JP2910093B2 - Electron beam multi-source evaporator - Google Patents

Description

The present invention relates to a vacuum deposition apparatus, an ion plating apparatus,
The present invention relates to an electron beam multiple evaporation apparatus suitable for application to a film forming apparatus such as an ion mixing apparatus.

"Prior art" As is well known, the above-described film forming apparatus evaporates an evaporating material, which is a raw material of a film, and attaches the evaporating material to a substrate surface. Therefore, an evaporating apparatus for evaporating the evaporating material Is provided. There are various types of such evaporators, and among them, an electron beam evaporator is widely used, in which an evaporation material filled in a crucible is evaporated by irradiating an electron beam with an electron gun. ing.

By the way, in recent years, a plurality of evaporating materials are simultaneously evaporated to form a film by a mixed vapor thereof, and in such a case, a plurality of electron beam evaporating apparatuses as described above are provided. It is provided. FIGS. 5 and 6 show a schematic configuration of an ion plating apparatus including three electron beam evaporators and configured to evaporate three types of evaporation materials at the same time. Reference numeral 1 is a vacuum tank, 2 is a vacuum exhaust port, 3a, 3b, 3c are crucibles, 4a, 4b, 4c are different evaporating materials filled inside the crucibles 3a, 3b, 3c, 5a, 5b, Reference numeral 5c denotes an electron gun provided in each of the crucibles 3a, 3b, 3c, and 6 denotes a substrate as an object to be processed.

As described above, in an ion plating apparatus that forms a film composed of vapors of a plurality of evaporation materials 4a, 4b, and 4c,
In order to form a film of good quality, each evaporating material 4a, 4b, 4c
The mixing ratio of the steam must always be kept constant,
Therefore, the amount of evaporation of each evaporation material 4a, 4b, 4c is detected, and based on the detection result, each electron gun 5
A control device is provided for adjusting the outputs (power) of a, 5b, and 5c to feedback control the amount of evaporation.

As shown in FIG. 5 and FIG. 6, each of these control devices includes an evaporation amount detection sensor 7a, 7b, 7c provided above each of the crucibles 3a, 3b, 3c, and the sensors 7a, 7b, 7c. Evaporation amount calculators 8a, 8b, 8c for calculating the actual evaporation amount of each of the evaporation materials 4a, 4b, 4c based on the detected values, the evaporation amount setting devices 9a, 9b, 9c, which have been set in advance, The calculators 8a, 8b,
The evaporation amount comparators 10a, 10b, 10c comparing the actual evaporation amount calculated by 8c and the set value, respectively, and the comparators 10a, 10c
b, 10c based on the comparison result by electron gun power supply 11a, 11b, 11c
And an electron gun control unit 12a, 12b, 1c that outputs a control signal to the control unit.

"Problems to be solved by the invention" By the way, as described above, a plurality of evaporators are provided,
Moreover, controlling the amount of evaporation of each evaporating material by an independent control device requires a large-scale device and significantly increases equipment costs.

In the above case, the crucibles 3a, 3b, 3c need to secure a predetermined interval between them, so that the crucibles 3a, 3b,
Since the evaporation materials 4a, 4b, 4c filled in 3c cannot be arranged close to each other, the respective crucibles 3a, 3b,
The vapor evaporated from 3c is uniformly mixed only in a narrow range, so that it cannot be applied to a large-sized substrate 6 and most of the evaporation amount is wasted and contributes to film formation. However, there is a disadvantage that only a small part of the evaporation is performed, so that the yield of the evaporation materials 4a, 4b, 4c is not good.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an evaporating apparatus suitable for use when a plurality of types of evaporating materials are simultaneously evaporated.

[Means for Solving the Problems] The electron beam multi-source evaporator of the present invention sequentially irradiates an electron beam to a crucible filled with a plurality of types of evaporation materials and each of the evaporation materials filled in the crucible. An electron gun, and a control device for adjusting the output of the electron gun and the irradiation time of the electron beam to each evaporative material, wherein the control device comprises a plurality of evaporative amounts each of which detects an evaporative amount of each evaporative material. Detecting means, a first comparator for calculating the ratio of the evaporation materials from the amounts of evaporation of the evaporation materials detected by the respective detecting means, and comparing the calculated ratio with a preset evaporation ratio setting value; A second comparator for comparing the evaporation amount of the material with a preset evaporation amount setting value, and adjusting an irradiation time of the electron beam to each evaporation material based on a comparison result of the first comparator; The said A control unit for adjusting an output of the electron gun based on a comparison result of the two comparators.

