JPH02202012A - Charged particle beam lithography device - Google Patents

Abstract

PURPOSE:To unnecessitate a prealignment work by a method wherein a patterning is conducted using a lithography device while a sample stage is being moved in the direction almost in coincidence with the orientation flat direction of a substrate, or in the direction of a matching mark. CONSTITUTION:The offset amount between the orientation flat direction of the substrate 20 on a sample stage 33, or the direction of at least two prescribed alignment marks, and the coordinate value of the mark based on the coordinate value of the prescribed alignment mark and the design data, is detected. The sample stage 33 is shifted to the detected direction A, and based on the design correction data obtained on the basis of the detecting direction A and the offset amount, an auxiliary deflection command device 38 and a main deflection command device 39 are controlled, and a patterning is conducted on a wafer 20. As a result, the shifting of the sample stage 33 in X-direction or Y-direction is stopped, the sample stage 33 can be continuously shifted in the direction where chips are arranged, and a prealignment is unnecessitated.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention uses a charged particle beam such as an electron beam to draw on a substrate to be drawn, such as a wafer having an orientation flat or alignment mark, while continuously moving a sample stage. It relates to a drawing device.

(Prior Art) Conventionally, an electron beam drawing device that draws on a wafer having an orientation flat or an alignment mark while continuously moving a sample stage has been used to draw images on a wafer having an orientation flat or an alignment mark while continuously moving the sample stage. They are aligned to about 5 to 10 milliradians, and then aligned to about 1 milliradian by a pre-alignment device using alignment marks. Then, the prealigned wafer is mounted on a sample stage in the lithography chamber by the prealignment device.

(Problem M to be Solved by the Invention) Since such conventional devices require pre-alignment work, they require extra equipment and extra work, which is an obstacle to automation.

An object of the present invention is to eliminate the need for the above-mentioned pre-alignment work in a charged particle beam lithography apparatus that performs lithography while continuously moving a sample stage.

(Means for Solving the Problems) As shown in FIG. 1, which is a frame correspondence diagram, the present invention provides continuous movement of a sample stage to a substrate to be drawn, such as a tool having an orientation flat or alignment mark. In a charged particle beam lithography device that draws images while moving, the direction of the orientation flat of the substrate on the sample stage, or the direction of at least two predetermined alignment marks, and the direction of the marks based on the coordinate values of the predetermined alignment marks and design data. a detection means (2) for detecting an offset amount with respect to the coordinate value; a movement direction command means (3) for moving the sample stage in the direction detected by the detection means (2); ) is provided, and a correction means (4) corrects the coordinate values of the pattern based on the design data based on the detected direction and offset amount, and the sample stage is moved in the direction of the orientation flat of the substrate or in the direction of the alignment mark. Charged particle beam lithography apparatus (1, 2) characterized in that the lithography means (1) performs lithography while moving in a direction substantially coincident with
, 3, 4).

(Function) In the conventional drawing apparatus, drawing was performed while continuously moving the sample stage in the X direction or the X direction of the X-Y movement direction. Therefore, if the X direction or the X direction and the direction in which the chips to be drawn are arranged are out of alignment by more than a predetermined tolerance range, drawing cannot be performed, and thus pre-alignment is necessary.

In contrast, in the present invention, the X direction of the sample stage or
Since the sample stage is moved continuously in the direction in which the chips are lined up instead of moving in the same direction, conventional pre-alignment is no longer necessary.

(Example) FIG. 2 is a diagram illustrating the relationship between a wafer on a sample stage and a coordinate system in an example of the present invention. In Figure 2,
The wafer 20 is mounted on a sample stage (not shown) without pre-alignment. For this reason, the wafers are only mechanically aligned using a transport device, so when fishing on a boat, it is difficult to
It is tilted at an angle θ of about 10 milliradians.

FIG. 3 shows an electron beam lithography system according to an embodiment of the present invention, which performs lithography while continuously moving the sample stage while keeping the wafer 20 mounted as shown in FIG. It is a flowchart of a computer.

The computer 30 reads the mark coordinate values f(x,...!++) formed on the end chip (20a...FIG. 1) according to the design data from the command device 31 (steps in FIG. 4). 300), and the mark coordinate position (X
The computer 30 issues a driving command to the driving device 34 of the stage 33 so that the beam ll5)'i+) is located at a predetermined position (for example, the center, that is, the position i& on the axis of the electron optical system 32) of the main deflection area.

That is, the position of the stage 33 is fed back to the computer 30 by the coordinate reading device 35, and the computer 30 determines that the coordinate values (x, y) output by the coordinate reading device W35 are the coordinate position (X ++, 7++) and a predetermined value. The movement of the stage 33 is controlled so that the relationship is as follows (step 301).At this time, if the coordinate reading device 35 is outputting the coordinate values of a predetermined position in the main deflection area, the predetermined relationship is as follows. X=x, , Y −3′ r +.

In this way, the X-Y axis perpendicular to the axis of the electron optical system 32 is
Once the in-plane position is determined, the computer 30 uses the height information from the height detector 36 to direct the focus controller 37 to focus the objective lens of the electron optical system 32 on the surface of the wafer 20. A focus command is issued (step 302).

