Hitachi, Ltd.

Hiroshi Umezaki

Yutaka Sugita

Ryo Suzuki

Teruaki Takeuchi

Naoki Koyama

Masatoshi Takeshita

Norikazu Tsumita

Nagatugu Koiso

Hirozi Yamada

Hideki Nishida

Tadashi Ikeda

Naoki Kodama

Ryo Imura

Katsuhiro Kaneko

Fusaji Shoji

Takashi Toyooka

Haruhiko Matsuyama

Yooji Maruyama

Youji Maruyama

Masatake Takahashi, Deceased

Yoozi Maruyama

The inclination angle, in the conductor pattern end portion of a magnetic bubble memory element having a bubble diameter of up to 1.2 .mu.m, can be remarkably reduced by employing a polymer resin, having fluidity in a curing process, as the insulation film under the conductor pattern, so that the transfer margin is greatly improved.

Magnetic bubble memory element

A hybrid magnetic bubble memory device comprising soft magnetic material propagation tracks and ion-implanted propagation tracks. In the soft magnetic material propagation track region, a layer made of a heat-resistant polymer was provided as an interlaminar insulating layer between a conductor and a pattern of a soft magnetic material. An insulator film made of a heat-resistant polymer was provided on the pattern made of a soft magnetic material. A passivation film made of an inorganic material was provided on the ion-implanted propagation tracks and the insulator film made of a heat-resistant polymer.

Magnetic bubble memory device

A magnetic bubble memory device is disclosed which is equipped with a minor loop of a magnetic bubble propagation track formed by ion implantation and a major loop or major line of a magnetic bubble propagation track consisting of a soft magnetic film and in which the thickness of an insulating film at at least the junction between the minor loop and the major loop or major line is less than the thickness of insulating film at the major line or major loop.

A method of fabricating a magnetic bubble memory device is disclosed in which ions are implanted in a desired portion of a surface region in a magnetic bubble film for magnetic bubbles to form a strain layer having a strain of about 1% to about 2.5%, a film is provided on the magnetic bubble film so as to cover the magnetic bubble film with the film and then the magnetic bubble film is annealed under predetermined conditions, thereby providing a practical magnetic bubble memory device having a large bias margin.

Method of fabricating magnetic bubble memory device

A magnetic bubble memory device comprises an ion-implanted region for information storage formed in a surface of a magnetic material layer and a permalloy transfer path formed near an ion implantation transfer path defined by the edge of the ion-implanted region for reading information from the ion implantation transfer path or writing information in the ion implantation transfer path. The ion implantation depth in a portion of the ion-implanted region near the permalloy transfer path is continuously changed to provide an inclined edge of the ion-implanted region.

Fine patterns are formed by a process wherein a workpiece is spin coated with a heat-resistant resin layer, this resin layer is spin coated with an organotitanium or titanium oxide layer, a resist pattern is formed on the organotitanium or titanium oxide layer, the organotitanium or titanium oxide layer is etched by ion etching with the resist pattern as a mask, and finally, the resin layer is etched by using the etched organotitanium or titanium oxide layer as a mask.

Process for forming fine patterns

A method of implanting a magnetic garnet film with ions is disclosed in which a covering film is provided on a monocrystalline magnetic garnet film for magnetic bubbles, and hydrogen ions are implanted in a desired portion of a surface region in the magnetic garnet film through the covering film. According to this method, it is possible to form an ion-implanted layer in which the ion concentration distribution in the direction of depth is uniform, and moreover the inplane anisotropy field in the ion-implanted layer decreases only a little with time in an annealing process.

Method of making magnetic bubble memory device by implanting hydrogen

A photomask is disclosed which is suitable for use in the one-mask method capable of forming a plurality of patterns with one exposure, and in which an opaque pattern having a predetermined form and a semi-transparent pattern having another predetermined form are formed on a transparent substrate, and the semi-transparent pattern is formed of an opaque film having a large number of fine through holes.

Photomask

A magnetic bubble memory device and a method of fabricating the device are disclosed in which a conductor pattern lies at least between a film for maintaining magnetic bubbles therein, and a soft magnetic material pattern. Further, the magnetic bubble memory device can be formed precisely without suffering from errors due to mask alignment, by employing a mask provided with a plurality of patterns which are different in transmittance.

Magnetic bubble memory device and method of fabricating the same

A method of forming a microscopic pattern wherein the object to be etched is overlaid with a film made of a material which is highly immune to etching and further provided with a reflection reducing film. Thus, the reflection of the irradiating ultraviolet rays by the underlying layer is effectively prevented.

Method of forming a microscopic pattern

A magnetic bubble memory device is disclosed in which a hardened film made of a heat-resisting highly-polymerized organic resin and having a predetermined thickness is employed for an insulating film interposed between a conductor pattern and a soft magnetic material pattern. In a conventional magnetic bubble memory device in which the above-mentioned insulating film is made of SiO.sub.2, an abrupt step is produced in the soft magnetic material pattern due to the existence of the conductor pattern beneath a portion of the soft magnetic material pattern, and the margin of bias magnetic field is thereby lowered. According to the present invention, the step is reduced and smoothed, and thus the lowering of the margin can be prevented.

Growing community of inventors

Koganei, Japan

Hiroshi Umezaki