JPH04160150A - Method and device for controlling heating by electron beam - Google Patents

Abstract

PURPOSE:To accurately inject an electron beam on the specified position of a vapor-deposition material by adding a functional correction consisting of the information on the horizontal deflection angle to the vertical deflection angle of an electron beam, based on the incident position of the electron beam. CONSTITUTION:The vertical and horizontal deflection angles of an electron beam from the injection port 11 of an electron beam gun are controlled by a deflection coil 12 so that the beam describes a path 13. The beam is injected into the vapor-deposition material 15 in a water-cooled copper crucible 14 based on the preset incident pattern to scan the material, along the line of magnetic force of an electromagnet 16. In this method for controlling heating by the electron beam, the incident position of the beam in the preset vertical deflection angle and bisymmetrically oscillated horizontal deflection angle is previously obtained. A functional correction consisting of the information on the horizontal deflection angle is added to the vertical deflection angle based on the incident position, and correction is performed. The control is conducted based on the corrected deflection angle, and the desired incident pattern of the beam is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to controlling the electron beam so that it irradiates a set position when using an electron beam melting device, an electron beam evaporation device, etc. The present invention relates to an electron beam heating control method and an apparatus therefor, in which the electron beam does not deviate from a set position.

[Prior art] Conventionally, heating methods for vacuum evaporation equipment include electron beam heating, high-frequency induction heating, and direct energization. However, electron beam heating has excellent heating controllability and is highly effective for high-temperature heating using water-cooled crucibles. It is suitable for melting melting point metals and is widely used.

FIG. 1 shows a typical configuration of an electron beam heating type vapor deposition apparatus. The electron beam from the exit port 11 of the electron beam gun is deflected by a deflection coil 12 in the y and two directions of the electron beam.
The electron beam is deflected by the electron beam and enters the vapor deposition material 15 in the water-cooled copper crucible 14 with a locus of the electron beam as shown by reference numeral 13.

Electromagnets 16 are arranged on both sides of the crucible 14 to generate a magnetic field that deflects the electron beam toward the crucible surface.

In order to heat the deposited material with this electron beam, it is necessary to correctly control the electron beam to realize a predetermined heating pattern. Conventional small laboratory-scale evaporation equipment has a small heating range and has not caused control problems, but as evaporation equipment becomes larger and wider, the thickness of the deposited metal film increases due to insufficient control of the electron beam. Problems such as unevenness have arisen.

In order to solve these problems, there are methods such as placing helical magnets on both sides of the crucible and scanning the electron beam as in JP-A-1-129963, and methods around the crucible as in JP-A-1-272762. A method of arranging a coil that generates a strong magnetic field to facilitate electron beam scanning has been disclosed. However, it is essentially insufficient to reliably control the electron beam using only these means.

In other words, the electron beam is
It is controlled by a two-axis deflection coil 12 installed at.

When a certain heating pattern is assumed, it is required to set an appropriate current value for this biaxial deflection coil and accurately control the electron beam.

[Technical problem to be solved by the invention] The present invention has been made in view of the above circumstances, and its purpose is to:
The present invention provides a control method that allows an electron beam to correctly enter a predetermined position, and a control device that can switch to flow different electron beam control currents during vapor deposition and ionization.

[Means and effects for solving the problem] That is, the heating control method of the present invention is to control the vertical deflection angle and the horizontal deflection angle of the electron beam from the electron beam gun for heating the evaporation material. A heating control method for an electron beam in which the electron beam is incident on a vapor deposition material based on an incident pattern, and the incident position of the electron beam is obtained in advance at a fixed vertical deflection angle and a horizontal deflection angle that is symmetrically swung. Then, based on this incident position, a correction is performed by adding a function system consisting of information on the horizontal deflection angle to the vertical deflection angle, and the electron beam is This is a method of controlling heating of an electron beam so that it has a desired incident pattern.

Further, the first heating control device of the present invention controls the vertical deflection angle and horizontal deflection angle of the electron beam from the electron beam gun for heating the evaporation material, and controls the electron beam based on the preset incident pattern of the electron beam. This is an electron beam heating control device that injects the beam into the evaporation material, and includes a detector that detects heating stages by the electron beam, and a pattern of vertical deflection angle and horizontal deflection angle corrected corresponding to each heating stage is input. Select a voltage generator with a corresponding pattern from among multiple voltage generators based on the creation of the above pattern, human input to the voltage generator, and signal from the detector, and generate voltage. This is an electron beam heating control device comprising a computer that starts and stops the device, and a control means that controls the vertical deflection angle and horizontal deflection angle of the electron beam based on the output voltage from the voltage generator. .

