JP3049226B2 - Glow discharge emission spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glow discharge emission spectrometer for analyzing generated light with a spectroscope while sputtering a sample.

[0002]

2. Description of the Related Art When a DC or high-frequency high voltage is applied between two electrodes in an argon (Ar) atmosphere at a gas pressure of about 500 to 1300 Pa, a glow discharge occurs.
Ar ions are generated. The generated Ar ions are accelerated by a high electric field, collide with the surface of the cathode, and knock out substances existing there. This phenomenon is called sputtering, and the sputtered particles (atoms, molecules, and ions) are excited in the plasma and emit light having a wavelength specific to the element when returning to the ground state. An analysis method in which the emitted light is separated by a spectroscope to identify elements is called a glow discharge emission spectral analysis method. There is an increasing demand for analyzing a desired part of an analysis surface by using an analyzer embodying the glow discharge emission spectroscopic analysis method, for example, for so-called mapping analysis (distribution analysis) using a semiconductor wafer as a sample.

[0003]

However, in the conventional apparatus, positioning of the sample is not automated, and an operator manually supports the glow discharge tube so that a desired portion of the sample faces the anode tube. The positioning was inaccurate and cumbersome without contacting the parts.

Accordingly, an object of the present invention is to provide a glow discharge optical emission spectrometer that automates the analysis of a desired portion of a substantially disk-shaped sample having a notch indicating the crystal orientation at the periphery. Things.

[0005]

According to a first aspect of the present invention, there is provided a glow discharge optical emission spectrometer, in which a sample is first brought into contact with an anode tube to which a voltage is applied to the sample. It includes a glow discharge tube having a support portion, and a decompression means for evacuating the inner space of the anode tube is accommodated, and a power supply means for generating a glow discharge by applying a voltage between the anode tube and the sample ing.

[0006] Then, for a substantially disk-shaped sample having a notch indicating the crystal orientation at the periphery, the positions of the notch and the center of the placed sample are calculated, and based on those positions, An orientation flat aligner is provided for setting the center of the sample at a predetermined transfer position and setting the desired direction of the sample to the predetermined transfer direction. Further, the sample is moved between the storage position where the sample is stored, the orientation flat aligner, and the analysis position facing the anode tube, and a desired portion of the analysis surface of the sample is positioned at the analysis position. to, receive samples set to the predetermined transfer position and transfer direction from the orientation flat alignment device, said toward the desired direction in the analysis position by moving the sample while maintaining at least parallel to, the
Analyzing a sample with the desired site located at the analysis position
A robot device for holding a surface in contact with the support portion.
I have .

According to the first aspect of the present invention, even when the center of the sample is displaced from the center of rotation of the orientation flat aligner, the orientation flat aligner corrects the shift and shifts the desired direction of the sample to the robot apparatus. Is set to a predetermined delivery direction, and the robot device receives the sample and transfers it to the analysis position, while maintaining the desired direction at least parallel to the analysis position so that the desired portion is located at the analysis position. By moving the sample as it is, the analysis surface of the sample can be held in contact with the support of the glow discharge tube. In other words, even if the center of the sample is displaced from the center of rotation of the orientation flat aligner, the analysis of the desired portion of the sample can be automatically automated.

Further, the robot device only needs to move the sample while maintaining the desired direction set by the orientation flat aligner at least parallel to the analysis position, and it is not necessary to adjust the direction of the sample. Control of the robot device is easy. Furthermore, since the robot device moves the sample between the storage position, the orientation flat aligner and the analysis position,
Can be automated for sequential analysis of multiple samples. Moreover, since existing orientation flattening machines and robot devices can be used, the devices can be easily configured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A glow discharge optical emission spectrometer according to one embodiment of the present invention will be described below with reference to the drawings.
First, the configuration of this device will be described. In this apparatus, as shown in FIG. 2, light S emitted from a grim glow discharge tube 1 that generates light having a wavelength specific to an element by sputtering using a glow discharge and transmitted through a window plate 13 is spectrally separated. Incident on the vessel 22. The spectroscope 22 includes an entrance slit 24, a diffraction grating 26 that diffracts the light S incident from the entrance slit 24 at different diffraction angles according to the wavelength,
An output slit 27 for passing the diffracted light and a photomultiplier tube 28 for measuring the intensity of the diffracted light are provided.

