DE1519842B2 - Ferromagnetic memory and method and device for its production - Google Patents

Description

A. Epitaxial application of a first, monocrystalline ferrite layer,

B. Application of two groups of polycrystalline conductors,

C. epitaxial application of a second monocrystalline ferrite layer,

characterized by the following process steps:

Procedure section A:

a) a monocrystalline carrier made of MgO, MgAl ₂ O ₄ or Al ₂ O ₃ is heated to about 100O ^{0 C in a chamber,}

b) elsewhere in the chamber are halogens of iron and another Element of a group consisting of Mn, Ni, Fe, Mg and Co, evaporates,

c) the vaporized halogens are in a carrier gas consisting of approximately 140 liters / hour of helium and 280 liters / hour of argon transported to the heated carrier,

d) water vapor and approximately 2.3 liters / hour of oxygen are in a carrier gas, consisting of a mixture of

35

40

45 transports approximately 170 liters / hour of helium and 85 liters / hour of argon to the carrier,

e) cooling the carrier and the epitaxially grown first monocrystalline ferrite layer;

Procedure section B:

f) applying a first group of parallel polycrystalline conductors,

g) applying an insulating material to at least some of the conductors,

h) Applying a second group of parallel polycrystalline conductors that form the first Cross conductors, and those of the first conductors isolated by the insulating material are,

Procedure section C:

i) reheating of the carrier provided with the first ferrite layer and the conductors in the chamber to a temperature of about 1000 ^° C.,

j) to 1) applying the second ferrite layer by repeating process steps b) to d),
m) cooling the ferromagnetic memory.

5. Apparatus for performing the method according to claim 4, characterized by a T-shaped chamber (1) which has a gas inlet (3) at one end of the cross part (4), a gas outlet (18) at the other end of the cross part (4) and a second gas inlet (2) on the Has the base of the upright chamber part,

with a first heating element (7) on the cross part (4), which heats this chamber part and the material located therein,
with a holder (8) for carrier pieces (10), which is arranged in a reaction zone within the cross part (4) between the upright chamber part and the gas outlet (18) and carries carrier pieces (10) on which the deposition takes place,
with a number of melting pots (5) which contain halide compounds and are arranged at a distance from one another along the upright chamber part and within the same, and
with a number of individually controllable heating elements (7) on the upright chamber part, which heat each melting pot (5) to a predetermined temperature and thus control the amount of each halide compound which is introduced into the reaction zone.

6. Apparatus according to claim 5, characterized in that the carrier pieces (10) only with the edges in the longitudinal direction of the pipe rest on the holders (8).

The invention relates to a ferromagnetic memory with a first group arranged in parallel

3 4

polycrystalline conductor and a second group of the same current strength a higher and more uniform

Inductance that is arranged in parallel and crosses the first conductors can be produced than with a polycrystalline one

polycrystalline conductor, the two conductor groups receiving device.

isolated from each other in two mutually parallel When using a single-crystalline ferrite

Arranged levels and from a common, one 5 reduces the current intensity, the z. B. is necessary

lumpy ferrite bodies are encased; the invention to store information in a memory

also relates to a method and apparatus for erasing or erasing since the ferrite is oriented to be

Manufacture of the ferromagetic memory. is easily magnetizable. It also reduces

The poly-monocrystalline ferrite previously used for storage purposes reduce the fluctuations of the minimum

Crystalline ferrite storage units have, due to their critical storage current strength, from storage space to storage

stable construction has a number of properties that take up space.

z. B. in terms of their constancy and the magnetization purpose of producing ferromagnetic memory availability in a given crystallographic series is known to be on a single crystal support processing and its power consumption do not always satisfy a first monocrystalline ferrite layer epitaxially. In a polycrystalline material e.g. B. 15 can grow, on this a first group parallel the direction of easy magnetizability does not apply for polycrystalline conductors, every conductor minalle Crystals are aligned in the same way and are therefore at least partially covered with an insulating material Magnetization devices, statistically distributed. sees a second group of parallel polycrystalline

It was therefore the task of the ferrite body conductors that cross the first conductor and from these

to find a material that is insulated by the insulating material in the above, applies, and

wrote properties the polycrystalline ferrite - a second single crystalline ferrite layer on top of the first

memory surpasses. allows monocrystalline ferrite layer to grow for so long

This problem is solved by the fact that the ferrite until it envelops the polycrystalline conductor,

body is monocrystalline and with regard to the ladder an earlier attempts according to these

Has predetermined crystal orientation. However, as already noted, in the end, 25 struggles

