DE2501842A1 - ELECTRICAL ELEMENT FOR CHANGEABLE ROM MEMORY MATRICES - Google Patents

Description

EI m PONT DE BEMOURS AND COMPANY 10th and Market Streets, Wilmington, Delaware 19 898, V.St ₀ A.

Electrical element for changeable ROM memory arrays

The invention relates to electrical elements with a matrix with attached contact conductors and suitable Writing and reading organs to a microprogram memory (ROM memory) for filtering out the input and output information an electronic data processing system can be combined. In particular, the invention relates to electrical elements that have the resistance of the Junction layer can be electrically changed so that a number of cascaded semiconductor devices Electricity is supplied.

The new developments in semiconductor memory technology include changeable contacts, with the help of which in a regular Semiconductor devices arranged in a matrix can be connected in series with conductors according to a planned scheme, that some devices in the matrix are active and others are not. Such a system is called a microprogram memory or ROM (read-only memory) because it is

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to sift out the input and. the output information from electronic data processing systems. The method, which consists in selectively connecting only those semiconductor devices in the matrix which are to be activated, is called writing in the ROM memory. In general, a complete, regular matrix of semiconductor devices is fabricated, even if some of the devices are not used to fabricate the desired scheme, with an interconnecting barrier compound between each semiconductor device and at least one of its complementary, heat-bondable contact conductors activated so that semiconductor devices become active in the desired scheme. As a link between the conductor and the semiconductor device, the barrier compound must be highly electrically conductive in order to avoid the accumulation of too much heat by dissipating electrical energy in the barrier layer, which would affect the packing density of the semiconductor devices per unit volume.

Elements for densely packed ROM memory arrays must have barrier layers which are either in contact with a semiconductor device when they are manufactured or by activation may have a low electrical resistance for controllable activation of the semiconductor device. the Barrier compounds must be heat-resistant at the temperatures that are usually used in order to be ohmic Alloy contacts between metallic conductors and semiconductor devices in the same or adjacent elements of a ROM memory array if the barrier layer is created before the contacts are made.

For changeable ROM memories (AROM memories) the barrier layer be able to act as a switch that controllably makes the semiconductor device active or inactive

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power. For example, it must be able to change from a low-resistance to a high-resistance state in order to control the semiconductor device to deactivate so that errors that occurred when writing to the memory can be corrected, or so that substantial changes can be made in the schema of the memory.

Switch-like devices in a previously known manner consist of mixtures of electrically conductive and insulating materials, may be used as a Barrier masses unsuitable because they do not allow electrical current regulation in a sufficiently large area, have too high an electrical resistance, easily when using the memory at ordinary temperatures jump back spontaneously from a low-ohmic to a high-ohmic state or are not sufficiently heat-resistant to the Withstand processing conditions common in microcircuit and integrated circuit technology can be applied. For example, such devices may not tolerate the temperatures at which which alloy bonding between contact conductors and semiconductor devices is usually performed, or it may be that in their electrically conductive state they have too high a resistance per contact, if a low resistance of, for example, a few ohms per contact required can be in order to damage components of the ROM memory including the barrier compound itself avoid the cumulative heat developed by all contacts together when the computer is running.

A typical example of a write-once ROM memory, in which a barrier ground is an electrical insulator initially on the first interconnection and then assumes an electrically conductive state by activation is described in US Pat. No. 3,576,549. For the production a complete regular matrix is required

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a semiconductor device in the form of a semiconducting substrate with at least one region of one conductivity type, e.g. an area with η conductivity which forms part of the support. On the surface of the carrier is a thin insulating layer such as silicon dioxide, aluminum oxide or silicon nitride, and on the thin insulating layer is at least one conductor over the area with the one conductivity type arranged. There are organs available to apply a voltage of sufficient magnitude and duration to the conductor, to break through the part of the insulating layer that is under the conductor and establish an electrical connection with the semiconductor device. To have electrical conductivity at reasonably well reproducible To obtain breakdown voltages, the thickness of the layer needs to be in the range from about 50 to 1000 A *, preferably from 100 to 600 A. Once such thin films "break through." they are difficult to restore if an error has occurred or a change to the schema is desired.

A complementary, write-once ROM memory matrix in which the barrier layer ground is electrical when it is first installed is conductive and then made electrically non-conductive is described in U.S. Patent 3,384,879. In series with the associated Diode-switched connections have a point of narrowed cross-section in order to avoid the destruction of the narrowed point, E.g. a bridge made of a low-melting metal, similar to a household fuse, is closed by a power surge enable so that the connection with the diode in question is interrupted. In practice, this metal bridge has to be very be narrow so that it has a sufficient electrical resistance and develops the Joule heat that leads to the destruction, e.g. by evaporation. Therefore, the resistance of this bridge determines the extent of the energy spread the memory matrix and limits the packing density of the diodes per unit volume.

