JPS5941473A - Electron impact heating evaporation source - Google Patents

Abstract

PURPOSE:To provide the titled evaporation source for attaining to uniformize the melting mode of an evaporation material and evaporation distribution, constituted so as to be capable of appropriately varying the step time and/or the step position of electron beam subjecting the evaporation material to step scanning. CONSTITUTION:In an electron impact heating evaporation source wherein electron beam emitted from an electron gun 1 is deflected about 180 deg. by a permanent magnet 2 to be guided onto the evaporation material 4 in a crucible 3 and said evaporation material 4 is evaporated by scanning and heating to form films on substrate 5a-5c by vapor deposition, signals are outputted from digital scanning signal generators 7X, 7Y in directions X, Y on the basis of a step position setting device 10 appropriately made variable by a digital controller 12 and a stop time setting device 11 to control deflecting coils 6X, 6Y in directions X, Y through DA converters 8S, 8Y and amplifiers 9X, 9Y and the evaporation material 4 is scanned. In addition, a step time and/or a step position is appropriately altered by a beam scanning locus.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron impact heating evaporation source in which an electron beam is guided to an evaporation material by deflecting it at an appropriate angle, and the beam is scanned over the evaporation material.

In vacuum evaporation equipment, high frequency ion plating, etc., for example, the evaporation material is placed in a crucible once a month, and the crucible is used as an anode.
Electrons from the cathode filaments 1 are directed onto the evaporation material to bombard the material with the beam and evaporate it. At this time, the vapor hits the cathode filament, causing the filament 1 to break IV! To avoid contamination, the cathode filament is placed in a location where it is not directly exposed to steam, and the electrons from the filament are bent by a magnetic or electric field and guided to the evaporation material. At the same time, the entire surface of the evaporated material is scanned in a rask shape with an electron beam so as to uniformly impact the entire surface of the evaporated material.

However, the electrons from the filament can be moved at a large angle (e.g. 90
'~360') Due to the magnetic pole structure designed for deflection, the shape of the beam is distorted on the evaporation material, and the scanning direction of the beam is distorted, resulting in the impact of the electron beam at certain locations on the evaporation material. There will be differences in the amount of water, and there will be differences in the rate of melting at each location. For this reason, the evaporation distribution of the evaporation material changes over time, and the state of the film formed on the substrate changes. In addition, if the evaporation distribution changes, the whole crucible is replaced with a new one, so some parts that are not dissolved at all or only a small amount remain in the evaporation material of the original crucible, making it difficult to use the evaporation material effectively. On the contrary, it was uneconomical.

The present invention has been made in view of these points, and includes an evaporation source in which an electron beam is deflected at an appropriate angle, guided onto the evaporation material, and the beam is scanned over the evaporation material. A novel electron impact heating evaporation source is provided in which the beam C' is scanned over the evaporation material in steps, and the time and/or position of each step can be varied as appropriate.

FIG. 1 schematically shows an electron percussion evaporation source showing an embodiment of the present invention. In the figure, reference numeral 1 denotes an electron gun placed in a position not directly exposed to air, and the electron beam from the electron gun is deflected by, for example, 180 degrees by the magnetic field of a permanent magnet 2, and the evaporation material 4 placed in a pot 3 is deflected by 180 degrees. be led upwards. 5a
, 5b, 5c.

. . . is a substrate on which a film is formed by the vapor of the material 4. 6X and 6Y are an X-direction deflection coil and a Y-direction deflection coil, respectively, and the beam is scanned over the material 4 by turning the deflection coils. The electron gun 1 to deflection coils 6X and 6Y described above are arranged in a vacuum container. 7X and 7Y are X-direction and Y-direction digital running M signal generators, respectively, and their respective output signals are sent to the deflection coils 6X and 6Y via DA converters 8X and 8Y and amplifiers 9X and 9Y. Reference numeral 10 denotes a step position setting device, which sets the position of the beam on the material 4. Reference numeral 11 denotes a dwell time setter for setting the length of each step of the digital scanning signal. Incidentally, the stagnation time setting device 11 and the step position setting device 10 may be controlled by a digital controller 12 such as a digital computer as shown in the figure.