Earlier attempts to embed a polycrystalline material in a monocrystalline material or to encapsulate the poly-polycrystalline deposit and crystalline material through the monocrystalline material therefore also had the task of enclosing a suitable one to find a polycrystalline deposition method for the storage according to the invention on the surface of the encapsulated poly-ferromagnetic memory,
crystalline material. In effect, this object was achieved by encapsulating the one polycrystalline material in a polycrystalline growth rate of the second deposit surrounding the conductors. Consequently, the advantages of single-crystal ferrite layer of being embedded or encased in a single crystal have been limited in such a way that this layer is preferably not recognized on the first single-crystal. 35 crystalline ferrite layer epitaxial, grows up, however

For example, as the name suggests, the deposition of polycrystalline ferrite on the material of a single crystal has a uniform crystal-polycrystalline conductor,
Linen structure and has through its entire structure. Advantageously, the second monocrystalline properties can be maintained throughout. Ferrite layers are also allowed to grow until the properties of one production run to the polycrystalline conductor remain constant at least at the intersections of the others. The opposite is true for polypoints of the two groups of leaders enveloped. A crystalline production aisles too. It is difficult, in a suitable process for the production of the invention polycrystalline substances essentially identical ferrite body according to z. B. from three process properties. You can also pass your own sections:
predict shafts of single crystals better, and they 45
are therefore easier to control. A. Epitaxial application of a first, single-crystal

Single crystals, which consist of magnetic substances, linen ferrite layer,

are anisotropic and can easily be applied in a given B. application of two groups of polycrystalline

be magnetized in the crystallographic direction. Ladder,

Monocrystalline substances can therefore be used as magnetic 50 C. epitaxial application of a second monocrystalline

Memory are used. linen ferrite layer,

In substances that consist of a single crystal shows

In contrast to polycrystalline material, the Rieh- and the device for carrying out the Vertung the easy magnetizability in certain and driving can consist of a T-shaped chamber, known directions and is evoked by an electrical 55 being those belonging to the three procedural stages magnetic field strength better before the process steps and the structure of the T-shaped visibly rotated. Chamber according to the description and the patent

Since the monocrystalline material takes place in its entirety claims.

is more similar in its magnetic properties The ferrite single crystal can advantageously consist of a lower field strength (Me "+ Fe) ₂ O ₄ than polycrystalline material, for magnetization 60, in which Me" and Me "less required. The saturation of the monocrystalline mass, an element consisting of Li, Mg, Fe, Cu, Zn, Cd, Al, terials, can be achieved more easily than is the case with poly- Cr and Ti.
crystalline substances, and therefore less electricity is required. The ferromagnetic memory according to the invention. For example, if the material 65 can be made by using the poly to make the core of a miniature choke crystalline material and the single crystal material coil by encapsulating a polycrystalline conductor as a substrate in a chemical, with a single crystal device with steam chamber at a short distance from each other

are arranged so that if the crystal structure of the single-crystal carrier material is that of the deposition reaction product is similar, the single crystal support is the preferred deposition site. It a critical reaction rate can be set so that the entire deposit on the monocrystalline carrier material and therefore no polycrystalline deposition on the polycrystalline Material takes place. The critical reaction speed can thereby be determined that the deposit is observed in the vicinity of the substrate. The speed of response can be changed by changing the flow rate of the gases of the reacting Elements is changed until a growth rate of the single crystal is reached which outweighs the rate of formation of crystallization nuclei.

A critical reaction rate can be for any material that is deposited and for anybody Carrier to be determined. Each combination of the deposited material and the support material has one other critical response rate. That is, any combination of deposited material and substrate has a growth rate at which the deposition occurs in a single crystalline manner instead of polycrystalline. Therefore, no material is deposited on a polycrystalline material that is present in the Reaction chamber may be present, as this would require the formation of crystallization nuclei. Although the polycrystalline material is on the way of crystal growth of the deposited material is housed, the crystal structure of the deposit is exclusively due to the monocrystalline Carriers are affected, and the polycrystalline material becomes from the single crystalline deposit without polycrystalline Deposit inclusions embedded or enclosed.

In view of the fact that the nucleation of a deposition material is essentially zero can decrease when the growth of the material is reduced is from the above it can be clearly seen that the rate of deposition must be slower than the critical reaction rate.

The ferromagnetic memory according to the invention can also be produced by first the single crystal material is deposited on a single crystal support and then the polycrystalline material is deposited. After the deposition of polycrystalline material on a predetermined one Place on the single crystal material, the single crystal deposition continues until the polycrystalline Material is embedded or enclosed as desired.

The ferromagnetic memory can also thereby can be made to produce a ferrite single crystal body which is magnetically anisotropic and lightweight can be magnetized in a given crystallographic direction. In one embodiment of the ferromagnetic memory, a number of electrical conductors are crossed and insulated in the Ferrite body embedded and essentially surrounded by it, so that a magnetic alignment in the ferrite is obtained by sending an electric current through one or more conductors.