[Operation] The evaporating apparatus of the present invention detects the evaporation amount of each evaporation material by the evaporation amount detecting means, calculates the ratio thereof by the first comparator, and compares it with a preset evaporation ratio setting value. Accordingly, the irradiation amount of the electron beam to each evaporation material is adjusted so that the ratio of the actual evaporation amount matches the set value of the evaporation ratio. At the same time, by comparing the evaporation amount of at least one of the evaporation materials with the evaporation amount setting value set in advance by the second comparator, the actual evaporation amount of the evaporation material matches the evaporation amount setting value. Adjust the output of the electron gun to do so. This allows
The evaporation amounts of all the evaporation materials are controlled so as to become the evaporation amount set value.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIGS. 1 and 2 are schematic structural views of an ion plating apparatus having an electron beam ternary evaporator according to an embodiment of the present invention. This ion plating device
The three types of evaporating materials 4a, 4b, 4c are simultaneously evaporated by the above-mentioned evaporating device, and the mixed vapor thereof is transferred to the substrate 6 as an object to be processed.
To form a film by vapor deposition on the surface.

The evaporating device is a crucible which is arranged at the center of the bottom in the vacuum chamber 1 and in which the evaporating material is filled.
20, an electron gun 21 provided on the side wall of the vacuum chamber 1, and a control device 22 for the electron gun 21.

The electron gun 21 scans the electron beam with the scanning coil 21a and scans the evaporation material 4a, 4b, 4c in the crucible 20 for several ms.
(Milliseconds) to several hundred ms. Then, the output (power) of the electron gun 21 is controlled by the control device 22, whereby the evaporation materials 4a, 4b,
Not only is the amount of evaporation of 4c controlled, but at the same time
The irradiation time of the electron beam to 4a, 4b, 4c is also controlled by the controller 22, whereby the mixing ratio of the vapor of each of the evaporation materials 4a, 4b, 4c is also controlled.

That is, in general, there is a relationship between the irradiation time of the electron beam and the amount of evaporation of the evaporating material, as shown in FIG. The evaporation amount can be increased or decreased by increasing or decreasing the irradiation time. Therefore, in the case of sequentially irradiating a plurality of evaporating materials with an electron beam, by adjusting the irradiation time to each evaporating material, it is possible to adjust the ratio of the amount of evaporation, that is, the mixing ratio of the vapors. .

In the field of film formation, it is general to express the amount of evaporation of the evaporation material in terms of the film formation rate, that is, the thickness of the film formed in unit time with respect to the unit surface area of the substrate. The unit is often Å / s (angstrom / sec), and the vertical axis in FIG. 3 is also the same.

The configuration of the control device 22 will be described in detail.The control device 22 includes evaporation amount detection sensors 23a, 23b, which are provided above the evaporation materials 4a, 4b, 4c in the crucible 20, respectively.
23c, evaporation amount calculators (evaporation amount detecting means) 24a, 24b, 24c for calculating the evaporation amounts of the evaporation materials 4a, 4b, 4c based on the detection values of the sensors 23a, 23b, 23c, respectively, 4a, 4
A set value (evaporation ratio set value) of a ratio of evaporation amounts of b and 4c (that is, a mixing ratio of steam of each of the evaporation materials 4a, 4b and 4c) is input in advance. 24a, 24b,
Evaporation ratio comparator (first comparator) 26 which receives the calculated value of 24c, calculates their ratio, and compares the calculated value with the set value input to setter 25, three types of evaporation materials 4
Of the values a, 4b, and 4c, the set value (evaporation amount set value) of the evaporation amount of the evaporation material 4a is input in advance to the evaporation amount setter 27, the calculated value from the calculator 24a, and the setter 27. The evaporation amount comparator (second comparator) 28 which compares the set value with the set value, the comparison result of the comparator 26 is input, and the irradiation time of the electron beam to each of the evaporation materials 4a, 4b, 4c is determined based on the input. A control signal is output to the electron gun power supply 29 so as to change the
The control unit 30 outputs a control signal to the electron gun power supply 29 so that the comparison result of the comparator 28 is input and the output of the electron gun 21 is increased or decreased based on the comparison result. As described above, the control device 22 performs feedback control of the output of the electron gun 21 and the irradiation time of the electron beam to each of the evaporation materials 4a, 4b, and 4c.

A specific operation example of the control device 22 will be described with reference to FIG.