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Barrier compounds, which are produced directly by vapor deposition of pure metal on a semiconducting support such as silicon may not be sufficient to provide sufficiently low contact resistance values, because this is possibly already prevented by a few monomolecular silicon dioxide layers which are can be located on parts of the semiconducting carrier in a memory matrix. The metals that are generally used for vapor deposition are those used in heating after vapor deposition at practical consideration Coming temperatures, such as 350 to 450 C, form alloys with the silicon substrate to produce long-lasting ohmic contacts to obtain the required low conductivity. An example of a vaporizable metal is aluminum.

The invention is based on the object of providing a ROM memory element that has a current-regulating Has barrier layer, which can be converted into a low-resistance state by electrical activation, a high one Allows packing density of components in a memory and at normal temperatures not spontaneously in a high-resistance State jumps back. Finally, the invention is based on the object of providing a component for a changeable ROM memory which makes it possible to repair faults or changes in the scheme of active semiconductor devices using simple electrical means at the temperatures that are usually used to make low-resistance contacts between conductors and semiconductor devices, is constant.

The invention relates to an electrical element for changeable ROM memory arrays consisting of a semiconductor device in direct contact with a compatible current regulating device electrical barrier, which by electrical treatment, as described below, to a low-

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0R-5526-A ^Ό 2 5 O 1 8 A 2

can activate ohmic state in which they have a relatively conducts weak read current, which is between the low-resistance state and a relatively high-resistance state Can switch back and forth and 10 to 90 percent by volume of a polymeric binder with a freezing temperature (T) of at least 60 ° C, preferably at least 100 ° C, and 10 to 90 volume percent of metal particles consists, which have an insulating coating and are dispersed in the binder. Preferably there is the barrier layer 75 to 15 percent by volume of binder and 25 to 85 percent by volume of metal particles to achieve a low To achieve resistance. The glass transition temperature T is published in accordance with the "Newer Methods of Polymer Characterization" by Bacon Ke, Verlag Interscience Publishers, New York, 1964, on page 393 et seq.

According to a preferred embodiment, binders are used and metal selected in such a way that a barrier layer is obtained which is able to withstand the temperatures that are used Make contacts between conductors and semiconductor devices, e.g., at temperatures in the range of 200 to 450 C, is heat resistant. A preferred method of electrical activation is the application of a direct current pulse of a short duration, usually a microsecond to a millisecond, to the barrier. You can do the electric Activation can also be brought about by briefly applying an alternating current voltage. When the barrier is in its low resistance State, it can be controlled with the help of a small pulse of about 0.1 to 10 mA, which is limited in terms of current intensity can be switched to the high-resistance state, whereby the pulse is regulated in such a way that the current strength at the end of the pulse drops very quickly to a new low value, usually zero. When the barrier is in its high resistance State, it can be changed by applying a voltage pulse, typically between about 10 and 300 V, can be switched to the low-resistance state, whereby the pulse is regulated in this way.

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It is valid that the current strength at the end of the pulse is proportional slowly drops to a low value.

To further explain the invention, reference is made to the drawings Referenced.

Fig. 1 is a sectional side elevation of an electrical element according to the invention showing the combination a semiconductor device having a current regulating electrical barrier layer. Fig. 2 is a partially sectioned view Executed side elevation of a row in an array of semiconductor devices, each device in spring loaded Is in contact with a continuous film of a mass regulating the electrical current. Fig. 3 is an im Cross-sectional side elevation showing a bonding contact with a p-conductivity region of a diode Barrier layer, a typical adjacent metal film that is on the adjacent n-type conductivity surface, a metal film on the opposite side of the barrier and a Tesla coil to activate the barrier in a low-resistance state ..

The electrical element shown in FIG. 1 according to the invention consists of a combination of a semiconductor device 1 with one compatible therewith, in direct contact with its standing barrier layer regulating the electric current 2. The semiconductor device can be an active device, like a diode or transistor, or a passive device like a thin film capacitor or resistor, be. The production of such devices by conventional diffusion and / or vapor deposition processes is known. the The semiconductor device and the current regulating barrier layer are both miniature in size for making a compact Allow aggregate of many such elements in the form of a matrix. Preferably the semiconductor devices are using thin-film or thick-film semiconductor methods as micro-

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0R-5526-A * 25Q1842

miniature devices formed. Usually they exist Elements in a matrix of components that are all similar to one another.