[0010] This device is used as a glow discharge tube.
A hollow anode type grim glow discharge tube 1 as shown in FIG. 3 is used. In the grim glow discharge tube 1, a support block (a support portion to which the sample 6 is brought into contact, which is also an insulating portion in the present embodiment) 2 and an anode block 3 form a sealing member 11 such as an O-ring. Are joined through. The anode block 3 is integrally formed with a hollow anode tube 3d. The anode tube 3d is inserted into the support block 2 and is close to the analysis surface (surface) 6a of the sample 6. Here, the sample 6 is substantially disc-shaped, such as a semiconductor wafer, having a notch (orientation flat, notch, etc.) 6b (FIG. 1) indicating the crystal orientation at the periphery. This sample 6 is pressed against the support block 2 by the cathode block 4 mainly in an airtight manner via a sealing member 11 such as an O-ring formed in an annular shape surrounding a portion to be analyzed on the analysis surface 6a.

Thus, the inner space (glow discharge space) of the support block 2 for accommodating the hollow anode tube 3d by the sample 6.
The opening of V is sealed, and the inner space V is evacuated from the first and second evacuation holes 3b and 3c by an evacuation device (decompression means) not shown. Further, the anode block 3 has an argon gas supply hole 3a, and the tube V has a rare gas atmosphere of argon (500 to
1300 Pa).

The grim glow discharge tube 1 has a power supply (power supply means) 12 between the anode block 3 and the cathode block 4.
A high voltage is applied to generate a glow discharge, a negative voltage is applied to the sample 6 through the cathode block 4, and cations of argon generated by the generation of the glow discharge collide with the analysis surface 6a of the sample. The sample 6 is sputtered. The sample 6 and the hollow anode tube 3d are cooled through the cathode block 4 by introducing the coolant into the jacket from a coolant introduction passage (not shown) of the cathode block 4 and feeding the coolant to the coolant discharge passage. I have.

Further, the apparatus has a so-called robot device for holding the sample 6 in a state where the analysis surface 6a of the sample is in contact with the support block 2, and the robot device includes a first robot hand 14 (FIG. 1). And the second robot hand 15. The second robot hand 15 is an anode tube 3d
, The cathode block 4 is gripped and moved up and down. As shown in the plan view of FIG. 1, the first robot hand 14 includes a base 14a, a first axis 14b that moves up and down (perpendicular to the paper surface) and rotates with respect to the base 14a, and a first axis 14b. A first arm 14c having an end fixed thereto, a second shaft 14d rotating with respect to a distal end of the first arm 14c, a second arm 14e having a base end fixed to the second shaft 14d, and a distal end of the second arm 14e. On the other hand, it comprises a rotating third shaft 14f, a third arm 14g having a base end fixed to the third shaft 14f, and a hand portion 14h provided at the distal end of the third arm 14g for mounting the sample 6 thereon.

Further, the apparatus calculates the positions of the notch 6b and the center 6c of the placed sample, and sets the center 6c of the sample at a predetermined delivery position P based on those positions. Further, a so-called orientation flat aligner 19 for setting a desired direction 6d of the sample to a predetermined delivery direction L is provided. The orientation flat aligner 19 includes, for example, an XY table 19a and a rotary table 19b provided thereon and on which the sample 6 is placed. And the first robot hand 1
Reference numeral 4 denotes a storage position where the sample 6 is stored in a cassette 20 described later, an orientation flat aligner 19, and an anode tube 3
The sample is set in the predetermined delivery position P and the delivery direction L such that the sample is moved between the analysis position O and the analysis position O facing the sample d, and the desired portion of the analysis surface 6a of the sample is located at the analysis position O. 6 from the orientation flat aligner 19,
The sample 6 is moved while keeping the desired direction 6d at least parallel to the analysis position O.

Next, the operation of this device will be described.
First, on the inside of the side other than the side opened to face the first robot hand 14, the shelf plate 20a on which the sample 6 is placed is set.
A large number of samples 6 with the analysis surface 6a facing upward are accommodated in a substantially box-shaped cassette 20 having a large number of in the vertical direction (the direction perpendicular to the paper surface). Now, for example, for the uppermost sample 6, there are several desired portions to be analyzed in the direction of the orientation flat 6b (direction from the center 6c of the sample so as to be orthogonal to the orientation flat 6b). It shall be. When the effect is input to the apparatus from input means (not shown), the first robot hand 14 moves the uppermost sample 6 to be analyzed from the cassette 20 which is the storage position.
It is placed on the hand unit 14h and moved, and placed on the turntable 19b of the orientation flat aligner 19.

At this time, the first robot hand
The desired direction 6d of the sample, that is, the direction of the orientation flat 6b of the sample in this case, does not match the predetermined delivery direction L connecting the rotation center N of the shaft 14b and the rotation center 19c of the rotary table in the initial state. The center 6c of the sample is accurately positioned at a predetermined delivery position P at a predetermined distance from the rotation center N of the first axis of the first robot hand in the predetermined delivery direction L, that is, at the rotation center 19c of the rotary table in the initial state. They do not always match.

