JP2901984B2 - Conductive thin film manufacturing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for forming a conductive thin film on an insulating substrate.

[Prior art] Thin film production methods generally include a vapor deposition method, an ion plating method, a sputtering method, and a CVD method, among which relatively easy, high adhesion of the film, and excellent mass productivity. The sputtering method used is often used, and the area has been considerably increased in recent years.

FIG. 4 shows the configuration of a conventional general DC bipolar sputtering apparatus. In the figure, 1 is a substrate such as glass, 2 is a substrate holder for supporting the substrate 1, 3 is a tray for supporting the substrate holder 2 (also referred to as a transport cart in the case of a single-wafer sputtering apparatus), and 4 is a target material. The substrate holder 2 and the tray 3 are usually formed of a conductive material such as stainless steel, and the tray 3 is electrically connected to the apparatus body in some form.

[Problems to be Solved by the Invention] When a conductive thin film is formed on an insulating substrate by the conventional sputtering method, thread-like film peeling may occur on the substrate surface, and this defect increases the film forming area. The higher the rate, the lower the yield of film formation on a large substrate. The cause of this defect is that in the sputtering method, the substrate side is usually set to the ground potential and a negative electric field is applied to the sputter target side to perform discharge. Charges up.

Therefore, for example, when the substrate holder is in conduction with the apparatus main body, the film formation proceeds, and a conductive thin film is formed on the boundary between the substrate and the substrate holder. It flows to the apparatus main body at a stretch through the conduction point between the substrate and the substrate holder. Due to the current generated at this time,
It is considered that film peeling occurs on the substrate surface. Due to this defect, there is a problem that it is difficult to produce a conductive thin film with good yield, especially in a large area.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the prior art and to manufacture a large-area conductive thin film with good yield.

[Means for Solving the Problems] A conductive thin film manufacturing apparatus according to the present invention includes a substrate holder for holding an insulating substrate on which a film is to be formed, a tray for mounting the substrate holder in a film forming apparatus main body, In a DC bipolar sputtering apparatus comprising an insulator for electrically insulating the substrate from the film forming apparatus main body, the substrate holder is mounted on the tray via an insulator, and a lower surface of the substrate holder is provided. A plate member for preventing a target material from flying is provided on the outer edge portion at a distance from the holder.

In one embodiment, the target material fly-preventing plate is formed by projecting a lower edge of the tray.

[Operation] When a conductive film is formed on an insulating substrate, in a DC bipolar sputtering apparatus, the substrate holder is mounted on a tray via an insulating material, and the target material is prevented from flying to the outer edge of the lower surface of the substrate holder. Since the plate material is provided at a distance from the holder, the phenomenon that the charged electrons on the substrate flow out to the apparatus main body at a stretch through the conductive film does not occur, and film peeling does not occur.

Embodiment FIG. 1 shows an example of a sputtering apparatus according to the manufacturing method of the present invention, and shows the same DC bipolar sputtering apparatus as in FIG. A substrate 1 made of glass or the like is held by a holder 2 made of stainless steel or the like. Reference numeral 3 denotes a tray, which is grounded via an apparatus main body (not shown). 4 is a target.

Reference numeral 5 denotes an insulator such as ceramic for insulating the substrate holder 2 and the tray 3 from each other. Although a gap of only 5a is opened between the holder 2 and the tray 3 by the insulator 5, a conductive thin film is formed on a part of the surface of the insulator 5 by the wraparound of the target material. In order to provide insulation, a gap 5b between the insulator 5 and the holder 2 and a length as a barrier from the target material of the insulator 5 by the tray 3
5c is required. These gaps and lengths 5a to 5c correspond to the substrate, target size, cathode anode (C-
A) Depending on the distance between the substrates, the flatness of the substrate holder, the film forming conditions, etc., it is appropriate that the thickness is about 0.3 to 1.5 mm for 5a, about 0.1 to 1.0 mm for 5b, and about 10 to 40 mm for 5c.

As shown in FIG. 1, according to the present invention, since the substrate 1 and the substrate holder 2 are insulated from the apparatus main body, the substrate 1
In addition, the charged electrons do not flow out onto the substrate holder 2, so that it is possible to prevent the thread-like film peeling due to the outflow of the electrons, which is a problem of the prior art, and the yield is greatly improved.

Although not shown in the drawing, it goes without saying that the same effect can be obtained even if an insulator is arranged between the substrate 1 and the substrate holder 2.

In the method of manufacturing a conductive thin film using the apparatus of the present invention, since the film formation is completed while the substrate or the substrate holder remains charged, the substrate or the substrate holder is neutralized by a static elimination blow or the like after film formation in order to prevent dust adhesion or the like. Is preferred.

Specific examples of the present invention are shown below. A glass substrate 50 having a substrate size of 300 × 300 × t1.0 (mm) with the configuration shown in FIG.
A transparent electrode (ITO) 2000 Å was formed on each sheet. The discharge pressure at this time was 3 mTorr, the current was 2 A, the distance between CA was 50 mm, and ceramic was used as the insulator 5 in FIG.
5a = 0.5 mm, 5b = 0.1 mm, and 5c = 30 mm. As a result, the film formation yield was 100%, and no film peeling due to electron outflow was observed. Further, the results of film formation performed while changing the substrate size are shown in graphs in FIG. 2 and FIG.

FIG. 2 shows the result of the defect rate when the substrate size was changed in the configuration of the present invention. For reference, FIG.
The result of the defect rate when forming a film with the configuration shown in the figure is shown.

As shown in FIG. 3, the substrate size is 50 in the conventional manufacturing method.
When it was about 0 cm ² or more, many defects due to the outflow of electrons occurred, and the defect rate sharply increased as the area increased. On the other hand, as shown in FIG. 2, in the manufacturing method of the present invention, the result that the defect rate was 1% or less was obtained even when the substrate size was about 2000 cm ² .

The insulating substrate on which the above-described conductive thin film is formed can be used as an insulating substrate constituting a liquid crystal cell, for example, a ferroelectric liquid crystal cell.

Further, in the present invention, rf (high frequency) sputtering, plasma CVD, or ion plating can be applied in addition to the above-described sputtering.

[Effects of the Invention] As described above, according to the present invention, it is possible to solve the conventional problem of film peeling due to outflow of electrons during formation of a conductive film, and to manufacture a large-area conductive thin film with high yield. become.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a DC bipolar sputtering apparatus according to the present invention, FIG. 2 is a graph showing a defect rate of a thin film manufactured by the apparatus of FIG. 1, and FIG. 3 is a conventional DC bipolar sputtering apparatus. FIG. 4 is a configuration diagram of a conventional direct current bipolar sputtering apparatus. 1: substrate, 2: substrate holder, 3: tray, 4: target, 5:
Insulator.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akio Yoshida 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Shunji 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (56) References JP-A 57-158762 (JP, U) JP-A 63-73356 (JP, U) JP-A 59-112953 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) C23C 14/00-14/58 H01J 37/305 H01J 37/20

Claims (2)

(57) [Claims] A substrate holder for holding an insulating substrate on which a film is to be formed, a tray for mounting the substrate holder in a film forming apparatus main body, and electrically insulating the substrate from the film forming apparatus main body. In a direct current bipolar sputtering apparatus comprising an insulator, the substrate holder is mounted on the tray via an insulator, and a plate for preventing a target material from flying is placed on the outer edge of the lower surface of the substrate holder from the holder. An apparatus for producing a conductive thin film, which is provided at an interval. 2. The conductive thin film manufacturing apparatus according to claim 1, wherein the target material fly-preventing plate is formed by projecting a lower edge of the tray.