JPH0649641A - Vacuum deposition device - Google Patents

Abstract

PURPOSE:To provide a vacuum deposition device capable of accurately controlling the optical film thickness of plural vapor-deposition samples at the same time. CONSTITUTION:Each of the plural sample holders 3 in the chamber 1 is provided with a part 6 for mounting a monitor substrate M, a laser beam source for irradiating the substrate M with a laser beam set in a vacuum chamber, an optical system for conducting a reflected light from the substrate obtained by the irradiation with the laser beam source to a light receiving sensor 13 outside the chamber through a window 1a of the vacuum chamber 1 and a shutter 4 to stop the vapor deposition on a vapor-deposition sample on a sample holder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum evaporation apparatus such as a resistance heating apparatus and an electron beam evaporation apparatus, and more particularly to a vacuum evaporation apparatus having a plurality of sample holders in a vacuum chamber.

[0002]

2. Description of the Related Art Conventionally, a crystal oscillator sensor has been widely used as a method for monitoring a vapor deposition film thickness in vacuum vapor deposition such as electron beam vapor deposition. With this method,
Since the geometrical thickness of the thin film is measured by a mechanical method, inaccuracies are involved when forming an optical thin film such as a multi-layered film mirror or AR coat, and the size of the sensor itself and the cooling water It was difficult to install the sensor in the immediate vicinity of the vapor deposition sample due to the problem of piping or wiring of the electric system.

There is an optical monitor system as a system for solving such a problem. This method utilizes the fact that the reflectance or transmittance of a single wavelength light by an optical thin film takes an extreme value when the optical thickness of the film becomes ¼ of that wavelength. FIG. 4 shows an example of the configuration of a conventional vacuum vapor deposition apparatus that employs an optical monitor system.

In this example, a plurality of sample holders 43 are provided in a rotary dome 42 inside a vacuum chamber 41 accommodating vapor deposition sources 40a and 40b which selectively generate a molecular beam via a shutter 400, and a plurality of sample holders 43 are provided. A monitor substrate 44 is disposed in the central portion of 42. The monitor substrate 44 is adapted to be irradiated with the single wavelength light from the probe light generator 47 through the window 45 formed in the vacuum chamber 41 and the reflection mirror 46, and the reflected light is also emitted from the window. The reflected light intensity is introduced into the photodetection circuit 48 through the reflection mirror 45 and the reflection mirror 46, and the reflected light intensity is recorded in the recorder 49. Then, the light intensity by the recorder 49 is monitored, and when the value reaches the extreme value, the vapor deposition of the next film is started. According to this method, there is an advantage that the optical film thickness can be controlled.

In the figure, S is a vapor deposition sample and 5
Reference numerals 0 and 51 are crystal oscillators for the above-described crystal oscillator sensor system and film thickness monitor devices using the starting frequency thereof.

[0006]

By the way, in the above-mentioned conventional optical monitor system, since the probe light generator 47 is located outside the vacuum chamber 41, the vacuum chamber 4 is not provided.
The number of monitor substrates that can be arranged in one is limited, and when a large number of vapor deposition samples S are set, the reflected light or transmitted light by one or several monitor substrates 44 placed at an appropriate place. The film thickness of all vapor deposition samples S will be estimated from the intensity. In such a method, when there is spatial unevenness in the molecular beam intensity from the vapor deposition source 40, it becomes difficult to control the film thickness of each vapor deposition sample S, which is essential.
Even if a plurality of monitor substrates 44 are provided and the spatial unevenness of the molecular beam intensity is calibrated from their reflected or transmitted light intensities, for example, the spatial distribution of the molecular beam may change as the vapor deposition material decreases. Therefore, there is a drawback that the reproducibility is poor.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a vacuum vapor deposition apparatus capable of accurately controlling the optical film thickness of a plurality of vapor deposition samples at the same time.

