US3351731A

US3351731A - Method and apparatus for treating material with a charged beam

Info

Publication number: US3351731A
Application number: US313665A
Authority: US
Inventors: Tanaka Kazumitsu
Original assignee: Jeol Ltd
Current assignee: Jeol Ltd
Priority date: 1962-10-23
Filing date: 1963-10-03
Publication date: 1967-11-07
Anticipated expiration: 1984-11-07
Also published as: GB980600A

Description

un-nnvnl uuul 1957 KAZUMITSU TANAKA METHOD AND APPARATUS FOR TREATING MATER 3,351,731 IAL WITH A CHARGED BEAM 2 Sheets-Sheet 1 Filed Oct. 5. 1963 J II INVENTOR. K 7622" a.

1967 KAZUMITSU TANAKA 3,35

METHOD AND APP ARATUS FOR TREATING MATERIAL WITH A CHARGED BEAM Filed Oct. 5, 1963 2 Sheets-Sheet 2 I I I I l I n i 8 INVENTOR.

BYKEMQJ Fig. I0 v4 401- United States Patent 3,351,731 WTHOD AND APPARATUS FOR TREATING MATERIAL WITH A CHARGED BEAM Kazumitsu Tanaira, Tokyo, Japan, assignor to Nihon Denshi Kabushiki Kaisha, Tokyo, Japan, a corporation of .lapan Filed Oct. 3, 1963, Ser. No. 313,665 Claims priority, application Japan, Oct. 23, 1962, 37/ 47,304 9 Claims. (Cl. 219-69) ABSTRACT OF THE DISCLOSURE An apparatus and method for curvilinearly treating materials with a charged beam by applying a magnetic or electrostatic field to the material to be treated so as to deflect the charged beam within the material to be treated.

This application relates to method and apparatus for treating material with a charged beam and more particularly to method and apparatus whereby curved cuts, grooves and bores can be made by treating material with a charged beam. In prior methods and apparatus for treating material with charged beams, it has been possible to make only straight cuts or grooves. This is due to the fact that in the use of prior apparaus for treating materials with charged beams, the beams passed through the material in straight lines only. I overcome this limitation by producing a field capable of deflecting charged particles in the material being treated while it is subjected to the charged beam. The deflecting field deflects the particles in the charged beam and causes them to follow a curved path within the material being treated.

I also provide proper operating conditions within the material treating zone by subjecting the material being treated to intermittent pulses of the charged beam.

The charged beam consists of charged particles, for example, an electron beam or an ion beam. The charged particle deflecting field may be a magnetic field, an electrostatic field, or a combination of both.

In the accompanying drawings, I have illustrated certain presently preferred embodiments of my invention in which:

FIGURE 1 is a diagram illustrating the principle of my invention;

FIGURE 2. is a schematic diagram of apparatus used for carrying out my invention;

FIGURES 3-7 inclusive illustrate articles formed by treating materials in accordance with my invention;

FIGURE 8 is a schematic diagram partially illustrating a modification of apparatus for carrying out my invention;

FIGURE 9 is a section along the lines IX-IX in FIGURE 8; and

FIGURE 10 is a schematic diagram illustrating a portion of a second modification of apparatus used for carrying out my invention.

Referring to FIGURE 1 of the drawings, material 1 to be treated is placed between

poles

2 and 3 of an electromagnet, the polarity of the poles being indicated by the letters N and S. An electron beam 4 is focused on the material, and the beam is deflected within the material in a direction at right angles to magnetic flux 5 developed by the poles. The electron beam is thereby curved in its passage through the material and, by controlling the amount of deflection of the electron beam, cuts and grooves having any desired curve can be made in the material by bombardment by the electron beam.

FIGURE 2 is a schematic diagram of apparatus for carrying out my invention. The material 1 to be treated is placed between the

pole pieces

2 and 3 of an electro- 3,351,731 Patented Nov. 7, 1967 magnet on a movable support 11, and an electron beam 4 is focused so that the point of minimum cross section of the beam falls on the surface of the material 1. The electron beam is emitted from an electron gun 7 having a cathode 8 and an anode 9 and is focused by a condenser lens 10.

The

magnetic polepieces

2 and 3 are energized by coils 12 and 12' and they are connected by a yoke 13 which provides a magnetic flux return path.

A tubular shield 14 of material having high magnetic permeability surrounds the path of the electron beam 4 and protects the beam from disturbance by magnetic flux from the

poles

2 and 3, yoke 13 and coils 12 and 12' during its passage from the electron gun 7 to the material 1.

The interior of the entire apparatus is maintained under a high vacuum, an outlet 15 being provided for exhausting the electron emitting system A and an outlet 16 for exhausting the treating chamber B.

When the electron gun 7 is energized to make cuts or grooves in the material 1 being treated by means of the electron beam 4, the

magnetic poles

2 and 3 are also energized to create a magnetic field passing through the material 1 in a direction at right angles to the axis of the electron beam 4. The effect of the magnetic field is to deflect the electrons in the electron beam in a direction at right angles both to the direction of the magnetic field and to the direction of the electron beam. The electrons in the electron beam therefore follow a curved path through the material being treated. The amount of the curvature can be controlled by regulating the speed of the electrons and by regulating both the strength and direction of the magnetic flux created in the material by the

pole pieces

2 and 3.

