JP2981983B2 - Pattern film repair device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a semiconductor integrated circuit.
Or a mask used in the semiconductor integrated circuit manufacturing process or
When correcting the pattern film on the reticle,
It relates to a removing device. The present invention relates to a method for focusing a focused ion beam on a sample.
And irradiate the sample to perform micro-processing of minute portions on the sample surface.
Source for generating an ion beam for the purpose of
A scanning electrode for scanning the focused ion beam; and
Scanning control circuit and irradiating the focused ion beam
To detect secondary charged particles generated from the sample
To the output of the secondary charged particle detector and the secondary charged particle detector
A display device that displays a pattern on the sample in response to the
A pattern film correcting apparatus,
When irradiating the focused ion beam to a place,
Activated by the on-beam and reacts to the film material of the pattern.
Before etching gas with a chemical etching action
Nozzles that spray locally at predetermined locations in the pattern
Focused ion beam for scanning and irradiating the sample
Set a certain period of time before moving to the adjacent spot
This minimizes the amount of etching gas introduced into the equipment.
Is it possible to quickly remove a predetermined part of the pattern film while minimizing it?
It brings out the effect of performing cleanly to a minimum. [0003] 2. Description of the Related Art A conventional pattern film repair apparatus is shown in FIG.
You. The ions generated from the ion source 1 are
By passing through the ion optical system of the objective lens 3, a predetermined half
Focused ion beam 5 with a diameter (1μ or less) and scanning
The surface of the sample 6 is scanned by passing through the electrode 4. Trial
Data set in advance at predetermined locations of the pattern film on the surface of the material 6
To move the XY stage 7 directly below the focused ion beam
Or further scanning a focused ion beam 5
Charged particles emitted from the surface of the sample 6 by the irradiation of
8 is detected by the secondary charged particle detector 9 and the A / D converter
After detecting the secondary charged particles on the display device 11 through an electronic circuit such as 10.
Display the pattern and observe the pattern film visually
Then, on the XY stage 7, within the focused ion beam scanning range
A predetermined portion of the pattern film to be removed
The sample 6 is moved to. The position of a predetermined portion of the pattern film to be removed
Set the position and range, scan electrode 4 and / or blankin
The scanning range of the focused ion beam is set by the scanning electrode 12.
The focused ion beam 5 is applied only to a predetermined location on the surface of the sample 6.
Irradiate to scan. Thus, the pattern film
Focused ion beam is repeatedly irradiated to only the spot by scanning
Therefore, the pattern film of the predetermined portion is formed by ions.
Removed by sputtering (sputter etch)
You. FIG. 4 shows a focused ion beam according to the prior art.
FIG. 3 is a diagram showing a scanning irradiation order. Focusing A for Fixing 24
Focused ion beam irradiation with on-beam scanning range
Are spot numbers 1, 2, 3,..., I-1, i,.
Scans one frame in the order of
Repeat the frame. In addition, at a predetermined time for each spot
The inter-focused ion beam stops. Usually the spot interval is
It is smaller than the full width of the focused ion beam. Also, some sports
Time to move from one spot to the next adjacent spot is instantaneous
The raster scan is continuous as a whole.
Have been done. 4 from spot 1 to i-1 in FIG.
Fig. 5 shows the distribution of focused ion beam irradiation intensity
Show. .., I-1 in FIG.
2, ..., i-1. In FIG.
When the focused ion beam is irradiated to the pots 1, 2, and 3
The distribution of the ion beam irradiation area is
, Are supported. As can be seen from FIG.
,... Have overlapping parts. [0006] SUMMARY OF THE INVENTION Conventional pattern film correction
In the method and the apparatus, the removal of a predetermined portion of the pattern film is focused on.
On-beam sputtering (sputter etching
G), the pattern film was completely removed
It takes a very long time to complete
The pattern formed on the plate 14 is sputter etched
And the material of the pattern film 10 is
Sputter deposited on the surrounding area or its surrounding area
It becomes object 13 and the cut of sputter etch only gets worse
And the removal speed was even slower. [0007] The present invention solves the above problems.
Create an ion beam with a solution
An ion source and a scanning electrode for scanning the focused ion beam.
A pole and scanning control circuit, and irradiating the focused ion beam.