Then, the orientation flat aligner 19 rotates the rotary table 19b one rotation, and cuts the mounted sample based on the change in the intensity of light incident on the optical sensor 19d provided to face the periphery of the sample 6. The position of the notch 6b and the center 6c (the position with respect to the predetermined delivery position P) is calculated. Then, based on those calculated positions, the orientation flat aligner 19 sets the center 6c of the sample at the predetermined delivery position P, and sets the desired direction 6d of the sample as the predetermined delivery direction L.

Here, when there is no deviation between the calculated position of the center 6c of the sample and the predetermined delivery position P,
When the robot hand 14 places the sample 6 such that the center 6c of the sample accurately matches the center of rotation 19c of the rotary table in the initial state, the orientation flat aligner 19 rotates the rotary table 19b, Desired direction of sample 6d
Need only be set in the predetermined delivery direction L. The orientation flat aligner 19 of FIG. 1 is in this case, and shows a state when the desired direction 6d is the direction of the orientation flat 6b of the sample. Note that the tip of the desired direction 6d (the peripheral side of the sample 6) is set to face the opposite side (the left side in FIG. 1) of the first robot hand 14 in the predetermined transfer direction L.

On the other hand, when there is a deviation between the calculated position of the center 6c of the sample and the predetermined delivery position P, that is, the first robot hand 14 moves the sample to a position shifted from the rotation center 19c of the rotary table in the initial state. When the sample 6 is placed so that the center 6c comes, the orientation flat aligner 19
The rotation of the rotary table 19b and the parallel movement of the XY table 19a set the center 6c of the sample at a predetermined transfer position P and set the desired direction 6d of the sample to a predetermined transfer direction L. In this case, the rotation amount of the rotary table 19b of the orientation flat machine 19 and the parallel movement amount of the XY table 19a are uniquely determined, and either the rotation or the parallel movement may be performed first or may be performed simultaneously.

Next, the first robot hand 14 applies the sample 6 set at the predetermined transfer position P and transfer direction L as described above to the rotary table 19 of the orientation flat aligner.
b to the hand unit 14h, and a desired portion of the analysis surface 6a of the sample (for example, the center 6c of the sample in this case) is placed on the anode tube 3
While maintaining the desired direction 6d (eg, the direction of the sample orientation flat 6b) toward the analysis position O so as to be located at the analysis position O opposite to the analysis position O, that is, the first axis 14b of the first robot hand The sample 6 is moved in a straight line while matching a predetermined analysis carrying direction M connecting the rotation center N and the analysis position O. And the first robot hand 14
With the desired portion 6c of the analysis surface 6a of the sample positioned at the analysis position O, the analysis surface 6a of the sample is brought into horizontal contact with the support block 2 of the glow discharge tube 1 from below (the state shown in the upper right of FIG. 1). ).

It should be noted that maintaining the desired direction 6d toward the analysis position O does not mean that the sample 6 is maintained immediately after receiving the sample 6 from the orientation flat aligner 19. May be rotated,
After receiving, the desired direction 6d is directed to the analysis position O,
This means that the analysis surface 6a of the sample is maintained when it is moved to make it contact the support block (support portion) 2. Further, in the present invention, it is not always necessary to direct the desired direction of the sample to the analysis position after receiving it, and to move the sample straight while maintaining the state. That is, it suffices that the desired direction of the sample as a result of the movement is parallel to the desired direction of the moving sample. In the present invention, a sample set at a predetermined delivery position and delivery direction is received from the orientation flat aligner so that a desired portion of the analysis surface of the sample is located at the analysis position, and at least the desired direction is directed toward the analysis position. Moving the sample while keeping it parallel means that.

Further, as shown in FIG. 3, the second robot hand 15 holding the cathode block 4 rises, presses the cathode block 4 against the back surface 6e of the sample from below to make conductive contact, and holds the sample 6. At this time, as shown in FIG. 1, the hand portion 14h of the first robot hand is formed in a shape that does not interfere with the cathode block 4 (FIG. 3).

After that, the first robot hand 14 returns to the initial state as shown in FIG. 1 and stands by, for example, to avoid the application of the next high voltage. The hand unit 14h
Is made of ceramics or the like and the insulation is sufficient, the first robot hand 14 may be in a posture in which the analysis surface 6a of the sample is kept in contact with the support block 2 from below. In this case, the sample can be brought into contact with and held on the support block 2 by the first robot hand 14 alone. As shown in FIG. 3, the cathode block 4 has a three-stage structure in which the middle portion is made of an insulator and the upper and lower portions are made of a conductor (metal), and a power supply portion (feeding means) 12 is provided in the upper portion. Since the second robot hand 15 grips the lower part from the middle portion while conducting, the second robot hand 15 is not likely to receive a high voltage.