The semiconductor devices used according to the invention which have a given conductivity type in a surface region can be produced by impurity activation of semiconductor host crystal lattices in which the conduction takes place through electrons or through holes. Semiconductor host crystals are known in the art; See "Handbook of Chemistry and Physics ¹¹ , edited by the Chemical Rubber Company. Germanium and silicon are examples of preferred host crystals. Rules for the selection of the impurities that act as dopants. and the crystal n-conductivity (electron conduction) or p- Providing conductivity (hole conduction) are also known and are described, for example, in US Pat. No. 3,576,549.

The current-regulating barrier layers used according to the invention consist of a binder and metallic particles dispersed in it Filler particles. The polymeric binder has a glass transition temperature of at least 60 ° C., preferably at least 100 ° C, it should with the metallic filler particles do not react, and it has to withstand the thermal stresses involved in producing the system of which it is one Part forms, e.g. in the production of low-resistance contacts between conductors and semiconductor devices, for action come. According to one method of making ohmic contacts, heat is applied to an alloy between a metal, generally one deposited by vacuum evaporation Metal, and the semiconductor material in question. Typical bonds of this type are alloy bonds between metallic aluminum and a semiconductor made of silicon or between metallic gold and a semiconductor from germanium. Since the one to alloy the conductor with the. Semiconductor surface performed heating process the di-

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electrical ground of the current-regulating barrier layer is located on at least part of the semiconductor surface, and since the temperatures required for alloying are normally in the range of 200 to 450 ° C, the binder provided with fillers must be stable at these temperatures. For example, contacts between gold and germanium are heated to 300 ° C for about 5 to 30 minutes during their production, and the even more common contacts between aluminum and silicon are heated to 450 ° C for similar periods of time during their production. The ability of the filled binder to withstand the high temperature at which contact with the barrier layer is made without decomposing and becoming unusable can be determined by a simple experiment by taking the mass 2 hours into the prospect for alloy formation temperature taken heated and weight loss determined; Dielectric masses consisting of binders and fillers, which suffer a weight loss of not more than 3%, preferably not more than 1 % , are suitable as barrier layer masses. If casting from solution in a solvent is used to deposit the barrier layer compound when making contact, the solvent should be driven off to constant weight by heating the compound to 100 ° C, if necessary under reduced pressure, before the compound is subjected to the suitability test the temperatures required for alloying are heated.

About the polymeric binders that can be used for the barrier compositions In addition to pure polymers, it also includes polymers that contain small amounts of solvents or other substances which lower their freezing temperature somewhat by acting as plasticizers. Usually have such additives hardly any influence on the heat resistance of the polymers, since they usually have low boiling points and easily evaporate. In the manufacture of microcircuits, however, such additives should be avoided by volatilization from the poly-

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merisates are removed before metallic conductors by vacuum evaporation should be applied to avoid degassing problems and contamination of the pump oil. Under a Pure polymer is to be understood as an organic polymer that does not require any additional reactants transition to its stiff end state (high T) (e.g.

no crosslinking agents such as polyamines, which are used to cure epoxy resins, are required). According to the invention Usable rigid, pure polymers include essentially linear thermoplastic polymers and polymers, like aromatic polyimides, which, although theoretically linear, appear to be due to intermolecular Reactions between the functional groups of the polymer have a certain degree of crosslinking between the polymer chains exhibit (which results from their high degree of insolubility). Despite the possibility of crosslinking between polymer chains enables the use of such polymers "one-part" formulations for the production of the electrically activatable barrier layers, since additional crosslinking agents are not required. The polymers which can be used according to the invention Binders therefore enable the barrier layers to be produced quickly and easily.

The value of the elements according to the invention is very different from that Freezing temperature (T) of the polymer used depends. The higher the glass transition temperature, the higher the resistance the low-resistance state of the barrier layer. If the T is too low, the barrier will spontaneously go off

the low-resistance to the high-resistance state. In general, polymers have a glass transition temperature of at least 60 ° C required, and those with a freezing temperature equal to or greater than 100 ° C for elements preferred, which can be exposed to the action of higher temperatures.