Charging to detect secondary charged particles generated by
A particle detector according to the output of the secondary charged particle detector
A pattern comprising a display device for displaying a pattern on the sample;
In the membrane correction device, a predetermined portion of the pattern
When irradiating the focused ion beam, the focused ion beam
Activated by the
Etching gas that has a chemical etching effect
Nozzles that spray locally at predetermined locations on the
The focused ion beam that scans and irradiates the sample is adjacent
More than a certain amount of time before moving to a spot
Patent application title: Pattern film repair method and device
You. [0008] The operation of the above structure is concentrated at a predetermined position of the pattern film.
The ion beam is repeatedly scanned, and the film at that part is
It is gradually removed by sputter etching.
Activated by ion beam for pattern material
And an etching gas with a chemical etching effect blows.
The removal process of the pattern removal unit is
It is speeded up. Also, the sputter etched pattern
The reactant reacts with the etching gas and again as shown in FIG.
No sputter deposition occurs. Still further, locally at a predetermined portion of the pattern
Providing a nozzle for spraying and scanning and irradiating the sample
While the focused ion beam moves to an adjacent spot
After a certain period of time or more,
Etching gas while minimizing the amount of etching gas
To maximize the effects of chemical reactions
The vacuum inside the device does not deteriorate,
There is no need to provide a ventilation device. [0010] DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.
I do. FIG. 1 shows the entire pattern film repair apparatus according to the present invention.
FIG. Extraction electrode from ion source 1 (Figure
(Not shown) is focused by a focusing lens
2 and the objective lens 3
A focused ion beam 5 having a long diameter on the surface of the sample 6
Irradiate. In addition, the focused ion beam
Irradiation while scanning the beam 5 on the surface of the sample
For this purpose, a scanning electrode 4 is provided. Scanning electrode 4
Is a scanning control for controlling the scanning of the focused ion beam 5
It is controlled by the circuit 16. Sample 6 holds Sample 6
XY stage to move on the XY plane
It is placed. At the irradiation position of the focused ion beam 5 on the sample,
The device for spraying the etching gas is supplied from the gas supply source 21.
Nozzle that blows the etching gas on the surface of the sample
19 and a bar for turning on / off the etching gas
A lube 20 is provided. For irradiation of focused ion beam 5
The secondary charged particles 8 generated from the surface of the sample 6 are
6 Detected by the secondary charged particle detector 9 directed to the surface
It is. Further, the signal from the secondary charged particle detector 9 is A
It is taken into the arithmetic circuit 15 through the / D converter 10. Performance
The arithmetic circuit 15 also takes in the signal of the scan control circuit 16 and loads the secondary load.
The signal from the particle detector 9 and the signal from the scanning circuit 16 are
By synchronizing, the pattern shape can be
Is displayed as an image. The irradiation path of the focused ion beam
Bead so that the focused ion beam 5 does not irradiate the sample 6
The blanking electrode 12 for deflecting the system greatly
Have been. The blanking electrode 12 is a blanking circuit
17 turns ON / OFF the blanking voltage.
You. The scanning range setting unit 18 scans only a predetermined portion of the surface of the sample 6
Focused ion beam for irradiation with focused ion beam 5
This is for setting the scanning range. Running a focused ion beam
The scanning irradiation range is controlled by the scanning set by the scanning range setting unit 18.
Depending on the scanning range, the focused ion beam
And / or achieved by controlling the scan control circuit 16. Next, the process of correcting the pattern film will be described.
The inside is maintained in a vacuum by a vacuum pump (not shown)
Pattern to be corrected in a chamber (not shown)
Is inserted. Here, sample 6 is glass
Or chrome or aluminum on a substrate such as silicon
Are formed. And amendments
By inputting the position data of the place, the sample 6 can be corrected.
The point to be located is approximately at the center of the scanning range of the focused ion beam 5.
The XY stage 7 is driven as described above. Here, focusing
The surface of the sample 6 is scanned and irradiated with the on-beam 5 to
The secondary charged particles 8 generated are detected by the secondary charged particle detector 9.
The shape of the pattern formed on the surface of the sample 6
The image is displayed on the image display device 11. Image of the location of the correction is displayed
If the display on the device 11 is at the edge or off
Drive the XY stage 7 again to focus
It is set to be substantially at the center of the scanning range of the on-beam 5. Picture
The pattern to be corrected is displayed at the approximate center of the display of the image display device 11.
Is entered, enter the pattern correction range in the scan range setting 18.
And the scanning range setting part 18
The scanning electrode following the ranking electrode 12 and the scanning control circuit 16
4 to output a signal. The pattern film correction is focused
Repeat the on-beam 5 only on the part to be corrected on the sample 6.