Next, the computer 30 causes the electron optical system 32 to start irradiating the electron beam (step 303L, the sub-deflection command device 38
, a control command is given to the main deflection command device 39 in a predetermined relationship, and mark coordinate values (X++', !++') are read based on the reflected electron information from the receiving device 40 (step 304).

Coordinate value of end chip 20a (X11'% 7Ir'
), the computer 30 stops irradiating the electron beam (step 305) and reads the corresponding mark coordinate position (xll, yl, ) to the command device 31
(step 306).

Then, the movement of the stage 33 is controlled so that the mark coordinate position (Xl++, yl,) is at a predetermined position of the main deflection MkA (step 307).

Then, electron beam irradiation is started (step 308),
The mark coordinate values (xl,'', yl,'') are read (step 309).

Then, the electron beam irradiation is stopped (step 310), and the computer 30 calculates the coordinate values of the two marks obtained earlier.
Offset amount of reference coordinate position (X18.31 +t) □
l+
/Yr+-7+-') (step 31
1).

The computer 30 corrects each coordinate position of the design data from the command device 31 using the offset amount and the stripe inclination determined in step 311, and stores it as design correction data (step 312).

Then, the computer 30 issues a drive command to the stage drive device 34 so that the moving direction of the stage 33 is the direction A of the stripes of the stage 33 and a direction perpendicular to this direction, and also uses the design correction data stored in step 312. Based on this, the sub-deflection command device 38 and the main deflection command bag W
39 to perform drawing on the wafer 20 (
Step 31.3).

Note that in the movement of the stage 20 in step 313 described above, if the wafer 20 is pre-aligned and the direction of the stripe matches the X direction as in the conventional case, the stage 20 is first moved in the X direction, When the exposure of one stripe is completed, the stage 20 is moved by a predetermined amount in the X direction, and the stripes at the intervals of the stripes are exposed. While moving the stage 20, 50X in the X direction
(X++° X+a') / (711' 7
The stage 20 is moved at a speed of (X++'X+a')/0't+.
' ) 'Ill' ) direction (Strive direction).

Furthermore, when the inclination angle θ of the wafer 20 is small, as shown by the broken line 21 in FIG. 1, the stage 33 is moved in the X direction while writing one chip, and the stage 33 is The stage 33 is moved by a predetermined amount in the X direction (where θ is the inclination of the wafer 2o) by a predetermined amount (if yo is the length of the l chip in the X direction, then yasinθ is yasinθ), and the stage 33 is moved again in the X direction by a predetermined amount (y.

cos θ), it may be possible to keep it within the error range.

Even when the stage 33 is moved in a zigzag pattern like this, when viewed as a whole, the stage 33 can be considered to be moving in the direction of the stripe.
In the present invention, the movement of the stage 33 as indicated by the broken line 21 in FIG. 1 is also included in its scope.

Further, in the above-described embodiment, marks formed on the chip are used to detect the tilt and offset of the wafer 20, but the tilt and offset of the wafer 20 can be detected by other means, for example, by detecting the tilt and offset of the wafer 20. Of course, if there is no mark provided or a special mark, the linear notch forming the orientation flat 22 may be measured and determined.

(Effects of the Invention) As described above, according to the present invention, there is no need to accurately align the direction of the wafer, and therefore no pre-alignment work is required.

In addition, in conventional equipment, the prealignment tolerance value is set to εr
ad, the field of view of the electron optical system is AXAm”, and the scanning width is am
, if the drawing area is YXXm'', then a≦A−1el・
Although it was possible to obtain only a small value of a that satisfies Y, the apparatus of the present invention can achieve a value of a/%yA, and the number of times the sample stage moves back and forth can be slightly reduced.

[Brief explanation of the drawing]

FIG. 1 is a frame correspondence diagram, FIG. 2 is a diagram showing the relationship between the x-y movement direction of the stage and the wafer, and FIG. 3 is a block diagram of an electron beam lithography system used as an embodiment of the present invention.
FIG. 4 is a flowchart of the computer of FIG. 3. (Explanation of symbols of main parts) 2...Detection means, 3...Movement direction command means, 4...Correction means, 30...Computer. Recruiter Nikon Co., Ltd.

Claims (1)

[Claims] In a charged particle beam lithography apparatus that draws on a substrate to be drawn, such as a wafer, having an orientation flat or an alignment mark while continuously moving a sample stage, the direction of the orientation flat of the substrate on the sample stage or a predetermined detecting means for detecting the direction of at least two alignment marks, and an offset amount between the coordinate value of a predetermined alignment mark and the coordinate value of the mark based on design data; A moving direction command means for moving the sample stage, and a correction means for correcting the coordinate values of the pattern according to the design data based on the direction detected by the detection means and the offset amount, and the sample stage is moved to the substrate. 1. A charged particle beam lithography device characterized in that the charged particle beam lithography device performs lithography while moving in a direction that substantially coincides with the direction of an orientation flat or the direction of an alignment mark.