing mode based on the information and the current operating status of the drawing system.

First, a lot A 302 is obtained from information on the type and priority of the drawing pattern, information on the next process and the operation status of the apparatus, and information on the current flexibility status of the writing system.
It is determined that B303 and C304 are processed in parallel.
Further, the lot assigned to each of the control computer units A to C is determined. Next, each lot A302, B303, C3
The number of writing control units 102 and writing units 103 required for processing are determined from the writing time that can be known from the number of constituent wafers 04 and the type of writing pattern. Finally, the connection state of the signal transmission lines 111 and 112 is determined, and the combination of each unit is set. For example, in this embodiment, since the drawing patterns PA and PB are contact hole patterns and PC is a wiring pattern, each wafer 1
The ratio of the drawing times ta, tb, tc per sheet is 1: 1: 2.
It turns out that. Therefore, the total processing time Ta,
Since Tb and Tc each have a ratio of the number of constituent wafers Na, Nb and Nc of 1: 1: 1, Ta: Tb: Tc =
1: 1: 2. Therefore, lots A302, B30
3, the four drawing units for the respective processes of C304 are divided at a ratio of 1: 1: 2, and the combinations 305, 306,
307 was determined. Of the signal transmission paths 111 and 112,
The solid line indicates a selected and operating state, and the dashed line indicates an inactive state. At this time, the control computer unit d308 monitors the operation status of each of the combinations 305, 306, and 307, since the control of the drawing is not performed.
In particular, the drawing state of the drawing unit 103 is grasped via the LAN 113, and the sample transport device 125 is controlled according to the state. The sample transport device 125 includes a control computer unit D3
Samples are taken in and out according to the instructions of 08.

FIG. 4 is an explanatory diagram of a drawing processing time according to an embodiment of the present invention. FIG. 4A shows lots A, B,
FIG. 4B shows the drawing processing time when the drawing processing is performed by the conventional simultaneous multiple control method. Since all the drawing units simultaneously draw the same pattern, the drawing processing time for each lot is reduced to 1/4. However, since the lots A, B, and C are serially processed in this order, the drawing data preparation time (Tp) becomes the drawing impossible time. FIG. 4C shows the drawing processing time when the drawing processing is performed by the method of the present invention. Since the lots A, B, and C are processed in parallel, the non-drawing time can be reduced, and the processing can be performed efficiently. Also,
Irrespective of the type of drawing pattern, the throughput of the exposure process can be kept constant, so that the efficiency of the manufacturing process can be improved.

(Third Embodiment) FIG. 5 is a block diagram of an electron beam writing system showing a third embodiment of the present invention.
In this embodiment, the drawing system 115 includes three drawing devices 5.
01, 502, and 503. However, the sample transport device is omitted here. FIG. 5A shows a case where all the three drawing units 103 are simultaneously controlled by a set of one control computer unit 101 and drawing control unit 102. This is a form of the conventional simultaneous multiple control method. Among the signal transmission paths 111 and 112, a solid line indicates a selected and operating state, and a broken line indicates an inactive state. The three drawing units 103 simultaneously process writing of one type of pattern in parallel. FIG. 5B shows a case where all the drawing units 103 are controlled by a set of separate control computer units 101 and drawing control units 102. Here, the sample transport device is omitted. This is a mode in which a plurality of normal drawing apparatuses are independently provided and used, and three different patterns can be processed independently. As described above, according to the present invention, it is possible to adopt a conventional simultaneous multiple control mode or a mode in which a plurality of normal drawing apparatuses are independently provided and used by a method of combining the respective units.