This is performed by performing scanning irradiation. Also, when correcting the pattern film, etching is required.
The valve 20 is opened by a signal from the gas control circuit 23,
The nozzle 19 is brought close to the sample surface by the air cylinder 22.
You. The etching gas 24 is supplied to the sample 6
It is sprayed locally on the modified part of the turn. Etchin
The gas 24 varies depending on the material of the pattern film and the material of the container.
Are, for example, chlorine gas and halogen fluoride gas. Here, the chemical reaction by the etching gas
Indicates that the etching gas molecules attached to the surface of the sample 6 are focused.
It is caused by activation by on-beam irradiation. Immediately
That is, when the focused ion beam is irradiated on the surface of the sample 6,
On the on-beam irradiation spot, the attached etching
The gas molecule density must be required and sufficient.
On the other hand, the flow rate of the etching gas introduced into the
Source, secondary charged particle detector, vacuum pump, etc.
Must be kept to a minimum. Furthermore, etching
If gas flow is too high, focused ion beam and etching
The gas molecules collide and scatter before reaching the surface of the sample 6, and the sample
6 except for the position to be corrected is etched.
The focused ion beam scanning method according to the present invention is implemented in an apparatus.
Etching while minimizing the amount of etching gas entering
It maximizes the effect of the chemical reaction caused by gas.
You. One of the focused ion beam scanning irradiation methods according to the present invention
In the embodiment, the ion beam irradiation order described with reference to FIG.
Focused ion beam moves to adjacent spots while following
In the meantime, blanking by signal from blanking circuit
A blanking voltage was applied to the electrode 12 for a certain period of time to obtain a sample 6.
A state where the focused ion beam is not irradiated thereon is set. FIG. 6 shows focused ion beam scanning according to the present invention.
FIG. 6 is a diagram showing a change over time of a blanking voltage during irradiation,
Focused ion beam irradiation state at sinking voltage H1, focusing at L0
The ion beam irradiation is stopped. Blanking voltage L0
After irradiating the sample with the focused ion beam for a certain time,
King voltage becomes H1 and stops ion beam irradiation for a certain period of time
And then move to the next spot to get the blanking voltage
Return to L0 and perform focused ion beam irradiation for a certain period of time.
repeat. Here, blanking voltage L0 time and H1 time
The interval is set independently. Blanking voltage LO time and
The H1 time is about 1 to several hundred μsec. Neighboring spots
The focused ion beam provided while moving to
Meaning of no time (called spot blanking time)
Is as follows. Focused ion beam described in FIG.
Irradiation as described in FIG.
The overlapping part of the distribution
Etching gas molecules adhere, and the next focused ion beam irradiation
It contributes to the chemical reaction during firing. That is, focusing
A fixed time to set between the on-beams moving to adjacent spots
The above time is defined as the etching gas at the overlapping part of the irradiation distribution.
Until the molecules adhere to the amount required for the chemical reaction to occur.
It's time for If the spot blanking time is
If the etching gas flow rate is not significantly increased,
The shortage of the etching gas occurs at the corner. Next, the focused ion beam scanning illumination according to the present invention will be described.
A second embodiment of the shooting method will be described with reference to FIG.
You. FIG. 7 shows a focused ion beam apparatus range for correction.
Box 24 is equivalent to that shown in FIG._1,a_2,...
a_i-1,a_i... a_k,b_1,b_2,..., b_i-1,b_i...
b_k,c_1,c_2,..., c_i-1,c_i... c_k,d_1,d_2,・
.., d_i-1,d_i.. d_k,Each focussed ion beams
The irradiation spot is shown. In a second embodiment, a focused ion
In FIG._1,a_2,..., a_{i- 1,}a
_i... a_k,b_1,b_2,..., b_i-1,b_i... b_k,c_1,
c_2,..., c_i-1,c_i... c_k,d_1,d_2,..., d
_i-1,d_i... d_k,And finish one frame
Then, the correction is repeatedly performed in this frame. This focused ion beam scanning irradiation method is a scanning
The scanning voltage applied to the scanning electrode 4 is controlled by the scanning control circuit 16.
I'm going. This focused ion beam scanning irradiation
The method is to use spots adjacent to a spot (eg, spot
Spot b for d1_1,c _1,c_2,b_i) Focused ion
During the beam irradiation, a time longer than the fixed time elapses
Etching on the surface of the sample 6
The gas molecule density is in a necessary and sufficient state. Also
This focused ion beam scanning irradiation method uses a certain focused ion beam.