FIGURES 3-7 inclusive illustrate different cuts or grooves which can be formed in the material by my method and apparatus. The article shown in FIGURE 3 was formed by irradiating the material 1 with an electron beam, creating a magnetic field flowing through the material and at the same time moving the material on the support 11 in the direction of the arrow 17. The material was cut into two pieces, 1 and 1', each having a uniformly curved surface.

In the article shown in FIGURE 4, a groove 18 was formed in the same manner as the cut was made in the article shown in FIGURE 3. The article shown in FIG URE 5 was made by a cut similar to that made in the material shown in FIGURE 3, and a second out similar to the first cut but curving in the opposite direction. The oppositely directed cut was made by reversing the direction of the magnetic field created by the

pole pieces

2 and 3, the direction of the field being changed by reversing the direction of the current flowing through the coils 12 and 12'.

FIGURE 6 shows a bore having a single entrance and two outlets 19 and 19' branching from the bore which has been cut in the material 1. In the article shown in FIGURE 7, a groove 18 has been out having a straight entrance and a curved outlet, the curve in the outlet having been formed by varying the strength of the magnetic field, the polarity of the field remaining constant.

FIGURE 8 is a schematic diagram showing another form of my invention in which several magnetic fields are created in the material being treated by using two or more pairs of magnetic pole pieces of the same or opposite polarity. In the apparatus illustrated in FIGURE 8, the pole pieces 2-3 and 2"3 have the same polarity, and the pole pieces 2'3' are of opposite polarity so that a bore 19 cut in the piece by the electron beam 4 will be curved as shown in FIGURE 9.

FIGURE 10 illustrates diagrammatically a further modification of my invention in which the axis of the electron beam forms with the direction of the magnetic flux 5 passing through the material an angle of less than 9t). Due to the interaction between the electrons in the electron beam and the magnetic flux, a spiral bore is cut in the material.

When cuts or grooves are being formed in material as described above, molecules in the portions of the material being treated may vaporize, be bombarded by electron beams, and thereby become ionized. These ionized molecules will be in the path of the electron beam and may disturb the direction of the beam so that the desired shape of a cut or groove is not obtained. To avoid this difliculty, I operate the electron gun intermittently so that the material being treated receives intermittent pulses of the electron beam. During the times that the electron beam is not treating the material, the system used to maintain a high vacuum in the apparatus draws away from the material the ionized molecules so that when the beam is energized, it has a clear path to the material being treated. Pulsing of the electron gun can be accomplished in a number of ways, for example, by providing periodically a negative voltage to a grid forming part of the electron gun.

FIGURES 3-7, 9 and 10 show only a few of the many shapes of cuts and grooves which can be formed in material by bombardment by a charged beam when a magnetic or electrostatic field is maintained in the material in accordance with my invention. Any desired shape or configuration of cuts, grooves, or bores can be obtained by adjustment of the speed of the electrons in the electron beam, adjustment of the angle between the electron beam and the magnetic or electrostatic field, and by adjustment of the strength and polarity of the magnetic or electrostatic field. My invention is particularly useful in the manufacture of miniaturized parts.

While I have described a presently preferred embodiment of my invention, it is to be understood that it may be otherwise variously embodied within the scope of the appended claims.

I claim:

1. A method of curvilinearly treating material with a charged beam which comprises,

(A) focusing a charged beam onto the material, and

(B) applying to the material a field capable of deflecting charged particles within the material, the direction of the deflecting field being at an angle to the direction of the charged beam so as to curvilinearly treat the material.

2. A method of treating material with a charged beam as described in claim 1 and including the step of varying the strength of the charged particle deflecting field.

3. A method of treating material with a charged beam as described in claim 1 and including the step of changing the polarity of the charged particle deflecting field.

4. A method of treating material wtih a charged beam as described in claim 1 and including the step of impinging thec harged beam onto the material in intermittent pulses.

5. Apparatus for curvilinearly treating material wtih a charged beam which comprises,

(A) a source of charged beams,

(B) a condenser lens for focussing charged beams from said source onto material to be treated, and

(C) means for applying to the material to be treated a field capable of deflecting particles within the material, the direction of the deflecting field being at an angle to the direction of the charged beams whereby the beam curvilinearly treats said material within the material.

6. Apparatus for treating material with a charged beam as described in claim 5 and including means for changing the strength of the deflecting field.

7. Apparatus for treating material with a charged beam as described in claim 5 and including means for changing the polarity of the deflecting field.

8. Apparatus for treating material wtih a charged beam as described in claim 5 and including means for operating said charged beam source in intermittent pulses.

9. Apparatus for treating material with a charged beam as described in claim 5 and having a magnet for creating the deflecting field.

References Cited UNITED STATES PATENTS 2,267,752 12/1941 Ruska et a1 21969 X 2,932,588 4/1960 Frank. 3,033,974 5/1962 Schleich et a1. 219-1 17 3,151,231 9/1964 Steigerwald 219-121 RICHARD M. WOOD, Primary Examiner.

R. F. STAUBLY, Assistant Examiner.

Claims

1. A METHOD OF CURVILINEARLY TREATING MATERIAL WITH A CHARGED BEAM COMPRISED, (A) FOCUSING A CHARGED BEAM ONTO THE MATERIAL, AND (B) APPLYING TO THE MATERIAL A FIELD CAPABLE OF DEFLECTING CHARGED PARTICLES WITHIN THE MATERIAL, THE DIREC-