(Fourth Embodiment) FIG. 6 is an explanatory view of the configuration and operation of an electron beam writing system according to a fourth embodiment of the present invention, in which all three writing units 103 simultaneously write the same pattern. An example is shown in which the processing capability can be further improved. However, the illustration of the sample transport device is omitted here. As shown in FIG. 6A, two control computer units 101 and two drawing control units 102 are used in combination for controlling the drawing unit. Thereby, the control computer unit 101,
The functions of the drawing control unit 103, for example, when calculating the drawing coordinates and the exposure time for each shot, for each deflection range, or for each chip during drawing, the processing can be performed in a distributed manner. Can be reduced, and the drawing speed can be improved. FIGS. 6B and 6C show the processing time of this embodiment. FIG. 6B shows a case where the distributed processing is not performed.
A, B, C, and D are different deflection ranges, and show how calculations are performed for each deflection range during writing. If the calculation time is longer than the exposure time, an exposure waiting time occurs, and the processing speed decreases. FIG. 6C shows the case of the present embodiment, in which a set of two control computer units 101 and a drawing control unit 102 performs calculations in parallel for different deflection ranges. By doing so, the occurrence of the exposure waiting time can be suppressed, so that the processing speed is improved. Here, the processing is performed in parallel for different deflection ranges. However, it is also possible to perform calculations in the same deflection range in a distributed manner to reduce the exposure waiting time.

(Fifth Embodiment) FIG. 7 is an explanatory view of the configuration and operation of an electron beam writing system according to a fifth embodiment of the present invention. FIG. 7A shows a case where all the three drawing units 103 draw the same pattern at the same time, but a combination 701 that does not include a drawing unit.
Is an example in which preparation of drawing data to be drawn next is performed in parallel during drawing. However, the illustration of the sample transport device is omitted here. When the writing pattern changes for each chip, or when a large pattern is written in a large area over the entire surface of the sample and divided and drawn, it is necessary to frequently prepare the writing data. In such a case, a waste time for preparing drawing data is generated between drawing and the processing efficiency is deteriorated. FIG. 7B is a diagram for explaining the situation.
A, B, C, and D indicate different patterns. When the parallel processing is not performed, the drawing is temporarily stopped when one pattern is drawn, and a waste time is generated to prepare the data, thereby reducing the processing efficiency. FIG.
(C) shows the case of the present embodiment. In the present embodiment, data is prepared in parallel with drawing.
Further, in the preparation, since the distributed processing is performed by using two control computers 101 and two drawing controllers 102, the processing time is reduced to half. Since the preparation of the next data is completed during the drawing, only the time for data transmission is required between the drawing and the dead time is reduced. Therefore, processing efficiency is significantly improved.

(Sixth Embodiment) FIG. 8 is an explanatory diagram showing the configuration and operation of an electron beam writing system according to a sixth embodiment of the present invention. FIG. 8A shows a case where all the drawing units 103 draw the same pattern at the same time, but the drawing control unit 102 and the drawing unit 103 each have one.
This is a case where the control computer unit 101 is combined with each other so as to be controlled one by one. Drawing control unit 1
02 is provided with a drawing data memory 116 having a capacity capable of storing data for one chip. Although the drawing data is simultaneously supplied from the control computer unit 101 to each drawing data memory 116, the drawing data can be read from each drawing data memory 116 at an arbitrary timing.
Therefore, the drawing control units 102 and below can perform drawing independently. Therefore, even if there is a difference in the processing capability of the drawing unit 103, the drawing time difference caused by the difference in the processing capability is absorbed, and a drawing unit with a low processing capability does not limit the processing capability of the drawing system. FIG. 8B
FIG. 3 is a diagram for explaining a drawing time of a conventional method not via a drawing pattern memory, paying attention to each shot. A,
B and C are different drawing units, and the time (shot time) required for a constant exposure amount is different due to variations in the electro-optical characteristics. In the conventional configuration, data must be supplied from the drawing control unit to all the drawing units at the same timing. Therefore, the update of the shot data is limited by the exposure unit having the longest shot time. FIG. 8C illustrates the case of the present embodiment. Since data can be given from the drawing control unit to all the drawing units at a timing corresponding to the processing capability of each drawing unit, there is no need to wait for the end of the shot of the slow drawing unit. Is not limited by a drawing unit having a low processing capacity.

