JPH04103769A - Laser cvd device - Google Patents

Abstract

PURPOSE:To make a laser beam inlet glass window relatively thin and to miniaturize a chamber itself by setting one between the two shafts of an XY stage in the chamber and the other outside the chamber to move the entire chamber. CONSTITUTION:The chamber 14 of the CVD device is filled with a gaseous compd. 13, and a sample 15 is arranged in the chamber. A laser beam 17 introduced from a glass window 20 is condensed on the surface of the sample 15, and a conductive material is locally deposited close to the part irradiated with the laser beam by the thermal CVD action. The sample is scanned by the XY stages 18 and 19, and the deposits are successively connected in the horizontal direction to form a wiring. The X shaft of the XY stage 18 is arranged below the chamber 14 and the Y shaft of the XY stage 19 in the chamber 14. Accordingly, the entire surface of the sample 15 need not be covered by the window 20 provided in the upper wall of the chamber 14 in the X shaft stroke direction. Consequently, the window 20 can be made relatively thin while coping with a large-sized sample, the volume of the chamber 14 is reduced, and the device is also miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser CVD apparatus, and particularly to the structure of an XY stage and a chamber for scanning a sample.

[Conventional technology]

"In the CVD equipment, a glass window (made of a material that transmits laser light) is provided on the chamber wall to introduce laser light, which is an excitation source. Also, local deposition by laser CVD is used to deposit thin films. In a laser CVD apparatus intended for patterning, an XY stage is usually used as a means for scanning a sample with laser light.

In conventional laser CVD apparatuses, the following two methods have been adopted for the installation position of the XY stage.

(i) A type in which all the XY stages are installed inside a chamber (in a compound gas atmosphere) (referred to as a chamber internal type). For example, an example can be found in Japanese Patent Application No. 61-220158. Now, FIG. 3 shows the configuration of this conventional example. In FIG. 3, the XY stage 1 is all placed inside the chamber 2,
A glass window 3 is provided on the upper wall surface of the chamber 2 to introduce a laser beam serving as an excitation source. A sample 4 is placed below the glass window 3, and an objective lens 5 is placed above the glass window 3.

(ii) The entire chamber is moved by an XY stage; in this case, the XY stage is placed entirely outside the chamber (referred to as a chamber external type). Examples of this include reference (1) J, Vac, Sci, Technol, 85
゜496 (1987) (2> Appl, Phy
See, for example, S. Lett, 43°946 (1983). The configurations in these examples are shown in Figure 4 (A) ~
Shown in (C). In the figure, the entire XY stage 1 is installed outside the lower side of the chamber 2, and the entire chamber 2 is moved by the XY stage 1, and a sample 4 (B in the figure) is provided with an objective through a glass window 3. The laser beam is configured to be focused by a lens 5. Note that a guichroic mirror 6 is arranged above the objective lens 5, and in FIGS. 4(A) and 4(C), the laser beam from the laser 7 passes through an optical shutter 8 and a lens 9 before being It is configured to be guided by a loic mirror 6. Further, in FIG. 4(A), reference numeral 9a is a monitor, 9b is a computer, 9C is an interface, 37 is a reflected light illuminator,
38 is a transmitted light illuminator, 39 is a reflecting mirror, and 36 is a camera. In addition, in FIG. 4(C), 9d is a photodiode, 9e is a vidicon using the photoconductive effect,
9f is a monitor, 9g is a host combination coater, 9h is a control device, 41 is a light receiving section, 42 is an eyepiece, 43 is a light source,
44 indicates a control signal.

[Problem to be solved by the invention]

However, the above-mentioned conventional examples have the following problems, especially when handling large samples.

(1) Problem with the internal chamber type shown in FIG. 3 In this type, the entire XY stage 1 is installed within the chamber 2, so there is a drawback that the internal volume of the chamber 2 becomes larger than the space required for the process.

This is unavoidable because the projected floor area of the XY stage 1 requires about four times the area of the sample 4.

Furthermore, even when considering a 6-inch square stroke, a space of 30 to 401 mm is generated excluding the volume occupied by mechanical parts, but a 450M square LCD is expected to be used in the future.
When a glass substrate for a liquid crystal display (liquid crystal display) is considered as a sample, its volume reaches several hundred units. Therefore, when considering the evacuation time for replacing the internal atmosphere of the chamber 2, the amount of compound gas consumed, etc., it is clear that this is not a practical device configuration.