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Representative polymeric binders with freezing temperatures of at least 60 ° C are organic polymers, such as the well-known polybenzimidazoles, aromatic polyimides, poly- (amide-imides), poly- (ester-imides), polysulfones, Polyamides, polycarbonates, polyacrylonitriles, polymethacrylnitri-Ie, Polymethacrylic acid methyl ester, polystyrenes, poly (α-methyl styrenes), Cellulose triacetates, polyvinyl alcohols and polyvinyl acetates. Representative representatives of these groups as well as theirs Freezing temperatures are listed in Table I. ·

Tabel

Organic polymers

Aromatic polyimide (DAPE-PMDA)

Aromatic poly (amide-imide) (MAB / PPD-PMDA)

Aromatic polysulfone polycarbonate

Aromatic polyamide (70 % IP / 30 % TP-MPD)

Polyacrylonitrile '

Polymethacrylonitrile "

Polymethacrylic acid methyl ester cellulose triacetate

Polystyrene

Polyvinyl alcohol 1

Polyindene

Polyvinyl carbazole

Polyvinyl chloride

Poly (vinyl chloride / vinyl acetate), 95: 5 Ethyl polymethacrylate, poly (vinyl chloride / vinyl acetate), 88:12

380 265 190 150 130

87, 120 105 105 100

85 84-85

82

63

DAPE = diaminodiphenyl ether PMDA = pyromellitic dianhydride MAB = m-aminobenzoic acid PPD = p-phenylenediamine

IP TP MPD = m-phenylenediamine.

Isophthalic acid chloride

Terephthalic acid chloride

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Aromatic polyimides with glass transition temperatures of at least 100 ° C. are a preferred class of compounds according to the invention Binder usable polymers. Such polyimides and their preparation are known per se, e.g. from the USA patents 3,179,630, 3,179,631, 3,179,632, 3,179,633, 3,179,634, and 3,287,311. Suitable polyimides have the general formula

- R ¹

in which η means such a large whole number that the polymer has the mechanical properties required for use as a binder, R means a tetravalent radical derived from an aromatic tetracarboxylic dianhydride, the aromatic moiety having at least one ring with 6 carbon atoms and benzene-like unsaturated ones Bonds, while R ^{f means} a divalent radical derived from a diamine. The aromatic tetracarboxylic dianhydrides which are suitable for the preparation of polyimides which can be used according to the invention include those in which "each of the four carbonyl groups of the dianhydride is bonded to a different carbon atom of a benzene ring, the carbon atoms of each pair of carbonyl groups directly to adjacent carbon atoms of a benzene ring Examples of dianhydrides which are suitable for the production of polyimides which can be used as binders are pyromellitic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, diphenyl-3,3 ¹ , 4,4'-tetracarboxylic dianhydride, naphthalene-1 , 2,5,6-tetracarboxylic dianhydride, diphenyl-2,2 ', 3,3'-tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride and benzophenone-3,3 '»4,4'-tetracarboxylic acid dianhydride.

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Organic diamines suitable for the production of polyimides which can be used according to the invention are those of the general formula HpN-R ¹ -NHp »* ⁿ ^ where the divalent radical R 'can be an aromatic, aliphatic, cycloaliphatic, aromatic-aliphatic, heterocyclic radical or an organic bridging radical which the bridging atom can be carbon, oxygen, nitrogen, sulfur, silicon or phosphorus. The radical R ¹ can be substituted or unsubstituted in a known manner. Preferred radicals R ¹ are those which contain at least 6 carbon atoms and are characterized by benzene-like unsaturated bonds, for example p-phenylene, m-phenylene, biphenylene, naphthylene and the remainder of the general formula

in which R "is an alkylene or alkylidene radical with 1 to 3 carbon atoms, denotes an oxygen atom, a sulfur atom or the radical SOp.

The diamines described above can also be used to produce polyamides which can be used as binders according to the invention. The diamines which are preferred for the production of the polyamides and polyimides which can be used as binders according to the invention include m-phenylenediamine, p-phenylenediamine, 2,2-bis- (4-aminophenyl) propane, 4,4'- Diaminodiphenylmethane, benzidine, 4,4 ^t -diaminodiphenyl sulfide, 4,4 * -diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone and 4 "_# 4 ^r -diaminodiphenylether.

Some polyimides are not easy to process because their melting points are too high. In such polyimides must the metal particles required for the barrier layer compound are incorporated during manufacture. For example can the metal particles are added to the polyamic acid, which is a processable intermediate in the manufacture of the po-

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lyimids forms. As is known, polyamic acids dissolve in suitable ones Carrier solvents. In such methods, the metal particles can be immersed in a polyamic acid in a carrier solvent disperse, and the amounts of polyamic acid and metal particles intimately mixed therewith by the dispersion are to be measured that in the conversion of at least part of the polyamic acid to the polyimide and the Removing at least a portion of the carrier solvent forms the above-described composition of polyimide and metal particles. Such compositions of polyamic acid, carrier solvent and Metal particles have dielectric properties and before the conversion of the polyamic acid to the polyimide and the Removal of carrier solvent, deform as desired.