(Seventh Embodiment) FIG. 9 is a block diagram of an electron beam lithography system showing a seventh embodiment of the present invention.
Here, one drawing device 901 and one drawing control unit 9
02 shows a case where the drawing system is configured. In this embodiment, components can be added to or deleted from the drawing apparatus 901 in units of components. In this configuration example, the drawing control unit 1 in the drawing device 901
02 to the drawing control unit 902 to which the processing of FIG.
Since the added drawing control unit 902 can prepare the next drawing data in parallel with the drawing, the processing efficiency can be improved.

(Eighth Embodiment) FIG. 10 shows an eighth embodiment of the present invention.
1 is a configuration diagram of an electron beam writing system showing an embodiment of FIG. FIG. 10A shows a specific example of the signal transmission lines 111 and 112 that couple the respective components. here,
A drawing system constituted by two drawing apparatuses A 1015 and B 1016 will be described as an example. Control computer section A
A signal transmitted and received between the drawing control unit A1010 and the drawing control unit A1010 is processed by the control computer unit A1009, the drawing data in a format usable by the drawing control unit A1010, and a dedicated control CPU in the drawing control unit A1010.
And a status signal indicating the state of the drawing control unit A1010 and the drawing unit A1011. Therefore, the control computer unit A1009 and the drawing control unit A10
The signal transmission lines between the drawing data bus 1001, the control signal bus 1002, and the status signal bus 10
03. A signal transmitted and received between the drawing control unit A1010 and the drawing unit A1011 is transmitted to the drawing control unit A1010.
10 is a status signal indicating the drawing coordinate data and the exposure time data calculated in Step 10 and the state of the drawing unit A1011. Therefore, the drawing control unit A1010 and the drawing unit A101
The signal transmission path between the control signal bus 1005 and the drawing coordinate data bus 1005, the exposure time data bus 1006, and the control signal bus 10
07 and a status signal bus 1008. All buses are bidirectional buses. The same applies to the drawing apparatus B1016, and the corresponding buses are connected between the drawing apparatuses A1015 and B1016. Black circles in the figure indicate connection points of the bus. A bus controller 1004 is provided at each connection point. Since each bus controller 1004 and each control computer unit 1009, 1012 are connected by control signal transmission lines 1017, 1018 as shown in FIG. 9B, the bus controller 1004 can be controlled from any control computer unit. . The bus controller 1004 controls the transmission direction and connection state of the bus according to an instruction from the control computer unit. Each signal transmission path is not limited to one using an electric signal or one using an optical signal.

(Ninth Embodiment) FIG. 11 shows a ninth embodiment of the present invention.
FIG. 7 is a diagram for explaining the manufacturing process of the semiconductor device according to the embodiment of the present invention. On the N minus silicon substrate 1101, a P well layer 1102, a P layer 1103, a field oxide film 1104, a polycrystalline silicon / silicon oxide film gate 1105, a P high concentration diffusion layer 1106, and a N high concentration diffusion layer 1 are formed in a usual manner.
107 and the like were formed (FIG. 11A). Next, an insulating film 1108 of phosphorus glass (PSG) was applied by a usual method. Further, a lot A (FIG. 11B) composed of a wafer on which a photoresist 1109 is applied, a W / TiN electrode wiring 1112 is formed through other steps, and then an interlayer insulating film 1113 is formed. And a lot B composed of a wafer coated with a photoresist 1119
(FIG. 11E). The next is an exposure step for both lots A and B, which are processed by an electron beam drawing apparatus. The exposure apparatus of the present invention is applied to a drawing apparatus. Therefore, the processes of the exposure processes of the lot A and the lot B can be performed simultaneously. In the wafer of the lot A, the exposure of the hole pattern was performed by the electron beam 1110 (FIG. 11C). Thereafter, as a result of development, a hole pattern 1111 was formed as shown in FIG. For the lot B wafer,
The exposure of the hole pattern was performed by the electron beam 1110 (FIG. 11F). Then, as a result of development, FIG.
As shown in (g), a hole pattern 1114 was formed. Except for the subsequent exposure steps, the conventional method was used. As described above, the drawing apparatus to which the drawing method of the present invention is applied can simultaneously perform processing of wafers on which different types of patterns are drawn. Since the processing proceeded without waiting for the processing of a different wafer, other types of LS
I could be manufactured in a short time.