In another embodiment of the ferromagnetic memory, after the electrical Conductors have been placed on the single crystal ferrite surface and one selected in advance Have direction with respect to the ferrite crystal and are approximately isolated at the crossing points, additional monocrystalline ferrite material deposited over it, initially at the crossing point in monocrystalline Encapsulate ferrite material. For example, the direction of the ladder can be chosen to be one Crystal direction be parallel or perpendicular, or form an angle with it.

ίο The ferrite body can be formed in that selected metal halides and water vapor convert to the ferrite material epitaxially in a to be deposited in a preselected crystallographic form.

In the following description, with reference to the drawings, the manufacture of a ferromagnetic memory by encapsulating polycrystalline conductors in a single crystalline ferrite material explained:

Fig. Figure 1 is an illustration of an apparatus used to convert polycrystalline material into single crystal Embed or enclose material to the ferromagnetic memory according to the invention to surrender.

F i g. Figure 2 is a cross-sectional view of the device of Figure 2. 1 along the line AA in FIG. 1. F i g. 3 is a cross section of part of the ferromagnetic memory according to the invention. F i g. Fig. 4 is a perspective view of a storage system using a magnetic memory according to the invention.

F i g. Figure 5 is a cross-sectional view of the memory showing the insulation between the conductors. According to FIG. 1, the device has a chamber 1, which is preferably a. T-shaped, further inlet means 2 for blowing gases into one end of the chamber 1 and an outlet 18 at the other end of the part 4. The cross part 4 is surrounded by a heating element in order to regulate the temperature in the part 4. Inside the chamber 1 a number of melting pots 5 are fixed spatially separated from one another on a central support rod 6, but they can be held in their central position by any other known means. On the outer surface of the chamber 1 there is a number of heating elements 7 which are arranged so that each melting pot 5 surrounds a heating element 7. Each element 7 can be controlled individually so that the area in which each melting pot is located can be heated to a preselected temperature. In the cross part 4 there is a quartz holder 8 which carries carrier materials or crystals 10. The crystals 10 are arranged along the cross part 4 from a point where the chamber 1 enters the cross part 4 towards the outlet opening so that each is exposed to a mixture of gases flowing in from the inlets 2 and 3. The inlet 2 is connected to a non-illustrated generation point for a dry mixture of He and Ar. The inlet 3 is connected to a generation point, not shown, in which helium, argon and oxygen are passed through water in order to produce a mixture of noble gases, oxygen and water vapor, ie He, Ar, O ₂ and H ₂ O.

The carrier materials 10 on which the ferrite crystal is deposited or grows consist of a material whose crystalline structure is similar to that of the material to be deposited. Can be used as a carrier

7th 8th

MgAl ₈ O ₄ , Al ₂ O ₃ and other substances that use the formula, however, gold is because of its over-

Me'Me " ₂ O _4. Excellent electrical properties are preferred.

The carrier material is not restricted to the use of These conductors are preferably restricted to the crystal spinel materials mentioned here. plane aligned in order to magnetizations along the materials which are used for the production of the ferromagnetic 5 different directions (cf. S with memory, are only used by the Wi jn, Ferrites, John Wiley & Sons 1959).
Crystal orientation of the deposited material and after the first row of conductors has been deposited, limits the type of deposit. If the material is insulating material in a selected pattern z. If deposited, for example, by chemical evaporation processes to cover parts of the first row of conductors, many different substances can be deposited. Insulating materials such as Al ₂ O ₃ and BaF ₂ can be stored. Then a substrate is selected with a crystal orientation that can be deposited on it by ordinary deposition processes. Thereafter, a single crystal is allowed to be placed in or stored. The deposition of several conductors, which form a second row of conductors, in rate depends on the type of support and the vacuum deposited so that they form the first row under material. 15 cross at a certain angle and through the

The carrier material 10 is isolated from the insulating materials deposited in the interior of the cross

partly 4 carried by a holder 8 and a ferrite are.

layer can be deposited as it is below in After the rows of conductors with the appropriate insulation is described. deposits have been deposited at each intersection,

The starting materials 11 for the formation of the ferrite ab- ao the carrier is preferably housed in the chamber.

Storage on the carrier 10 are housed in containers 5, and a second ferrite body is on these

and are deposited through the existing ferrite layer and around the conductor until it evaporates,

different heating elements 7 heated. The starting point around at least the crossing points of the rows of ladders

substances that are housed in the containers 5 to be enveloped with the monocrystalline ferrite mass,

can Me'X _a , Me "X" or a mixture of both 35 Of course, the entire conductor can also be encased

being, where Me 'and Me "are the ones given above.

have meaning and X is a halogen (F, Cl, Br or J) It can also be advantageous in some cases provided that one of Me 'or Me "is Fe rather than a number of conductor arrangements or and the index "α" is either 1, 2, 3 or 4, depending on the series, to be embedded or enveloped, a single one the valence of the cation. At the same time to cover with the top row of 30 conductors and then a second row Heating of the material 11 will deposit the above-described and envelop them. In this Ausbenen Carrier gases through inlets 2 and 3 would introduce single crystalline ferrite through the conductors, separate rows, whereas the previous one

The following reaction rinds the rows of conductors on the surface of the guide through an insulating

Carrier 10 instead of a ferrite film on the MgO 35 material, which is different from ferrite, separated

To deposit crystals of the carrier: would.

