JPH09256156A - Film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evade eliminate variations in film thickness depending on the places of a substrate holder by making a constitution in which a object shielding an evaporating material is not present between an evaporating source and a substrate fixed to a substrate holder. SOLUTION: A cage body 22 is nor rotated, and a substrate holder is fixed by substrate holder fixtures 24 and 25. The fixture 24 is mounted to the cage body 22 freely rotatably, and the fixture 25 is mounted to a rotation driving axis 22 by a constitution sliudable in the axial direction. Moreover, the substrate holder has at least two masks for forming electrodes, and the one free from projections on the surface is used at least as one mask. Thus, both of the substrate holder and a vapor deposition jig have a constitution in which they are not made shields above the masks for forming electrodes, therefore, only small shielding by the thickness of the substrate holder (the angle θ2 from A' to B') shall be applied.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a film forming apparatus.

[0002]

2. Description of the Related Art It is old to form a metal thin film on the surface of a substrate and use it as an electrode or a circuit pattern, or to provide a thin film excitation electrode on a piezoelectric substrate and apply alternating current to the electrode to cause resonance to serve as a reference frequency source. Has been done from. In many cases, a thin film excitation electrode is provided on a piezoelectric ceramic or a single crystal having a piezo effect to be used as a vibrator, but for film formation of a metal thin film, a vibrating piece is placed in an appropriate jig in a vacuum chamber, It is performed by methods such as vapor deposition and sputtering. What is used for the substrate and what is used for the film-forming material are merely choices in forming a thin film, and therefore, in the following, as an example,
The description will be made assuming that the electrode formation of the T-cut crystal unit is performed by the vacuum deposition method, but the present invention is not limited to the example.

FIG. 11 shows an AT housed in a cylinder type container.
It is a perspective view of a cut crystal oscillator. The AT-cut crystal resonator is composed of an airtight terminal 4 having two lead terminals 5, a crystal vibrating piece 2 and a metal cover 1, and an electrode 3 is formed on the crystal vibrating piece 2. The AT-cut crystal unit is a step of processing a raw quartz crystal into a desired AT-cut crystal vibrating piece 2, a step of forming an electrode 3 on the crystal vibrating piece 2, a hermetic terminal 4.
The mounting step of fixing the crystal vibrating piece 2 to the lead terminal 5, the adjusting step of adjusting to the desired frequency, and the step of hermetically sealing the crystal vibrating piece 2 with the metal cover 1.

In the step of forming an electrode on the quartz crystal vibrating piece, the main purpose is to form an exciting electrode for taking out an electric signal, but at the same time, it is also an object to roughly adjust the vibration frequency. It is known that when a mass is uniformly applied on the surface of a quartz-crystal vibrating piece, its vibration frequency has a characteristic of decreasing. In the step of forming the electrode, the mass of the electrode film is added to the quartz crystal vibrating piece to reduce its vibration frequency. This decreasing amount is called an electrode drop amount or a plate back amount. The plate back amount varies depending on the area, density, film thickness of the electrode film, the size of the crystal vibrating piece, the frequency, and the like. The material of the electrode film is silver, gold,
Nickel, aluminum, palladium or the like is used, and depending on the application, chrome or titanium may be used as a base and the electrode material may be laminated thereon.

FIG. 1 is a front view showing the inside of a conventional vacuum vapor deposition machine. The vapor deposition chamber 6 has a vapor deposition source 7 for vapor-depositing the electrode 3 on the AT-cut quartz crystal vibrating piece (hereinafter referred to as a work oscillator) 2. The vapor deposition material 8 is appropriately selected from the above-mentioned materials. Above the vapor deposition source 7, a substrate holder 9 in which a large number of work vibrators 2 as works are arranged and housed, and a film thickness monitor 11 for controlling the plate back amount are arranged. The film thickness monitor 11 has a monitor crystal 12 and is connected to an oscillator 13. Monitor crystal 12
The change in the vibration frequency of the
The vapor deposition rate and film thickness are controlled by. Board holder 9
Is fixed to the guide by the vapor deposition jig 10. Although the vapor deposition jig 10 is described in a state of floating in the air, it is installed with a function described later, and is omitted in the drawing. FIG.
[Fig. 3] is a bottom view showing the inside of the vacuum vapor deposition machine. Ten vapor deposition jigs 10 are arranged, and the whole is rotated in the direction of the arrow.