A particularly preferred polyimide with a glass transition temperature of 380 ° C. can be prepared from the corresponding polyamic acid as an intermediate in N-methyl-2-pyrrolidone (commercially available as " PYRE-ML" wire enamel RC-5057). The polyimide formed from such a polyamic acid and containing aluminum particles in dispersion can withstand a temperature of 450 ° C long enough to produce (by alloying) low-resistance contacts between conductors made of aluminum and semiconductor devices made of silicon in the same or adjacent elements of a variable ROM memory , and it
be set.

and a temperature of 220 C can be

Aromatic polyamides with the required glass transition temperature are described in US Pat. Nos. 3,006,899, 3,094,511, 3,232,910, 3,240,760 and 3,354,127. Such a polymer, which can be used according to the invention, can be expressed by the formula - £ - COCgH ^ CONHCgH ^ NH -4- _n , in which η is a large integer A polymer of this formula in which the -COCgH ^ CO units are isophthaloyl and / or terephthaloyle units and the NHCgH ^ NH are particularly preferred Units are m-phenylenediamine units.

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A particularly preferred aromatic polyamide is obtained by reacting equimolecular amounts of m-phenylenediamine and phthalic acid chloride, the latter being a mixture from about 70 mole percent isophthalic acid chloride and 30 mole percent Is terephthalic acid chloride. Such a polymer with a glass transition temperature of 130 ° C is stable at 300 ° C enough to form an alloy of gold and germanium and is useful in the form of a dispersed metal powder containing Solution for making electrical current regulating barriers for germanium devices.

The metal particles used in the mass consisting of binder and filler have insulating coatings, see above that no electric current can flow through the polymeric binder from one metal particle to the other. Although the Particles themselves have an electrically conductive interior (10 to 10 S.cm), a thin, dielectric surface is sufficient, to impart surface resistance to the particles even when they touch each other in the binder. As a result, by simply dispersing metal particles Do not create a low-resistance electrical conduction path in the polymeric binder. The dielectric Surface that makes the metal particles non-conductive can be achieved by coating the particle surface with an insulating chemical compound of the metal to be coated, such as an oxide, sulfide or nitride of the metal. Easily available metals that are coated with an oxide layer that electrically binds the aggregate of particles in the binder makes insulating, are aluminum, antimony, bismuth, cadmium, chromium, cobalt, indium, lead, magnesium, manganese, molybdenum, Niobium, tantalum, titanium and tungsten. A preferred metal is aluminum with a tarnish film of insulating aluminum oxide that easily forms in the atmosphere.

The metal for the metal particles of the barrier layer mass according to the invention should be chosen so that it

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lying semiconductor surface is compatible. The chosen metal can be a nondoping agent for the host semiconductor, e.g., silicon, of the contact-forming surface area of the semiconductor device. It can also be a dopant for the host semiconductor, as long as the conductivity type it normally gives is the same as that of the contact-forming surface area of the semiconductor device. In other words: The metal is chosen so that it does not dop the host semiconductor in a sense that is opposite to that in which it was already doped when the semiconductor device was formed. It is e.g. it is known that aluminum is a p-type dopant and antimony is an n-type dopant for silicon. Hence it is aluminous Barrier layer with a p-doped silicon surface and an antimony-containing barrier layer with an n-doped Silicon surface compatible.

A mixture of metals can also be used as long as it is compatible with the semiconductor device as described above is. Such a mixture can be in the form of particles of an alloy and / or in the form of a mixture of pure Metal particles are present.

The size of the metal particles can be in the range * of about 0.01 up to 250 u. The particle size range of about 0.05 to 20 yes is preferred. In general, the mean particle size is no more than 0.1 times the barrier layer thickness.

The metal particles are contained in the barrier layer composition according to the invention in an amount sufficient for electrical activation. Generally, the metal particle content is 10 to 90 volume percent, usually at least 25 volume percent, and preferably 25 to 85 volume percent in order to achieve low resistance upon activation. The remainder missing 100% consists essentially of the polymeric binder. The amount of metal particles should not be so

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be great, -that the mechanical strength of the binder seriously suffers or the surface of the barrier layer becomes too rough.