First, assuming that the shape of the beam is not distorted at all on the evaporation material, and that the scanning direction of the beam is not distorted at all, the beam is shaped like Pl (Xl, Vl), Pg on the evaporation material as shown in Fig. 2.
(X2.V2'), Pa (X3, V3 >,
P4 (X4, V4)--... The digital signal (Fig. 3 (a>, (
b) Reference). For that, step position setter 1
0, a command such that the height between each step of each digital scanning signal in the X direction and Y direction is all equal, and each step width of each digital scanning signal in the X direction and Y direction from the stagnation time setting device 11. For each command such that all are equal,
direction, ) is sent to the one-way digital scanning signal generators 7X and 7Y. The X-direction digital scanning signal generator 7x generates a digital scanning signal as shown in FIG. 3(a) based on the command, and the Y-direction digital scanning signal generator 7Y generates a digital scanning signal as shown in FIG. 3(a) based on the command. A digital scanning signal as shown in b) is generated and sent to the X-direction deflection coil 6X and Y-direction deflection=1 coil 6Y, respectively.

In this way, the scanning trajectory of the beam on the evaporated material,
Each position of evaporation material (P+, Pg, Pa,...)
The scanning locus of the beam is determined by placing a fluorescent screen in place of the evaporated material 4, scanning the electronic beam over the fluorescent screen according to the digital scanning signal, and observing the progress of the beam. Observe the scanning trajectory.

Further, the melting condition of each position of the evaporation material 4 is determined by scanning the material according to the digital scanning signal and determining the melting condition of each position (
P+, Pg,...) [Actually observe how the monthly interest rate changes. Then, based on the observation of the scanning locus of the beam, the height of each step of the digital scanning signal is controlled by the step position setting device 10, and each position (P+, Pg, . . . ) The width of each step of the digital scanning signal is controlled by the dwell time setter 11 based on the observation of the melting condition of the material. For example, as shown in FIG.
, P4, Ps, Pg, P7, Pa
, )... without moving P+ ', Pg.

Pa, P4, Ps, Pg, P7, P8'...
, the step position of Pl in the digital scanning signal shown by the solid line in Fig. 5 @ (Xl, Vl) signal becomes P
P so that the step position (Xo, V2) signal is 1".
The step position (x B , V l ) signal of a is P,
A command is sent from the step signal setter 10 to the digital scanning signal generators 7X and 7Y in the X and Y directions so that the step position (X7.l/2) signal of b is obtained, and the average melting at each position on the material is If position P4 melts only 2/3 of the average for one step, and position Ps melts twice as much as the average, then the step position of P4 in the digital scanning signal shown by the solid line in Fig. 5 ( Send a command from the dwell time setter '11 to the X and Y direction digital scanning signal generator so that the step width of xa, y4) becomes 1.5 times, and the step width of Ps becomes 0.5 times. . Then, the signals from the digital signal generator for the X, )'7j directions are shown in FIG. 5(a).

(1)) The signal has a waveform as shown by the broken line, and as a result, the beam moves to a predetermined position (P+, P2, Pa,
P4, Ps, P6. P7. Pa,=1, and in addition, it stagnates at 1.5 times the average at position P4, and stagnates at 1X2 times the average at position P5, so that the melting of the material at each position on the material becomes uniform. Therefore, since the evaporated portion of the evaporator material 1 does not change over time, the state of the material deposited on the substrate does not change.

Also, the evaporated material will be used effectively.

In the above embodiment, the step position and step time are controlled, but if any one of the controllers is
The roll also increases the 4T effect compared to the conventional method.

Also, according to the present invention, it is very effective because the beam can be stagnated at any arbitrary position for any time.For example, when melting an evaporation material made of two materials, the part to be melted and the part to be melted depend on the material. Control the ratio,
Can evenly melt circular materials.

[Brief explanation of drawings]

FIG. 1 is an electron impact heating evaporation source showing an embodiment of the present invention, and FIGS. 2 to 5 are diagrams for supplementing the detailed explanation of the present invention. 1: Electron gun, 2: Permanent magnet, 3: Crucible, 4: Evaporation material,
=6X: X-direction deflection coil, 6Y: YZJ-direction deflection], 7X: X-direction digital scanning signal generator, 7Y: Y-direction digital scanning signal generator, 10 two-step position setter, 11: Stagnation time setter . Patent applicant JEOL Ltd. Representative Ito-husband Figure 3

Claims (1)

[Claims] The electron beam is deflected at an appropriate angle and guided onto the evaporation material, and placed in an evaporation source J3 that scans the evaporation material with the beam, so that the beam scans the evaporation material in steps. , an electron impact heating evaporation source in which each step time and/or each step position can be varied as appropriate.