The set value of the evaporation amount of each evaporation material 4a, 4b, 4c is shown in FIG.
15a / s, 10% / s, 5% / s
Å / s, so their total value, the total evaporation, is 30Å
/ s, the set value of their mixing ratio is 3: 2: 1, and the output of the electron gun 21 required to obtain such an evaporation amount is 8 kw. The irradiation time of the electron beam to each substance required to obtain such a mixing ratio is 30 ms (millisecond), 20 ms, and 10 ms, respectively, as shown on the left side of FIG.
And In this case, the above-mentioned ratio 3: 2: 1 is input in advance to the evaporation ratio setting device 25, and 15Å / s is input to the evaporation amount setting device 27.
Has been entered.

Now, if for some reason disturbances such that the evaporation amount of the evaporation material 4b drops to 8.5Å / s as shown in the column (b) occur continuously, it is determined by the sensor 23b and the calculator 24b. Is detected, and each evaporating material 4 is
It is detected that the ratio of the evaporation amounts of a, 4b, and 4c changes to 3: 1.7: 1 and differs from the set value. When this is output to the control unit 30, the control unit 30 sends a control signal to the electron gun power supply 29 to extend the irradiation time of the electron beam to the evaporation material 4b in order to increase the amount of evaporation of the evaporation material 4b. Output.

As the irradiation time for the evaporation material 4b is extended,
The irradiation intervals of the electron beams to the evaporation materials 4a and 4c increase, respectively, and as a result, the evaporation amount of the evaporation materials 4a and 4c decreases without changing the irradiation time.

Then, as shown on the right side of FIG.
The irradiation time for 4b was extended to 25ms, and the irradiation interval of the electron beam to the evaporation material 4a was increased accordingly.
When the irradiation interval of the electron beam to the evaporation material 4c changed from 30 ms to 35 ms, and from 50 ms to 55 ms, respectively,
As shown in the column (c), the evaporation amounts of the evaporation materials 4a, 4b, and 4c are 14.4Å / s, 9.6Å / s, and 4.8Å / s, respectively. Therefore, the ratio of the evaporation amounts is the set value. : 2: 1

At this time, although the ratio of the amount of evaporation of each of the evaporation materials 4a, 4b, 4c has recovered to the set value, the amount of evaporation of each of the evaporation materials 4a, 4b, 4c is lower than the set value. The total evaporation amount, which is the total value, is also 28.8Å / s, and the set value is 30Å
It is lower than / s. Therefore, the evaporation amount comparator 28 outputs a control signal to the control unit 30 so as to increase the output of the electron gun 21 to recover the evaporation amount of the evaporation material 4a to the set value.
As a result, the output of the electron gun 21 increases, and
The evaporation amounts of a, 4b, and 4c increase evenly while maintaining the above ratio, and the output of the electron gun 21 becomes 8. as shown in (d).
Assuming that the evaporation amount of the evaporation material 4a has recovered to the set value at the time when the pressure becomes 3 kw, the evaporation amounts of the evaporation material 4b and the evaporation material 4c also automatically recover to the set value, and return to the steady state.

In the above operation example, control of the ratio of the amount of evaporation by adjusting the irradiation time for each evaporation material 4a, 4b, 4c,
Although it has been described that the control of the evaporation amount by adjusting the output of the electron gun 21 is performed individually, actually, the control proceeds simultaneously.

Further, since the output of the electron gun 21 and the ratio of the amount of evaporation of each of the evaporation materials 4a, 4b, and 4c are simultaneously controlled, the output of the electron gun 21 is controlled based on the amount of evaporation of the evaporation material 4a. Instead, the control may be performed based on the amount of evaporation of the evaporation material 4b or 4c, or the output of the electron gun 21 may be controlled based on the total value of all the evaporation amounts. Even so, a similar result is obtained.

For the same reason, it is not necessary to control the irradiation time of the electron beam to all the evaporation materials 4a, 4b, 4c, and the irradiation time to any one of the evaporation materials may be fixed. In this case, it is preferable to fix the irradiation time for the evaporation material having the largest evaporation amount as in the above embodiment.

In the evaporator described above, one crucible 20
Is filled with a plurality of evaporating materials 4a, 4b, 4c, and each of the evaporating materials 4a, 4b, 4c is sequentially irradiated with an electron beam to evaporate. The entire apparatus can be simplified as compared with the case, and the equipment cost can be greatly reduced. The control device 22 in this evaporator includes sensors 23a, 23b, 23c, and a calculator 2
Although only a plurality of 4a, 24b and 24c are required, the other evaporation ratio setting unit 25, evaporation ratio comparator 26, evaporation amount setting unit 27, evaporation amount comparator 28, control unit 30, and electron gun power supply 29 are all A single unit is sufficient, and the control unit in the conventional evaporator which requires a plurality of all units is greatly simplified. In this respect, the equipment cost can be reduced.