The normally insulating but electrically activatable barrier compound is in consideration of the stiffness of the binder a shape-retaining solid material. The crowd and the Barrier layers can be used by many known methods to homogeneously distribute metal particles in a polymeric binder to create a barrier layer of the desired thickness and shape. For example, you get one Coating on a semiconductor surface by applying the metal particles applied in dispersion containing solution of the binder in a suitable volatile solvent. the Dispersion can be applied to the semiconductor by painting, spraying, dipping or other conventional methods, including those belonging to the drying by evaporation, applied to * which consists of binder and dispersed metal particles Preserve barrier. If a high-melting polyimide is used as the binder, it may be more appropriate to this binder in the form of the polyamic acid obtained as an intermediate product in solution in a suitable solvent to process. Such. Polyamic acid solution can be used for the barrier formation methods described above can be used. The solvent for the polyamic acid should be both with the polyamic acid as well as with the polyimide, which then is made from it, strongly associate and volatilized. Suitable solvents are Ν, Ν-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone and tetramethylurea. After this When applied to the semiconductor, the polyamic acid can easily be converted into the polyimide on the spot by heating, a ring closure takes place with elimination of water; before conversion to polyimide becomes the carrier solvent aborted.

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If the polymeric binder is easily meltable, one can create a barrier layer of the dispersed metal particles. Apply containing polymer melt by casting or extrusion onto the semiconducting carrier. Otherwise, you can cast a film on a carrier, then from. peel off the carrier and press it against the semiconductor contact to produce a barrier layer. _; . .

The current-regulating barrier layer is usually a layer whose shape and dimensions depend on the intended use. If the layer is in contact with areas of a semiconductor device that have n-conductivity or p-conductivity, it can be 25.4 to 2540 μ for microassembly elements and 0.1 to 25.4 ti for microcircuit elements be fat. Their width is usually at least twice their thickness and their length along the semiconducting support can be considerably greater. The electrical resistance through the layer in the non-activated state is normally more than 10 ohms. The electrical resistance in the dielectric barrier layer compound in its non-activated state, for example in the form of a current-regulating barrier layer, is based on the dielectric nature of the polymeric binder and the insulating coating on the metal particles dispersed in the binder. However, it can be overcome by applying an electrical potential to the ground, which exceeds the threshold value sufficient for electrical activation. It can be assumed that with such an electrical activation, electrical high-voltage discharges destroy the insulating coatings on those metal particles which are located on the path on which the electrical discharges arrive from the barrier layer to the semiconductor device. During the first discharge, at least one electrically conductive path is evidently formed through the barrier layer. As a result, electrical activation is prevented by a sudden initial over-

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gear to the low-resistance state.

A preferred method of electrical activation is this brief application of a DC pulse, usually for a period of 1 microsecond to 1 millisecond, to the Element. The polarity of the pulse is irrelevant. If the thickness of the barrier layer is less than 25 W, it usually suffices a voltage of 5 to 15 V; For greater thicknesses, voltages of up to several hundred volts may be required be. The current intensity is preferably limited to approximately 100 mA; however, if sensitive parts are in the path of the current, a limitation to lower currents may be necessary be.

Furthermore, the short application is also for the electrical activation an alternating current voltage generally applicable. In this case, the effect of the tension should not be significant be shorter than 1/2 period. In other respects the procedure is the same as above for DC activation described.

When the junction is in its low resistance state, it can be switched to the high-resistance state by a small, current-limited pulse of around 0.1 to 10 mA the pulse is regulated in such a way that the current strength at the end of the pulse to a new low very quickly Value, usually zero, decreases. The lower part of the specified range is preferred for the pulse; however can occasionally currents of even 50 mA may be required. Under a current limited pulse is a brief current flow to understand that with the help of a resistor connected in series with the switching device below a certain Big is kept.

When the barrier layer is in its high resistance state, can it with the help of a voltage pulse of typical

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40

about 10 to 800 V switched to the low-resistance state , whereby this pulse is regulated in such a way that the current strength falls relatively slowly to a low value at the end of the pulse.

To bring about the transition to the high-resistance state, one can use various means of supplying switching-off currents or current pulses. An advantageous one The possibility is a regulated voltage source in combination with a limiting series resistor, both of which are one Represent a current source that is capable of an output power of approximately 50 mA for a period of 0.1 to 1 second to feed. It can be seen that in this short period of time the current flowing through the barrier layer is steady up to Zero decreases, suggesting that the metallically conductive material is in the electrically conductive path of the switching process subject. The transition can be brought about even more suddenly (rapid fading) by means of a capacitor charge, which provide a peak current or peak current pulse of 25 to 50 mA for a period of 1 millisecond represents, which suggests that the electrically conductive paths suddenly become due to the rapidly decreasing current pulse to be interrupted. For relatively thick barrier layers in micro-assemblies (mierοassemblies) and for thin barrier layers in microcircuits, roughly this is sufficient same cut-off current. A suitable value for the cut-off current can easily be passed through for a given junction Identify attempts.