[0017]

As described above in detail, according to the electron beam lithography system and the lithography method of the present invention, necessary data can be exchanged between the respective devices, and the drawing dead time can be reduced. Also, since a plurality of forms can be selected depending on the combination of the components, a single pattern can be processed at a higher speed and a plurality of patterns can be processed in parallel.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electron beam writing system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method of performing drawing while transferring data between drawing apparatuses in FIG. 1;

FIG. 3 is a configuration diagram of an electron beam writing system according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a drawing processing time in FIG. 3;

FIG. 5 is a configuration diagram of an electron beam writing system according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram and an explanatory diagram of processing time of an electron beam writing system according to a fourth embodiment of the present invention.

FIG. 7 is a configuration diagram and a processing time explanatory diagram of an electron beam writing system according to a fifth embodiment of the present invention.

FIG. 8 is a configuration diagram and a processing time explanatory diagram of an electron beam writing system according to a sixth embodiment of the present invention.

FIG. 9 is a configuration diagram of an electron beam writing system according to a seventh embodiment of the present invention.

FIG. 10 is a configuration diagram and an enlarged view of an electron beam writing system according to an eighth embodiment of the present invention.

FIG. 11 is a view illustrating a method of manufacturing a semiconductor device according to a ninth embodiment of the present invention.

[Explanation of symbols]

101: control computer unit, 102: drawing control unit, 1
03: Drawing unit, 104: Various correction arithmetic control, 105: Analog deflection system, 106: Signal processing control, 107: Stage control, 108: Vacuum control, 109: Sample stage, 110: Electro-optical mirror, 111, 112 ...
Signal transmission line, 113, network, 114, electron beam writing apparatus, 115, electron beam writing system, 201, 202, 203, combination, 40
DESCRIPTION OF SYMBOLS 1 ... Combination, 301, 302, 303 ... Electron beam drawing apparatus, 601 ... Sample conveyance apparatus, 602, 603 ... Sample, 701 ... N minus silicon substrate, 702 ... P well layer, 703 ... P layer, 704 ... Field oxide film , 70
5 ... polycrystalline silicon / silicon oxide film gate, 706 ...
P high concentration diffusion layer, 707: N high concentration diffusion layer, 708: insulating film, 709: resist, 710: electron beam, 71
1, 714: hole pattern, 712: electrode wiring, 71
3. Interlayer insulating film.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hidetoshi Sato 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory of Hitachi, Ltd. (56) References JP-A-6-216014 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/027

Claims (3)

(57) [Claims] 1. Preparation of drawing data, supply of drawing data and
And a control computer unit having a control of a writing procedure and a deflection coordinate and an exposure time of an electron beam from the writing data.
A drawing control unit that performs calculation and control, and an analog deflection system for deflecting coordinate data with a deflector
Correction calculation control for correcting and calculating the coordinate data;
Stage control and signal processing system to control stage movement
Control, vacuum control, sample stage and electron optical mirror
A plurality of electron beam lithography systems equipped with a lithography unit
Then, the electron beam lithography devices are connected to each other through a network.
In the electron beam writing system for transferring data, the plurality of writing control units include a writing coordinate data bus and an exposure coordinate data bus.
Time data bus, control signal bus, and status signal bus
Bidirectionally input and output, and connect between the outputs of the plurality of drawing control units.
A signal transmission path connected to the control computer,
Controlled by the control signal transmission line, and the control signal
Connection with the direction of data by the signal transmitted on the transmission line
It is specially connected to the bus controller that controls the status.
Electron beam writing system. 2. An electron beam writing system according to claim 1,
In arm, the bus controller, the bus signal transmission line connecting points
An electron beam writing system , wherein the electron beam writing system is installed in a computer. 3. An electron beam writing system according to claim 1,
The signal transmission line uses an electric signal or an optical signal.
Use one or both of
An electron beam drawing system characterized by the above-mentioned .