(ii) Problem with the external chamber type shown in FIGS. 4(A) to (C) In this case, although there is an advantage that the volume of the chamber 2 can be minimized, the plate of the glass window 3 attached to the wall of the chamber 2 The relationship between the thickness and the objective lens 5 becomes a problem. Normally, a vacuum exhaust system is used to replace the atmosphere after the sample 4 is placed in the chamber 2, so the glass window 3 must be thick enough not to be destroyed by a pressure difference of 1 atmosphere. However, as the area of the sample 4 increases and the area of the glass window 3 is expanded to cover it, the glass window 3 rapidly becomes thicker. For example, effective area 40
In the case of a glass window 3 with a width of 0, a glass plate with a thickness of more than 10 mm is required. On the other hand, it is technically difficult to maintain a working distance of 15 lenses or more with the objective lens 5 that can focus the laser beam to a diameter of several μm or less, and the device using the thick glass window 3 as described above is difficult to achieve. cannot be configured.

The purpose of the present invention is to solve two of the above-mentioned problems.It is possible to keep the thickness of the glass window relatively thin regardless of the external dimensions of the sample, and to reduce the chamber volume compared to the case of an internal chamber type. It is an object of the present invention to provide a laser CVD device which can be made small and the device can also be made small.

[Means to solve the problem]

The present invention focuses on irradiating a sample with a focused laser beam on a sample placed in an atmosphere containing a compound gas that forms a conductive substance through a dissociation reaction, and performs thermal CVD mainly due to a local temperature increase at this irradiation point. By the action, a conductive substance is locally deposited near the irradiation point, and by scanning the sample relative to the laser beam, the conductive substance is continuously deposited on the sample to form wiring. In a laser CVD apparatus, an XY stage is used as a means for scanning the sample relative to the laser beam, and two of the XY stages
One of the axes is installed inside the chamber used to hold the sample in the compound gas atmosphere, and the other axis is installed outside the chamber so as to move the entire chamber. be.

[Effect]

According to the present invention, one axis of the XY stage is placed in the chamber,
By placing the other axis outside the chamber so that it moves the entire chamber, a long and thin glass window with a length only in the direction of movement of the stage placed outside the chamber can be used, so even if the plate thickness is thin, the pressure difference can be maintained. I can endure it. Therefore, it is possible to handle large samples while keeping the thickness of the glass window relatively thin. Furthermore, with the above configuration, the chamber volume can be made smaller than in the case of an internal chamber type, and the device can also be made smaller.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is an overall configuration diagram showing an embodiment of a laser CVD apparatus according to the present invention. In this example, a visible laser such as an Ar laser or the second harmonic (SH light) of a Q-switched Nd:YAG laser is used as the laser 10, and dungesten carbonyl (W(CO)6) is used as the raw material compound. This shows the case where tungsten wiring is formed on an LSI chip or an LCD substrate by CvD.

The raw material compound W (Co) a is solid at room temperature, and is heated and gasified in a container called a reservoir 11 .

The saturated vapor pressure at this time is approximately 1.2T at 65°C.

It is rr. The gasified −(CO) g is mixed with 12 g of carrier gas (argon was used in this example) to give 1 g.
The compound gas 13 is sent into the chamber 14 at approximately atmospheric pressure. This is because the vapor pressure of gasified W(CO)s is low.

The inside of the chamber 14 is filled with compound gas 13,
The sample 15 is placed in this chamber 14, and the stage 1
6 is heated to about the atmospheric gas temperature by a built-in heater. This is because W(CO)6 does not reaggregate on the surface of the sample 15. In this state, by focusing the laser beam 17 on the surface of the sample 15, a tungsten thin film is deposited near the laser beam irradiation area.

When the focused diameter of the laser beam is about 2 μm, deposition is performed with an average output of about 10 QmW in the case of an Ar laser and about 1 ml in the case of the SH light of a Q-switched Nd:YAG laser.

To form the wiring, the sample 15 may be scanned by the XY stages 18 and 19. In this way, the tungsten deposits are successively connected in the lateral direction, resulting in a tungsten interconnect. XY stage 18 at this time.
The moving speed of 19 is about 0°5 μm/s to 5 μm/s.