The voltage that is used to switch from high-resistance to low-resistance State is less than the voltage required to activate the same junction. In other respects are the methods for activating and downshifting from the high impedance to the low impedance state essentially the same. However, the person skilled in the art understands that for very fast switching from high-impedance to

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the low-resistance state sometimes an alternating current voltage is impractical.

Another method of electrical activation or switching from the high resistance state is to use a AC discharge. A Tesla coil or vacuum tester (commercially available) is often suitable for this purpose; however, with such a device it is difficult to precisely localize the activation. Usually one is enough very brief exposure to the discharge of the vacuum tester, whereby the electrode of the vacuum tester with the barrier layer outside Contact is kept.

The Tesla coil is a special type of transformer that is used to convert very high voltages from weak direct current To maintain secondary stresses. The primary circuit of the transformer runs through an automatic breaker ', which opens at a high frequency of around 500 to 2000 Hz and is closed. When the circuit breaker opens and closes, it occurs in the secondary circuit Discharges of unequal strength. The current-regulating junction is switched into the secondary circuit. The low resistance The state of the barrier layer is preferably established by adding (1) an air gap in the secondary circuit intercalated, for example by placing the pole of the Tesla coil about 0.65 to 1.3 cm away from the barrier layer brings to favor the interrupter discharge and to make the discharge current weaker and more unidirectional, (2) leads the Tesla coil pole from side to side so that the discharges cover the entire surface of the Barrier layer and many breakdown paths are created, and (3) the barrier layer and those in contact with it Semiconductor device isolated from earth by having the element either on its own or as part of a matrix on an electrically insulating support surface, so that the voltage drop and the current flow in the blocking

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layer can be reduced. Usually, Tesla coil discharges are sufficient from about 1 to 5 seconds to reach the point of diminishing return and bring about a transition of the dielectric barrier layer ground to the low-resistance state. As soon as this state is reached, the resistance value remains essentially unchanged when a weak read current is used. ,

The electrical resistance of the barrier layer in its low-ohmic state, determined with the Simpson ohmmeter, model 269, ranges from less than 1 ohm to about 1000 ohms and is usually in the range of 5 to 50 ohms. This resistance will by using large pieces of metal, by activating with high voltage (in any way) or by shortens the current path through the barrier layer. Higher resistance values for the low-ohmic state occur when the proportion of metal is less than 25 percent by volume.

The resistance in the high-ohmic state (for a barrier layer that has never been treated with a Tesla coil) is typically more than 10 ohms. However, once the barrier has been treated with a Tesla coil, it is achieved the resistance in a subsequent high-ohmic supply

3 7 was only 10 to 10 ohms.

The relationship between the high-resistance and the low-resistance

2 condition is at least 10 for a given barrier layer, which is enough for a wide range of applications. (Solid-state digital circuits work well when changed by one Order of magnitude, although a larger change is desired, to have a margin of safety.) Switching between the high-resistance and the low-resistance state can be carried out at least 10 times and often more than 100 times. Both the high-resistance and the low-resistance state are stable for months and are caused by weak read currents unaffected.

- 22 -

60982S / 0835

The element according to the invention that consists of a combination a compatible current regulating junction with a semiconductor device is generally suitable for changeable Storage systems of high packing density, which are made up of many such elements in the form of a matrix attached to them Contact conductors and suitable writing and reading organs are put together. The ease with which the scheme of the active semiconductors in a matrix can be changed by simple electrical treatments, the correction is designed errors or changes to the storage system when practical use very easy. When producing the elements combined to form a matrix, the preferred Current-regulating polyimide-based barrier layer withstand the elevated temperatures normally used to create low-resistance contacts between metallic Manufacture conductors and semiconductor devices, e.g. a temperature of 450 C, which is used for the alloying of aluminum applied to silicon. Also with regard to the production of such elements, the creation of a barrier layer can be achieved by Coating with polymer can be easier than with vacuum vapor deposition.

