JPS60241211A - Forming method of transfer path for magnetic bubble - Google Patents

Abstract

PURPOSE:To improve uniformity in a film surface by repeating a process, in which a mask shielding implanting ions is formed on a magnetic garnet film, ions in quantity less than the last quantity of ions implanted are implanted and the ions are annealed, twice. CONSTITUTION:Ions are implanted to a magnetic garnet film, thus forming a magnetic bubble transfer path for a magnetic bubble element. A process in which a mask shielding implanting ions is shaped on the magnetic garnet film, ions in quantity less than the last quantity of ions implanted are implanted and the ions are annealed is repeated at least twice at that time. Accordingly, an X-ray diffraction peak is sharpened remarkably, thus improving uniformity in a film surface.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for forming a magnetic bubble transfer path on a magnetic garnet film by ion implantation.

(Prior Art and its Problems) In conventional ion implantation to form a magnetic bubble transfer path, helium ions, neon ions, hydrogen ions, etc. are used as implanted ion species.

However, it has been found that when the ion implantation amount is increased so that the ion implantation layer becomes sufficiently strained and the anisotropic magnetic field changes, the diffraction waveform obtained by the XIIJ two-crystal method tends to become purified after annealing. Ta. This means that the non-uniformity of strain in the ion-implanted layer increases, which has an adverse effect on device characteristics.

(Object of the Invention) The present invention was made in view of the above points, and its purpose is to form a magnetic bubble transfer path by ion implantation, even when an implanted layer with a sufficiently large amount of lattice strain is formed. It is an object of the present invention to provide a method for forming a magnetic bubble transfer path that does not increase the non-uniformity of strain in an injection layer and maintains good characteristics.

(Structure of the Invention) That is, the present invention provides a method for forming a magnetic bubble transfer path of a magnetic bubble element formed by implanting ions into a magnetic garnet film. 2. A method for forming a magnetic bubble transfer path, characterized in that the steps of implanting ions in an amount smaller than the final ion implantation amount and annealing are repeated at least twice.

(Detailed explanation of the configuration) When implanting a certain amount of hydrogen ions, helium ions, or neon ions, the implantation process is not implanted all at once, but the implantation process is interrupted at least once during the implantation, and the garnet film is annealed and then restarted. inject.

The final annealing process after a certain amount of implantation is completed may be the same as the conventional process.

The mechanism by which the uniformity of the implanted layer is improved by annealing at least once before a certain amount of implantation is completed is not necessarily clear, but it is thought to be as follows.

By interrupting the implantation and annealing before the required implantation amount is reached, the occurrence of stacking faults that would occur when the required implantation amount was continuously implanted is suppressed, and furthermore, the damage to the crystal caused by the previous implantation is suppressed. Partially recovered by annealing, the crystal properties of the implanted layer do not remain fatally damaged due to stacking faults, and only crystal lattice distortion due to relatively minor damage remains.

By implanting ions into the garnet film in this state again and then annealing it in the same way as before, it is possible to form an implanted layer that suppresses deterioration of the crystallinity of the implanted layer by achieving a predetermined amount of lattice strain. .

In other words, by annealing before the required implantation amount is reached, the implanted ions can be released outside the film, thereby suppressing the concentration of implanted ions within the film that occurs when the implantation amount increases. Deterioration of crystallinity can be suppressed.

(Example) The present invention will be explained in more detail below with reference to Examples.

A magnetic garnet film (YSmI, ucaBi) with a negative magnetostriction constant grown by a liquid phase method on a GGG substrate (Fe
Oe)s0□ (film thickness 1.2μm, characteristic length 13 = 0
．． 12 pm.

Saturation magnetic flux density 660 Gauss, Ku 460 (1
Acceleration energy of helium ions to 1001 (eV, dose 2.35
KeV,)''-dose 7.5 x IQ14crl and acceleration energy 25KeV, dose 5X10'nd = 3
After heavy injection, annealing in air at 400℃ for 1 hour, acceleration energy 100Kev, dose 3.13x1
0Is/d and acceleration −+− Nerky 45KeV)”
Triple implantation was performed with a dose of 1 x IQ''/all and an acceleration energy of 25 KV and a dose of 6.7 x 10 I4/c, and annealing was performed again at 400°C in air for 1 hour.

FIG. 1 shows the diffraction waveform of X# when the amount of lattice strain in this ion-implanted layer was measured by the X# two-crystal method. As a comparative example, helium ions were accelerated on a magnetic garnet film with the same characteristics at an energy of 100 Ke V and a dose of 5.48 x 10".
/ m and acceleration energy 4sKeV.

Dose: 1,75 x 10"lcI & acceleration energy: 25KeV, )"-Xtl, 17xlO"7m
Figure 2 shows the X# diffraction waveform when the amount of lattice strain was measured by the X-ray crystal method after annealing at 4QO 0 C in air for 1 hour.

(Effects of the Invention) As is clear from the comparison with Example 7 and Comparative Example, the present invention results in significantly sharper X-ray diffraction peaks and improved in-plane uniformity of the film.

In addition, the characteristic value lattice strain amount of the injection layer and the amount of change in the anisotropic magnetic field can obtain values similar to those in the conventional comparative example,
The transfer characteristics of the bubble transfer path are also improved, which greatly benefits manufacturing.

[Brief explanation of drawings]

FIG. 1 is an X# diffraction waveform diagram obtained by the method of the present invention. FIG. 2 is an Xa diffraction waveform diagram obtained by the conventional method. Figure 1 -0,3-0,2-0,10 Figure 7I-2 10, 3 -0.2 -0.1 0 Eighty (degrees)

Claims (1)

[Claims] In a method for forming a magnetic bubble transfer path in a magnetic bubble element formed by implanting ions into a magnetic garnet film, a mask is formed on the magnetic garnet film to shield implanted ions, and then an amount smaller than the final amount of ions is implanted. A method for forming a magnetic bubble transfer path, characterized in that the steps of ion implantation and annealing are repeated at least twice.