FIG. 2 is a perspective view showing the relationship between the XY stage 18, 19 and the chamber 14 according to the present invention. As shown in the figure, an X-axis XY stage 18 is arranged below the chamber 14, while a Y-axis XY stage 19 is arranged inside the chamber 14. Therefore, the X-axis stroke direction (arrow A direction)
Since the entire chamber 14 is moved, the glass window 20 provided on the upper wall of the chamber 14 does not need to cover the entire surface of the sample 15. Note that arrow B indicates the Y-axis stroke direction.

The opening dimensions of the glass window 20 are approximately 20 mm on the short side and approximately the same as the dimension of the sample 15 in the X direction on the long side. In this way, the short side dimension only needs to be about 20 embryos regardless of the sample size, so even in the case of sample 15, which is 450 mm square, the thickness is 3
A glass window 20 of ~4 mm can withstand a pressure difference of 1 atmosphere. In addition, since the chamber 14 only needs to cover the Y-axis, it can be made smaller compared to the case where the entire XY stage is built in. When a 6-inch square sample 15 is the target, the internal space of the chamber 14 is about 101 (mechanism). (excluding the volume occupied by parts).

Further, as shown in FIG. 1, the laser beam 17 is expanded by a beam expander 21 and then passed through an objective lens 22 to
The objective lens 22 has a focal length of 11 m+++ and a working distance of 14.5 m.
I used one from M. Therefore, if the glass window 20 has a thickness of 3 to 4 mm, the vertical stroke of the objective lens 22 can have an allowance of several mI++, resulting in a sufficiently practical system.

The objective lens 22 also serves as an observation lens for the eyepiece 23 or TV left camera 4, so it has a short focus (focal length 1
1■) will be required. In FIG. 1, reference numeral 25 is a monitor, 26 is a heater, 27 is a gicroic mirror, 28 is an exhaust gas treatment section, and 29 is an exhaust gas.

Further, an opening/closing i30 is provided on the left side wall of the chamber 14.

〔Effect of the invention〕

As explained above, according to the laser CVD apparatus according to the present invention, one of the two axes of the XY stage is installed inside the chamber, and the other axis is installed outside the chamber so as to move the entire chamber. By doing so, the thickness of the glass window for introducing the laser beam can be kept relatively thin regardless of the external dimensions of the target sample, which not only makes it possible to design and manufacture optical systems, but also enables XY Compared to the conventional method where the entire stage is built inside the chamber, the internal volume of the chamber itself can be made much smaller, and it has various advantages such as making it possible to apply metal thin film patterning technology using laser CVD to large samples. It has a great effect.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a laser CVD apparatus according to the present invention, FIG. 2 is a perspective view showing the relationship between the chamber and the XY stage of the embodiment shown in FIG. 1, and FIGS.
Figures (A) and (C) are schematic diagrams showing the configuration of conventional examples, respectively, and Figure 4 (B) is an enlarged sectional view of section B in Figure 4 (A). 10... Laser, 14... Chamber, 15... Sample, 17... Laser light, 18.19... xY stage, 20・・・・・・
・Glass window, 21... Beam expander, 22...
・Objective lens. Applicant NEC Corporation Agent Patent Attorney Umeo Yamauchi Figure 2 Figure 4 (C,)

Claims (1)

[Claims] 1. A laser beam is focused and irradiated onto a sample placed in an atmosphere containing a compound gas that forms a conductive substance through a dissociation reaction, and the local temperature mainly at this irradiation point is Heat C due to rise
A conductive substance is locally deposited near the irradiation point by VD action, and by scanning the sample relative to the laser beam, the conductive substance is continuously deposited on the sample to form wiring. In the laser CVD apparatus for forming the sample, an XY stage is used as a means for scanning the sample relative to the laser beam, and one axis of the two axes of the XY stage holds the sample in the compound gas atmosphere. What is claimed is: 1. A laser CVD apparatus, characterized in that the apparatus is installed in a chamber used to move the entire chamber, and another axis is installed outside the chamber so as to move the entire chamber. 2. The laser CVD apparatus according to claim 1, wherein the laser beam is expanded by a beam expander and then focused onto the sample by an objective lens.