[0008]

In order to achieve the above object, the vacuum evaporation apparatus of the present invention has a monitor substrate in a vacuum chamber near each holder for each of a plurality of sample holders provided in the vacuum chamber. A monitor substrate mounting portion for mounting on a monitor substrate, a laser light source disposed in a vacuum chamber for irradiating the monitor substrate with a laser beam, and a reflected light from the monitor substrate obtained by the laser beam irradiation. It is characterized in that an optical system for guiding a light receiving sensor provided outside the chamber through a window formed in the vacuum chamber and a shutter for stopping deposition on the deposition sample on the sample holder are provided.

[0009]

The light from the individual laser light source provided in the vacuum chamber is irradiated to each monitor substrate arranged in the vicinity of each vapor deposition sample, and the reflected light is guided to the light receiving sensor outside the vacuum chamber. . Since each monitor substrate is placed in the vicinity corresponding to each vapor deposition sample, even if the molecular beam has a spatial distribution, each monitor substrate has a film formation rate equivalent to that of the vapor deposition sample corresponding to each monitor substrate. It is deposited at a speed. Therefore, the intended purpose can be achieved by closing the shutter provided for each sample holder when the intensity of the reflected light from each monitor substrate by the light receiving sensor reaches the extreme value.

[0010]

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention.
FIG. 2 is an enlarged view showing a detailed configuration in the vicinity of each sample holder 3.

In the vacuum chamber 1 communicating with the vacuum pump, for example, two vapor deposition sources 2a and 2b are arranged, and a shutter for opening one of these vapor deposition sources 2a and 2b. 20 are provided. Each of the vapor deposition sources 2a and 2b evaporates when the temperature is raised by electron beam irradiation or resistance heating.
Only the molecular beam on the side selected by is generated in the vacuum chamber 1.

In the vacuum chamber 1, a plurality of sample holders 3, ...
Are arranged opposite to the vapor deposition sources 2a and 2b, and the molecular beam is 1
In the vacuum chamber 1 kept at 0 ^-7 Torr, the vapor deposition samples S ... S are linearly incident and deposited.

Each sample holder 3, ... Is provided with a shutter 4, .4 for blocking the molecular beam, and these can be individually opened and closed by an operation from the outside.

Each sample holder 3 ...
On each of the bases 5, a monitor substrate holder 6 for mounting the monitor substrate M in proximity to the vapor deposition sample S, a semiconductor laser 7 and its power supply circuit 8, and a semiconductor laser. Collimator unit 9 for converting the laser light from 7 into parallel light having a predetermined cross section, and the beam splitter 1 for passing the laser light passing through the collimator unit 9 to guide it to the monitor substrate M and reflecting the reflected light.
An optical fiber coupling portion 12 that guides the reflected light from the substrate M for monitoring reflected by the beam splitter 10 into the optical fiber 11 is provided.

The tips of the optical fibers 11, ..., 11 mounted on the respective optical fiber coupling portions 12 are guided to the windows 1a formed in the vacuum chamber 1, respectively. Window 1a
A light-receiving sensor 13 is disposed outside of the light-receiving sensor 13, and the reflected light from the respective monitor substrates M, ... M guided by the respective optical fibers 11 ,. ing.

The output of the light receiving sensor 13 is the light detecting circuit 14
After being converted and amplified by, it is introduced into the recorder 15. The semiconductor lasers 7 provided corresponding to the respective sample holders 3 ... 3 are sequentially driven at a predetermined timing, and the recorder substrates 15 mounted on the sample holders 3 ... The reflected light intensity of is recorded sequentially.

In the above structure, the molecular beam is incident on and deposited on each monitor substrate M ... M together with each vapor deposition sample S ... S, but each monitor substrate M. Since they are arranged close to the samples S..S, even if there is some spatial distribution in the molecular beam, the difference in film forming rate between the vapor deposition sample S and the monitor substrate M corresponding to each other is negligible.