In the process of forming the electrode 3 on the work vibrator 2, the main purpose is to form an excitation electrode for extracting an electric signal, but at the same time, the vibration frequency is roughly adjusted to a constant target value. It is also intended to put in.
Since the variation of the vibration frequency of the work vibrator 2 after the film formation is greatly influenced by the variation of the electrode film thickness, it is necessary to make the electrode film thickness of the work vibrator 2 in the vapor deposition chamber 6 as uniform as possible. When the vapor deposition source 7 is located in the lower center of the vapor deposition chamber 6 as shown in FIG. 1, by disposing the substrate holder 9 on the uniform film thickness surface of the vapor deposition source 7, a film having a relatively good distribution can be formed. However, if there are multiple evaporation sources 7 because they use several kinds of evaporation materials (the evaporation sources cannot be arranged in the center), or if the evaporation sources are linear rather than dots, it is not possible to obtain a uniform film thickness surface. By rotating the jig 10, the film forming conditions of the whole (10 vapor deposition jigs) are made the same.

The substrate holder 9 is also rotated in order to form the same film on both surfaces of the work vibrator 2. By rotating the substrate holder 9 so as to be orthogonal to the line connecting the vapor deposition source 7 and the substrate holder 9, the same film can be formed on both surfaces of the work vibrator 2. FIG. 3 is an example of a substrate holder, and is a front view and a side view. Lower plate 15, mask 16 for electrode formation, 1
8, a substrate guide spacer 17, an upper plate 19, and a fixing screw 20. The vapor deposition involves evacuation and one cycle is long, and it is desirable to store as many work vibrators 2 in the substrate holder 9 as possible. FIG. 4 shows FIG.
3 is a sectional view taken along line AA of FIG.

FIG. 5 is a front view and a side view in which the substrate holder 9 is set on the vapor deposition jig 10. Only the outer shape of the substrate holder 9 is shown by a dotted line. The substrate holder 9 is a vapor deposition jig 10.
It is inserted into the guide part 21 from above in the figure. In this state, the vapor deposition jig 10 rotates as shown by the arrow in the figure. FIG. 6 is a BB sectional view of FIG.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As shown in FIG.
In the substrate holder, the lower plate 15 and the upper plate 19 project vertically like a crosspiece. Further, as shown in FIG. 6, the guide portion of the vapor deposition jig has a structure further protruding. FIG. 7 shows a vapor deposition source 7.
FIG. 3 is a schematic diagram showing a positional relationship when the vapor deposition jig 10 and the substrate holder 9 are rotated. It can be seen that the guide portion 21 shields the evaporated material while it rotates by the angle θ ₁ from A to B, and that the film forming conditions change depending on the position where the work vibrator is arranged in the substrate holder. The thicker the guide portion 21, the greater the influence. It can be said that the thicknesses of the lower plate 15 and the upper plate 19 are the same. If a shield exists between a certain work vibrator 2 and the vapor deposition source 7, the work vibrator without a shield and the vapor deposition conditions change. This is a cause of variations in a crystal unit whose vibration frequency changes depending on the thickness of the deposited film. Also, the efficiency of vapor deposition is poor.

[0010]

A vapor deposition chamber, a vapor deposition source installed in the lower portion of the vapor deposition chamber, a substrate holder arranged above the vapor deposition source for aligning and fixing a substrate on which a film is formed, and the substrate holder With a vapor deposition jig that fixes the guide and revolves the substrate holder above the vapor deposition source, a film thickness monitor that monitors the film thickness formed on the substrate, and a controller that controls the vapor deposition source based on the information from the film thickness monitor. In the film forming apparatus configured, there is no structure that shields the evaporated material between the vapor deposition source and the substrate fixed to the substrate holder.

The substrate holder is composed of at least two electrode forming masks and a substrate guide spacer, and at least one electrode forming mask has no protrusions on the surface.