Me'X ₂ + 2Me "X" + 3H ₂ O + 1 / 2O ₂ + noble gases .. ^F j S- }. * ^Ι « ^M _T Cross-sectional view of the chamber,

τ. * Ά * " , c ^", / TTTv, CJi the more clearly the position of the holder 8 and the crystals

■ -> Me (Me + Fe) ₂ O ₄ + 6HX + noble gases _{10 inside the K} | _{always zdgt the u} ^ _{Qr 8 will}

The term "ferrite" as used here, 40 appropriately shaped so that it relates as little as possible to compositions that only consist of the gas admission to the top and bottom and to the iron oxide or of an iron oxide in chemical side surfaces of the Carrier 10 disabled. In the embodiment shown in connection with at least one other metal oxide, the holders are semi-existent in order to form a magnetic material. formed arched. Parts of the holder jump. Therefore, the term Me '(Me "+ Fe) ₂ O ₄ 45 refers to the support pieces before, and the support pieces 10 generally refer to these ferrite materials without a need only with the necessary reference in the longitudinal direction of the tube Stoichiose edges on the holders 8. This results in a metric or empirical composition. This is achieved that the underside of the carrier mostly ferrites, which are of interest to the trade, is kept free for the unhindered addition of one or two metal oxides in chemical 5 ° occurs the gases reacting with the carrier pieces.
Connection with iron oxide. Therefore, the figures in FIG. 3 is a cross-section of an encapsulated ferritic preferably those shown for commercial conductors. As shown therein, the interesting and small coercive field strengths are the layer 12 a is the first deposition layer of the ferrite, ie MgFe ₂ O ₄ , ZnFe ₂ O ₄ , CuFe ₂ O ₄ and is on the carrier 13, the conductor 14 represents one of the compositions of these compounds. Other fer- 55 conductors of a row, while the second row of conductors ritmaterial can run perpendicular to the conductor 14 and be used transversely in this, depending on the desired application. cut cannot be seen. The ferrite

After the first ferrite layers have formed on the material 126, the enclosure completes.
Once the carrier has deposited, the carrier is removed. A perspective view of the FIG. FIG. 3 and apparatus shown in a conventional vacuum deposition chamber 60 shows FIG. 4, which housed the ladder (not shown). In the chamber, rows 14 and 16 are arranged at an angle to one another, one or more polycrystalline conductors, showing a first order, the enclosure of which by the ferrite comprise series of parallel conductors, terminated in advance 12b. Ferrite has been deposited on a carrier in a selected direction relative to the crystal structure or substrate 13, and the conductors of the ferrite on the surface of the carrier after 65 are isolated from one another by the insulation 17,
known methods, ie by vacuum F i g. 5 is a cross-sectional view of a portion of the deposit or atomization. Electrically conductive fig. 4, which shows the insulation 17 between the conductor materials, such as gold, silver, platinum or copper, rows 14 and 16 shows.

509510/246

For this purpose 2 sheets of drawings

Claims (4)

Patent claims: 1. Ferromagnetic memory with a first group of polycrystalline conductors arranged in parallel and a second group of parallel polycrystalline conductors crossing the first conductors, the two conductor groups being isolated from one another and arranged in two mutually parallel planes and are encased by a common, one-piece ferrite body, characterized in that that the ferrite body is monocrystalline and a predetermined one with respect to the conductors Has crystal orientation. 2. A method for producing the ferromagnetic memory according to claim 1, wherein one a first monocrystalline ferrite layer is epitaxially grown on a monocrystalline carrier lets, on this a first group of parallel polycrystalline conductors applies, each conductor at least partially provided with an insulating material, a second group of parallel polycrystalline Conductors that cross the first conductors and are isolated from them by the insulating material are, applies, a second single crystal ferrite layer on the first single crystal ferrite layer so Can grow long until it envelops the polycrystalline conductor, characterized in that the The growth rate of the second monocrystalline ferrite layer enveloping the conductors is limited in such a way that that this layer preferably grows epitaxially on the first monocrystalline ferrite layer, however, polycrystalline ferrite deposition on the polycrystalline conductors is avoided will. 3. The method according to claim 2, characterized in that the second monocrystalline ferrite layer lets grow until it envelops the polycrystalline head at least at the crossing points of the two groups of conductors. 4. The method according to claim 2 or 3 with the process sections