Thus, according to the apparatus of the present embodiment,
The center 6c of the sample in FIG. 1 is the rotation center 1 of the orientation flat aligner.
9c, the orientation flat aligner 19 sets the desired direction 6d of the sample to the predetermined transfer direction L to the first robot hand 14 while correcting the shift, and
The robot hand 14 receives the sample 6 and transfers the sample 6 to the analysis position O, and moves the desired direction 6 d so that the center 6 c of the sample is located at the analysis position O.
The specimen 6 is moved while being kept at least parallel to, the analytical surface 6a of the specimen is brought into contact with the support block 2 of the glow discharge tube 1, and the state is maintained by the second robot hand 15 (FIG. 3). be able to. That is, even if the center 6c of the sample is displaced from the rotation center 19c of the orientation flat aligner, the analysis of a desired portion of the sample 6 can be automatically automated.

The first robot hand 14 may move the sample 6 while maintaining the desired direction 6d set by the orientation flat aligner 19 at least parallel to the analysis position O. Therefore, the control of the first robot hand 14 is easy. Moreover, since the orientation flat aligner 19 can use an existing one, the apparatus can be easily configured.

In this embodiment, the analysis surface 6a of the sample is brought into contact with the support block 2 with the first robot hand 14 in a state where the desired portion 6c of the analysis surface 6a of the sample is located at the analysis position O. After that, the cathode block 4 was pressed from below by the second robot hand 15 in FIG. 3 to hold the sample 6, but the present invention is not limited to such a procedure.
With the first robot hand 14 of FIG. 1, in a state where a desired portion 6 c of the analysis surface 6 a of the sample is located immediately below the analysis position O,
After placing the sample 6a on the cathode block 4 held by the second robot hand 15 in FIG. 3 waiting just below the analysis position O, the second robot hand 15 is raised to move the analysis surface 6a of the sample. The sample 6 can also be held in contact with the support block 2.

As described above, the analysis surface 6a of the sample is not only held in contact with the support block 2 by the first and second robot hands 14 (FIG. 1) and 15 but also supported by a pressure reducing means (not shown). The inner space V of the block 2 is evacuated to a rare gas atmosphere of argon (500 to 1300 P).
In the case of a), the sample is pressed against the support block 2 via the seal member 11 even by the atmospheric pressure applied to the back surface 6e of the sample, and is brought into close contact therewith.

Then, the anode block 3 and the cathode block 4
When a high voltage of several hundreds to several thousand volts is applied between the anode tube 3d and the sample 6 by the power supply unit (power supply means) 12, glow discharge is generated, and cations of argon are generated. The sample 6 is sputtered by the Ar ions, and the generated light S passes through the window plate 13 and travels through the entrance slit 24 of FIG. 2 to the diffraction grating 26 of the spectroscope 22. The diffraction grating 26 diffracts light of a predetermined wavelength,
The light enters the photomultiplier tube 28 through the exit slit 27. The photomultiplier tube 28 measures the intensity of the incident light. That is, a desired portion of the sample 6 is analyzed, for example, the center 6c of the sample in FIG.

Next, in order to analyze another desired part in the same desired direction 6d, the first robot hand 14 returns to the posture in which the analysis surface 6a of the sample is brought into contact with the support block 2, and the pressure is reduced. When the pressure in the inner space V of the support block 2 in FIG. 3 is released by the means and the second robot 15 holding the cathode block 4 descends, the sample 6 is moved to the hand section 14h in FIG.
Placed as originally. Therefore, the first robot hand 14 maintains the desired direction 6d (for example, the direction of the sample orientation flat 6b in this case) toward the analysis position O so that the next desired part to be analyzed is located at the analysis position O. In this state, that is, the sample 6 is moved straight while matching the predetermined analysis carrying direction M, and the analysis surface 6a of the sample is brought into horizontal contact with the support block 2 in a state where a desired portion is located at the analysis position O. Then, the second robot hand 15 (FIG. 3)
This state is maintained. The subsequent analysis procedure is the same as described above.

In order to analyze a desired portion of the same sample 6 in another desired direction 6d, after the previous analysis is completed, the sample 6 placed on the hand unit 14h is moved to the first robot hand 14h.
Is moved from the analysis position O and is mounted again on the rotary table 19b of the orientation flat aligner 19. Then, in the same manner as described above, the orientation flat aligner 19 moves the center 6c of the sample.
Is set to a predetermined delivery position P, and a new desired direction 6d of the sample is set to a predetermined delivery direction L. The subsequent procedure is the same as described above.