As shown in FIG. 3, the relationship between the reflectance and the film thickness when the film being formed by vapor deposition is irradiated with light having a predetermined wavelength, the film thickness is 1/4 wavelength. The maximum and the minimum occur each time. Each monitor board M ...
Also for the recorder 15 that sequentially records the reflected light intensity for each M,
A curve that changes with time according to the film thickness deposited on each of the monitor substrates M ... M is drawn. Therefore, this recorder 1
While monitoring the curve for each monitor substrate M ... M on 5 and closing the corresponding shutters 4 ... 4 at the time when the maximum or the minimum is reached, 1 for each vapor deposition sample S.
A thin film having a thickness of / 4 wavelength is formed. After such a film is formed on all the vapor deposition samples S.
By driving the shutters 20 mounted on a and 2b and shifting to the next vapor deposition operation repeatedly, a highly accurate multilayer film is formed on all the vapor deposition samples S.

A point to be noted in the above-mentioned embodiments is that the semiconductor laser 7 is used as a light source for the probe, whereby the probe light generating portion can be made very compact and the vacuum chamber 1 can be provided. Since the built-in method can be adopted, and the semiconductor laser can be driven by a battery, there is an advantage that the power supply circuit 8 is built in the vacuum chamber 1 and there is no trouble such as introducing an electric current from the outside. .

According to the present invention, in addition to the fixed bases 4 and 4 including the respective sample holders 3, the dome which supports these is rotated, and the system which rotates in addition to this revolution. Can also be applied to. Also,
In the above embodiments, it is needless to say that a crystal oscillator sensor type film thickness monitor can be used together.

[0021]

As described above, according to the present invention,
For each of a plurality of sample holders arranged in the vacuum chamber, a monitor substrate is mounted, a laser light source for irradiating the monitor substrate with laser light, and a monitor substrate obtained by irradiating the laser light Since an optical system for guiding the reflected light of the above through a window formed in the vacuum chamber to a light receiving sensor provided outside the chamber is provided, and a shutter for stopping deposition on the sample on the sample holder is provided. Even when multiple evaporation samples are set in the vacuum chamber for evaporation, the film thickness of each evaporation sample can be individually monitored, and accurate optical film thickness control for many samples is possible. Is possible. Further, since many samples can be processed at the same time, the cost of film formation can be reduced.

Further, when the wavelength of the irradiation light is changed by sweeping the wavelength of the laser light source or selecting each laser light source, vapor deposition of various film thicknesses can be simultaneously advanced for each sample.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of an embodiment of the present invention

FIG. 2 is an enlarged view showing a detailed configuration in the vicinity of each sample holder 3.

FIG. 3 is a graph showing a relationship between reflectance and film thickness when a film being formed by vapor deposition is irradiated with light having a predetermined wavelength.

FIG. 4 is a cross-sectional view showing a configuration example of a conventional vacuum vapor deposition apparatus adopting an optical monitor system.

[Explanation of symbols]

 1 vacuum chamber 1a windows 2a, 2b vapor deposition source 20 shutter 3 sample holder 4 shutter 5 base 6 monitor substrate holder 7 laser light source 8 power supply circuit 9 collimator section 10 beam splitter 11 optical fiber 12 optical fiber coupling section 13 light receiving sensor 14 light Detection circuit 15 Recorder S Deposition sample M Monitor substrate

Claims (1)

[Claims] 1. A vacuum vapor deposition apparatus having a plurality of sample holders in a vacuum chamber, wherein a monitor substrate mounting portion for mounting a monitor substrate in the vacuum chamber near each holder for each sample holder. And a laser light source disposed in the vacuum chamber for irradiating the monitor substrate with a laser beam, and reflected light from the monitor substrate obtained by the laser beam irradiation through a window formed in the vacuum chamber. An optical system that guides a light receiving sensor provided outside the chamber,
A vacuum vapor deposition apparatus comprising: a shutter for stopping vapor deposition on a sample on a sample holder;