[0012]

FIG. 8 is a front view and a side view showing an embodiment of a structure in which a vapor deposition jig and a substrate holder do not serve as shields. The housing 22 does not rotate, and the substrate holder 9 is fixed by the substrate holder fixing tools 24 and 25. The substrate holder fixing tool 24 is rotatably attached to the housing 22, and the substrate holder fixing tool 25 is attached to the rotation drive shaft 23 in a structure capable of sliding in the axial direction.

FIG. 9 shows two masks 30 and 31 for forming electrodes.
FIG. 3 is a front view and a side view of a substrate holder including a substrate guide spacer 32. FIG. Electrode forming mask 30
A guide pin 33 is implanted in the substrate and is used for positioning the substrate guide spacer 32 and the electrode forming mask 31. The electrode forming masks 30 and 31 are magnetized so as to be attracted to each other.

FIG. 10 is a schematic diagram showing the positional relationship when the evaporation source and the substrate holder are rotated according to the embodiment of the present invention. Since both the substrate holder and the evaporation jig have a structure that does not become a shield more than the mask for electrode formation, only a portion of the thickness of the substrate holder (angle θ ₂ from A ′ to B ′) is enough for shielding. It is much smaller than the conventional θ ₁ .

[0015]

According to the present invention, since the substrate holder and the vapor deposition jig are structured so as not to be a shield more than the electrode forming mask, the work vibrator (substrate) is located at any position of the substrate holder. However, the same film forming conditions can be used, and vapor deposition can be effectively performed.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic inside of a vacuum vapor deposition machine according to a conventional technique.

FIG. 2 is a bottom view schematically showing the inside of a vacuum vapor deposition machine.

FIG. 3 is a front view and a side view of a conventional substrate holder.

FIG. 4 is a sectional view taken along line AA of FIG.

FIG. 5 is a front view and a side view in which a substrate holder is set on a vapor deposition jig.

6 is a cross-sectional view taken along the line BB of FIG.

FIG. 7 is a schematic diagram showing a positional relationship between a vapor deposition source, a vapor deposition jig, and a substrate holder.

FIG. 8 is a front view and a side view in which a substrate holder is set on a vapor deposition jig according to the present invention.

FIG. 9 is a substrate holder for the present invention.

FIG. 10 is a schematic diagram showing a positional relationship between a vapor deposition source, a vapor deposition jig, and a substrate holder according to the present invention.

FIG. 11 is a perspective view of an AT-cut crystal unit.

[Explanation of symbols]

 1 Metal Cover 2 Crystal Piece 3 Electrode 4 Airtight Terminal 5 Lead Terminal 6 Deposition Chamber 7 Deposition Source 8 Work Vibrator 9 Substrate Holder 10 Deposition Tool 11 Film Thickness Monitor 12 Monitor Crystal 13 Oscillator 14 Controller 15 Lower Plate 16 For Electrode Formation Mask 17 Substrate guide spacer 18 Electrode forming mask 19 Upper plate 20 Fixing screw 21 Guide portion 22 Housing 23 Rotation drive shaft 24 Substrate holder fixing tool 25 Substrate holder fixing tool 30 Electrode forming mask 31 Electrode forming mask 32 Substrate Spacer for guide 33 Guide pin

Claims (2)

[Claims] 1. A vapor deposition chamber, a vapor deposition source installed at a lower portion of the vapor deposition chamber, a substrate holder disposed above the vapor deposition source for aligning and fixing a substrate on which a film is to be formed, and the substrate holder being fixed as a guide. It consists of a vapor deposition jig that revolves the substrate holder above the vapor deposition source, a film thickness monitor that monitors the film thickness formed on the substrate, and a controller that controls the vapor deposition source based on the information from the film thickness monitor. In the membrane device,
A film forming apparatus, characterized in that there is no substance that shields an evaporated substance between the vapor deposition source and the substrate fixed to the substrate holder. 2. The substrate holder comprises at least two electrode forming masks and a substrate guide spacer, and at least one electrode forming mask is a substrate holder having no protrusions on its surface. The film forming apparatus according to claim 1.