Further, the second heating control device of the present invention does not control the vertical deflection angle and the horizontal deflection angle of the electron beam from the electron beam gun for heating the evaporation material, but also controls the vertical deflection angle and the horizontal deflection angle based on the preset incident pattern of the electron beam. An electron beam heating control device for injecting an electron beam into a vapor deposition material, the device comprising: a detector for detecting a heating step by the electron beam; and a pattern of deflection current of the electron beam based on an output signal from the detector;
a computer that corrects the vertical deflection angle based on the detected pattern and outputs voltages related to the vertical deflection angle and horizontal deflection angle; an amplifier that amplifies the output voltage signal from the computer; This is an electron beam heating control device comprising a control means for controlling a vertical deflection angle and a horizontal deflection angle of an electron beam based on the above.

The trajectory of the electron beam from the electron beam gun is determined by the electromagnet 16.
It fluctuates greatly depending on the magnetic field generated by the magnetic field.

In order to accurately understand these magnetic field distributions, the present inventor conducted magnetic field analysis and measurement of magnetic field distributions.

Figure 2 shows the magnetic flux line distribution determined by analysis.

In the figure, 21 is an electron beam exit port, 22 is an electromagnet yoke, and 2
3 is an electromagnetic coil, 24 is a deposition surface, 25 is a magnetic flux line, 26
is the magnetic flux density vector. These analysis results agreed well with the measured values. The velocity component of the electron beam in a direction perpendicular to the magnetic flux density vector 26 is deflected. That is, the trajectory of an electron beam in a magnetic field is expressed by the equation (1).

m-dV/d t-eVXB Equation (1) where m is the mass of the electron, t is time, ■ is the velocity vector, e is the charge of the electron, B is the magnetic flux density vector, and X is the outer product. Figure 3 shows the landing point of the electron beam on the crucible surface when the vertical angle θy of the beam is constant and the horizontal angle θ2 is changed by the formula (
The results calculated according to 1) and the experimental results are shown below. Here, 31 is θy--12,5°, -15,0°, -17,
5°.

-20°≦θ2≦20′″ shows the landing line of the beam on the crucible according to the analysis, and the area 32 surrounded by diagonal lines is θy
The experimental results are shown for the landing point with 02 = -12.5°, and the two agree well.

Note that 33 is the glue inside the crucible. From this figure, it can be seen that even if the vertical angle is constant, the landing point of the beam is curved. These curvatures become a problem when heating a rectangular crucible surface. In order to solve this problem, it is necessary to provide current vertical angle information to the horizontal scan and add correction. That is, θy−a+f (t)+I (θ2) Formula (2
) θz−b+g (t) Equation (3) where θy is the vertical angle of the electron beam, θ2 is the horizontal angle of the electron beam, a, b are offsets, f (t), g (t) are functions of time, 1 (θ2) is a correction function of θy. I (
The functional form of θ2) is, for example, C(θ2)'', and the third
It is determined from the trajectory of the electron beam on the crucible shown in the figure. Here, C is a constant value. The relationship between θy, 02, and the deflection current of the electron beam is proportional, and the relational expressions (2) and (3) can be directly converted into a deflection current value.

By controlling the vertical deflection angle and the horizontal deflection angle based on equations (2) and (3), it is possible to control the input position of the electron beam with a desired entrance pattern.

However, during vacuum evaporation, when the evaporation shifts to ion blating, the trajectory of the electron beam changes due to the generation of a magnetic field accompanying the ionization current.

Therefore, it is necessary to change the current pattern flowing through the deflection coil 12. In this case as well, the vertical deflection angle and horizontal deflection angle during ion blating are measured in advance, and the equation (2,) during ion blating is
If (3) is determined in advance, it will be possible to respond appropriately.

[Example] As described above, the method of the present invention was carried out by correcting the vertical angular deflection of the electron beam by adding a functional form consisting of horizontal angular information. The results are shown in FIG. On the other hand,
Figure 5 shows 1 (θZ)-0 in equation (2), θy, θ2
We show how to control independent comparison. As in the present invention, by adding the additional control term (2) to θy in equation (2), it has become possible to linearly control the electron beam. By controlling using these relational expressions, it becomes possible to control an arbitrary electron beam.

An example of a device that can appropriately carry out this control method is the device shown in FIG. This device is equipped with a detector 41 that detects the ionization current to detect the heating stage of vapor deposition or ion blating, and is also provided with a disk 42 containing various current patterns in advance. and detector 41
The heating stage detection signal of the rice bran is inputted to the computer 43. A voltage pattern corresponding to the current pattern of the heating stage is set in advance in each voltage generator 44 by the computer 43, and the computer 43 selects the voltage generator 44 corresponding to the detected heating pattern. The voltage generator 44 generates a set voltage pattern (
θy, θ2) is transmitted at a predetermined frequency. Based on this signal, the control means 45 controls the trajectory of the electron beam from the electron beam gun. The control computer 43 has functions such as creating, changing, and managing voltage patterns, and switching and controlling voltage generators. Reference numeral 46 denotes an oscilloscope for visually observing the signal from the computer 43.