Also, in this evaporator, since a single crucible 20 is filled with a plurality of evaporation materials 4a, 4b, 4c, a plurality of crucibles 3a, 3c
It is possible to arrange the evaporation materials 4a, 4b, 4c closer to each other than in the conventional case requiring b, 3c, so that the vapors of the evaporation materials 4a, 4b, 4c are uniformly mixed over a wide range. As a result, the present invention can be applied to a large substrate 6 and can also improve the yield of each of the evaporation materials 4a, 4b, 4c.

The controller 22 controls the output of the electron gun 21 to control not only the amount of evaporation of each of the evaporation materials 4a, 4b, and 4c, but also the control of the electron beam to each of the evaporation materials 4a, 4b, and 4c. By controlling the ratio of the amount of evaporation by adjusting the irradiation time, the mixing ratio of the vapor of each evaporation material 4a, 4b, 4c can always be optimally controlled, and as a result, a high quality and uniform film can be obtained. It can be formed and can operate stably.

The above embodiment is an example in which the present invention is applied to an ion plating apparatus that forms a film using a mixed vapor of three types of evaporation materials. However, the same applies to the case where two or more types of evaporation materials are used. The present invention can be applied to not only an ion plating apparatus but also other film forming apparatuses such as a vacuum evaporation apparatus and an ion mixing apparatus.

[Effects of the Invention] As described above in detail, the multi-element electron beam evaporator of the present invention fills a crucible with a plurality of evaporation materials and sequentially irradiates each of the evaporation materials with an electron beam. Since the apparatus is configured to evaporate, the entire apparatus can be simplified as compared with a case where a plurality of conventional evaporating apparatuses are used, and equipment costs can be significantly reduced. Since it is possible, the vapor of each evaporation material is uniformly mixed over a wide range, and as a result, it is applicable to a large substrate, and the yield of each evaporation material can be improved.

In addition, the control device in the evaporating device includes a detecting unit that detects the amount of evaporation of each evaporating material, and calculates the ratio of the amount of evaporation of each evaporating material, and compares the ratio with the set value of the evaporating material. A first comparator for adjusting the irradiation time of the electron beam, and a second comparator for adjusting the output of the electron gun by comparing the evaporation amount of at least one of the evaporation materials with the evaporation amount setting value. Since the configuration is provided with the comparator, the mixing ratio of the vapor of each evaporation material can always be optimally controlled.

[Brief description of the drawings]

1 to 4 are views for explaining an embodiment of the present invention, and FIG. 1 is a side sectional view showing an overall schematic configuration of an ion plating apparatus including an evaporator of the present embodiment;
FIG. 2 is a partial plan view, FIG. 3 is a diagram showing the relationship between the irradiation time of the electron beam and the amount of evaporation, and FIGS. 4 (a) and 4 (b) are diagrams showing an operation example of the control device. is there. FIG. 5 is a side sectional view showing the overall schematic configuration of an ion plating apparatus provided with a conventional evaporator, and FIG. 6 is a partial plan view thereof. 1. Vacuum chamber, 4a, 4b, 4c ... Evaporation material, 6 ... Substrate, 20
…… Crucible, 21 …… Electron gun, 21a …… Scanning coil, 22…
… Control device, 23a, 23b, 23c …… Sensor, 24a, 24b, 24c ……
Evaporation amount calculator (evaporation amount detection means), 25 evaporation ratio setting device, 26 evaporation ratio comparator (first comparator), 27 evaporation amount setting device, 28 evaporation amount comparator ( Second comparator), 29
... Electron gun power supply, 30 ... Electron gun control unit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C23C 14/00-14/58

Claims (1)

(57) [Claims] 1. A crucible filled with a plurality of types of evaporating materials, an electron gun for sequentially irradiating each of the evaporating materials filled in the crucible with an electron beam, an output of the electron gun and each evaporating material. A control device for adjusting the irradiation time of the electron beam, the control device includes a plurality of evaporation amount detection means for respectively detecting the evaporation amount of each evaporation material, and each evaporation amount detected by each of the detection means. A first comparator for calculating the ratio between the evaporation amounts of the materials and comparing the calculated ratio with a predetermined evaporation ratio set value; and a predetermined evaporation amount set value for at least one of the evaporation amounts of the evaporation material. A second comparator to be compared and an irradiation time of an electron beam to each evaporation material are adjusted based on a comparison result of the first comparator, and the electron beam is adjusted based on a comparison result of the second comparator. Adjust the power of the gun Electron beam multi-evaporator, characterized by comprising a control unit for.