When the analysis of the sample 6 is completed, the first robot hand 14 places the sample 6 on the hand section 14h from the analysis position O and moves the same to the cassette 20 at the storage position. On the shelf plate 20a. When performing analysis on another sample 6, the above procedure is repeated. As described above, according to the apparatus of the present embodiment, the first robot hand 14 controls the cassette 2 in which the sample 6 is stored at the storage position.
Since it is moved between 0 and the orientation flat aligner 19 and the analysis position O, continuous analysis of a plurality of samples 6 can be automated. Moreover, not only the orientation flat aligner 19 but also the first
Robot hand 14, second robot hand 15 (FIG. 3)
Also, since an existing device can be used, the device can be easily configured.

[0032]

As described above, according to the glow discharge optical emission spectrometer of the present invention, even if the center of the sample is displaced from the rotation center of the orientation flat aligner, the orientation flat alignment machine is not displaced. While correcting, the desired direction of the sample is set to a predetermined transfer direction to the robot device, and the robot device transfers the sample to the analysis position while transferring the sample to the analysis position, so that the desired portion is located at the analysis position. By moving the sample while keeping the direction at least parallel to the analysis position, the analysis surface of the sample can be held in contact with the support of the glow discharge tube. In other words, even if the center of the sample is displaced from the center of rotation of the orientation flat aligner, the analysis of the desired portion of the sample can be automatically automated.

Further, the robot device may move the sample while maintaining the desired direction set by the orientation flat aligner at least in parallel to the analysis position, and there is no need to adjust the direction of the sample. Control of the robot device is easy. Furthermore, since the robot device moves the sample between the storage position, the orientation flat aligner and the analysis position,
Can be automated for sequential analysis of multiple samples. Moreover, since existing orientation flattening machines and robot devices can be used, the devices can be easily configured.

[Brief description of the drawings]

FIG. 1 is a plan view showing a glow discharge optical emission spectrometer according to an embodiment of the present invention.

FIG. 2 is a front view showing a spectroscope of the analyzer according to the first embodiment.

FIG. 3 is a longitudinal sectional view showing a glow discharge tube of the analyzer according to the first embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glow discharge tube, 2 ... Support part (support block), 3d
... Anode tube, 6 ... Sample, 6a ... Sample analysis surface, 6b ... Sample notch, 6c ... Sample center, 6d ... Sample desired direction, 12 ... Power supply means, 14, 15 ... Robot device (No. 1, second robot hand), 19 ...
20: storage position (cassette), L: predetermined delivery direction,
O: analysis position, P: predetermined delivery position, V: inner space.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-261937 (JP, A) JP-A-4-154146 (JP, A) JP-A-6-43100 (JP, A) JP-A-5- 113402 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 21/00-21/01 G01N 21/17-21/74 G01N 1/00 101 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. A glow discharge tube having an anode tube to which a voltage is applied to a sample and a support portion to which the sample comes in contact, and a pressure reducing means for evacuating an inner space in which the anode tube is housed. , a glow discharge emission spectroscopic analysis apparatus and a power supply means for applying a voltage to generate the glow discharge between the anode tube and the sample, the sample, a notch indicating the crystal orientation in the peripheral portion The position of the notch and the center of the placed sample is calculated, the center of the sample is set to a predetermined delivery position based on those positions, and and orientation flat alignment machine to set a desired direction in a predetermined transfer direction, the specimen, and storage position in which the sample is stored, and the orientation flat alignment device moves between an analysis position opposing the anode tube, Also, a desired part of the analysis surface of the sample is located at the analysis position. As location, it receives a sample set to the predetermined transfer position and transfer direction from the orientation flat alignment device, toward the desired direction in the analysis location by moving the sample while maintaining at least parallel to, the desired Part
Support the analysis surface of the sample in the state where it is located at the analysis position
A glow discharge optical emission spectrometer comprising a robot device which is held in contact with a part . 2. An anode block according to claim 1, wherein said support portion is an insulating portion, and said glow discharge tube has said anode tube.
And a support unit and a cathode block, wherein the robot apparatus moves a sample.
The cathode block and the cathode block, and
Consists of a second robot hand that presses against the contacted sample
And a hand portion of the first robot hand on which a sample is placed
Is pressed by the sample while being held by the second robot hand.
Formed so as not to interfere with the cathode block
Glow discharge emission spectrometer.