Beam irradiation spot and the next focused ion beam irradiation spot
Between the irradiation distributions shown in Fig. 5
Etching on the surface of sample 6
The gas molecular density is always necessary and sufficient.
In other words, one focused ion beam irradiation spot and the next focused ion beam
Overlap between the irradiation distribution and the on-beam irradiation spot
If there is only a distance that can not be separated, the chemical reaction of etching
Is more efficient. Focused ion beam irradiation according to the present invention
With the scanning method, the prior art focused ion beam irradiation
Correct pattern film using etching gas by scanning method
Required and sufficient amount of sample 6
Install in the equipment necessary to obtain the density
The total flow rate of the etching gas can be less than one digit
You. The sample is a photomask or IC
It is a product circuit itself. [0018] The removal processing of the pattern removal section is speed
Will be Also, the sputter-etched pattern material
Reacts with the etching gas and resputters as shown in FIG.
No evaporation is performed. Or even the pattern
A nozzle for spraying locally at a fixed location is provided, and
An adjacent scan of the focused ion beam for scanning and irradiating a workpiece.
By providing more than a certain time between pots,
While minimizing the amount of etching gas introduced into the
Maximize the effects of chemical reactions caused by the etching gas
Without deteriorating the vacuum inside the device,
There is no need to provide a special exhaust device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing an entire pattern film repair apparatus. FIG. 2 is an overall configuration diagram of a conventional device. FIG. 3 is a cross-sectional view of a sample showing a defect of the conventional device. FIG. 4 is a plan view showing a focused ion beam scanning irradiation order. FIG. 5 is a view showing a focused ion beam irradiation intensity distribution in a line from spot 1 to i-1 in FIG. 4; FIG. 6 is a diagram showing a change over time of a blanking voltage during focused ion beam scanning irradiation according to the present invention. FIG. 7 is a plan view showing a focused ion beam scanning irradiation sequence based on Embodiment 2 of the present invention. [Description of Signs] 1 Ion source 2 Focusing lens 4 Scanning electrode 5 Focused ion beam 6 Sample 9 Secondary charged particle detector 11 Display device 16 Scan control circuit 19 Nozzle

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03F 1/00-1/16 H01L 21/30-21/308

Claims (1)

(57) [Claims] An ion source that generates an ion beam, an ion lens that focuses the ion beam and turns it into a focused ion beam, a scan electrode that scans the focused ion beam, and a scan control circuit that outputs a signal that controls the scan electrode. ,
A secondary charged particle detector for detecting secondary charged particles generated from the sample by irradiating the sample with the focused ion beam, and displaying a pattern on the sample in accordance with an output of the secondary charged particle detector When the focused ion beam is irradiated to a predetermined portion of the pattern to remove the pattern film, the display device is activated by the focused ion beam and chemically etches the film material of the pattern. A nozzle that locally blows an etching gas onto a predetermined location of the pattern, and the focused ion beam that scans and irradiates the predetermined location with each other within the predetermined location.
Means for providing a time during which the focused ion beam is not irradiated for a predetermined time or more while moving to adjacent spots having an irradiation distribution having an overlapping portion . 2. An ion source that generates an ion beam, an ion lens that focuses the ion beam and turns it into a focused ion beam, a scan electrode that scans the focused ion beam, and a scan control circuit that outputs a signal that controls the scan electrode. ,
A secondary charged particle detector for detecting secondary charged particles generated from the sample by irradiating the sample with the focused ion beam, and displaying a pattern on the sample in accordance with an output of the secondary charged particle detector When the focused ion beam is irradiated to a predetermined portion of the pattern to remove the pattern film, the display device is activated by the focused ion beam and chemically etches the film material of the pattern. A nozzle for spraying an etching gas locally on a predetermined portion of the pattern, and irradiating the focused ion beam to scan the predetermined portion, and irradiating adjacent spots to be irradiated in the predetermined portion when the predetermined portion is scanned. Overlapping distribution
For each spot having a focused ion beam irradiation spot, the irradiation spot located at a distance away from a certain focused ion beam irradiation spot where the overlapping portion of the irradiation part cannot be formed is used as the next focused ion beam irradiation spot, and etching is performed using the predetermined spot.
A pattern film correcting apparatus for removing a pattern film at a certain place .