According to this device, since a plurality of voltage generators 44 are provided that set voltage values according to ionization current values, by detecting a current pattern and switching the voltage generators 44 according to the detected value, It is possible to control the desired heating pattern during vapor deposition and ion blating.

FIG. 7 shows another control device. This device is equipped with a detector 51 that detects ionization current to detect the heating stage of vapor deposition or ion blating, and is also provided with a disk 53 containing various current patterns in advance. Then, the heating stage detection signal from the detector 51 is input to the computer 52. The computer 52 searches for a deflection current pattern of a predetermined electron beam within the disk 53 based on the heating stage detection signal I, and corrects the vertical deflection angle based on the searched current pattern. Furthermore, the voltage pattern (θy) corresponding to the detected heating stage.

θZ). The output voltage from the control computer 52 is input to the amplifier 54, where the output voltage is amplified,
Vertical angle signal (θy) and horizontal angle signal (θ2
). Based on this signal, the control means 55 controls the trajectory of the electron beam from the electron beam gun. In addition, 1
The IlIIl computer 52 creates voltage patterns,
It has functions such as changing, managing, switching and controlling voltage amplifiers. 56 is an oscilloscope.

[Effects of the Invention] As explained above, according to the present invention, accurate control of the electron beam has become possible by adding a functional form consisting of horizontal angle information to the vertical angle deflection of the electron beam.

Further, it is possible to switch to flow different electron beam control currents during vapor deposition and during ionization.

[Brief explanation of the drawing]

Figure 1 shows a typical electron beam evaporation device, Figure 2 shows the magnetic field distribution around the crucible determined by analysis, and Figure 3 shows the trajectory of the electron beam on the crucible determined by analysis and experiment. FIG. 4 is a diagram showing an example of the trajectory of an electron beam accurately controlled in a straight line according to the present invention, FIG. 5 is a diagram showing the trajectory of an electron beam according to the conventional method, and FIGS. FIG. 6 is a block diagram showing different examples of the device of the present invention. DESCRIPTION OF SYMBOLS 11... Emission port of electron beam gun, 12... Deflection coil of electron beam in y and two directions, 13... Trajectory of electron beam, 14... Water-cooled copper crucible, 15... Vapor deposition material, 16... Electromagnet, 21... Electron beam exit port, 22... Electromagnetic yoke, 23... Electromagnetic coil, 2
4... Deposit surface, 25... Magnetic flux line, 26... Magnetic flux density vector, 31... Beam landing line on crucible (analytical value), 32... 02 as θy −-12,5° Landing point where the was swung (experimental value), 33...Glue in the crucible, 41.
...Detector, 42...Disk, 43...Computer, 44...Voltage generator, 45...Control means, 4
6... Oscilloscope, 51... Detector, 52...
Computer, 53...disk, 54...amplifier,
55... Control means, 56... Onroscope applicant's agent Patent attorney Takehiko Suzue b lFll 2nd Ward

Claims (3)

[Claims] (1) While controlling the vertical deflection angle and horizontal deflection angle of the electron beam from the electron beam gun for heating the evaporation material,
An electron beam heating control method in which an electron beam is incident on a vapor deposition material based on a preset electron beam incident pattern, the electron beam being heated at a predetermined vertical deflection angle and a symmetrical horizontal deflection angle. The incident position of the beam is obtained, and based on this incident position, a correction is performed by adding a function system consisting of information on the horizontal deflection angle to the vertical deflection angle, and the corrected vertical deflection angle and horizontal deflection angle are An electron beam heating control method for controlling the electron beam to have a desired incident pattern. (2) While controlling the vertical deflection angle and horizontal deflection angle of the electron beam from the electron beam gun for heating the evaporation material,
An electron beam heating control device that injects an electron beam into a deposition material based on a preset electron beam incident pattern, and includes a detector that detects the heating stage by the electron beam, and a vertical direction corrected corresponding to each heating stage. A plurality of voltage generators into which patterns of deflection angles and horizontal deflection angles are input, and a response is selected from among the plurality of voltage generators based on the creation of the above patterns, input to the voltage generators, and signals from the detector. A computer that selects a voltage generator with a pattern and starts and stops the voltage generator, and a control means that controls the vertical deflection angle and horizontal deflection angle of the electron beam based on the output voltage from the voltage generator. An electron beam heating control device comprising: (3) While controlling the vertical deflection angle and horizontal deflection angle of the electron beam from the electron beam gun for heating the evaporation material,
An electron beam heating control device that injects an electron beam into a deposition material based on a preset electron beam incident pattern, and includes a detector that detects the heating stage by the electron beam, and an electron beam heating control device that A computer that detects the beam deflection current pattern, corrects the vertical deflection angle based on the detected pattern, and outputs voltages related to the vertical deflection angle and horizontal deflection angle, and amplifies the output voltage signal from the computer. 1. An electron beam heating control device comprising: an amplifier; and a control means for controlling a vertical deflection angle and a horizontal deflection angle of an electron beam based on an output voltage from the amplifier.