In the following examples, unless otherwise specified, parts relate to amounts by weight.

example 1

A. To produce a barrier layer for a microassembly, the following procedure is used: 2 parts of a commercially available atomized aluminum powder with spherical particles (with an average particle size of 20 μ) are stirred into a 15% by weight solution of 1 part of a solid polyamide dispersed in N, N-dimethylacetamide. The polyamide is a high molecular weight polycondensation product of equimolecular amounts of m-phenylenediamine and a mixture of 70 parts of isophthalic acid chloride

. - 23 60982b / 0835

and 30 parts of terephthalic acid chloride. The polyamide has a glass transition temperature of 130 ° C and a specific weight of 1.32. The mixture is poured onto a plate coated with a polytetrafluoroethylene film which has been preheated to 50 ° C. and then heated to 150 ° C. to cause the solvent to evaporate and to produce a film. The film is pressed with the aid of a plated with polytetrafluoroethylene and heated to 150 ⁰ C iron. The purpose of grouting is to create a smoother surface; pressing only leads to a slight decrease in thickness. The final thickness is 0.6 mm.

B. A mechanical support frame is produced, which has a matrix of 7x7 silicon diodes 3 (see. Fig. 2) (commercially available) each of which has a spring loaded Everett & Charles contact 4. The one described above Film 5 is inserted into the carrier frame so that the spring-loaded contacts 4 press against it. (After a Another method can be to press the film into direct contact with the diode areas, the exposed semiconductor surfaces with the metal particles selected to render the film compatible with the barrier layer.) Conductor 6 to 12 are arranged in rows in such a way that they are in contact with the free diode connections. The ladder 13 (shown) to 19 (not shown) are arranged in columns with the free side of the film opposite that Film surface that is in contact with the spring-loaded contacts stands, touch. The arrangement explains a system for a ROM memory which is series-connected current regulating Comprising barrier layers and semiconductor devices, each combination forming an element of the memory. With correct Alignment of the spring-loaded contacts can be made each element of the matrix separately by means of an electrical 250 V discharge a 0.002 pF capacitor to a low resistance state activate and then switch from the low-resistance to the high-resistance state in the manner described above.

- 24 609825/0835 '

Example 2

A. 2 parts of black, surface-oxidized aluminum powder with particle sizes from 0.01 to 0.03 η are mixed with the aid of a mortar and pestle in 5 parts of a commercially available 16.5 percent solution of a polyamic acid (15.2 % converted polymer solids) in N. -Methy1-2-pyrrolidone dispersed. The solution is poured onto a smooth, clean surface and heated to 135 ° C for 0.5 hour and then to 300 ° C for 1 hour to complete the formation of the polyimide binder for the dispersed aluminum particles and the solvent and condensation the polyamic acid to drive off the resulting polyimide water. The cured film of the barrier compound is 0.5μ thick and

has an electrical resistance of at least 10 ohms measured through the film from its surface to the Lower surface of the conductive support.

B. The film is made from high resistance by the following treatment dielectric state switched to a low-resistance conductive state: A Tesla coil * which is capable of high-frequency Generating high voltage discharges is placed 1.3 cm above the film, and discharges are taken from the coil directed across the film surface while the element is on an insulating ceramic stand. To The coil is switched off for 2 to 3 seconds. The electric one. Resistance is measured again and is now 50 ohms.

C. The ability of the barrier described above to between the low-resistance and the high-resistance state and to let switch and this switchability via a Maintaining the time span is shown as follows: The barrier layer is attached with the help of contact conductors connected to a commercially available regulated power source that is set to pass through a limiting resistor supplies a current of about 25 mA. By oscillo-

- 25 6U982 & / 083 5.

Scopic observation of a flow proportional to the flow of current to the element Signal, it is determined that the current decreases steadily to zero in 100 milliseconds. In it will the electrical resistance of the element measured again and is now 2.5 megohms; this resistance is enough to to inactivate a semiconductor diode during normal operation of an electronic computing system. The barrier then becomes switched back to its low-resistance state again with the help of the Tesla coil described above. Switching back and forth is repeated three more times and the element is stored in the active state. After three months the element is examined, it turns out to have retained its low resistance; it can still be toggled back and forth using the method described above.

D. The above data and the known heat resistance of the polyimide used as a binder suggest that the Barrier compounds of this example are particularly useful in making barrier layers for semiconductor devices that are to be subjected to relatively high temperatures, as is the case with semiconductor devices on the basis of silicon is the case, which can be produced as follows: semiconductor diodes made of single-crystal Silicon can be made from a melt by conventional growth methods (using a crystal nucleus) produces a single-crystal, doped silicon rod, which then becomes microplates or carriers can be cut up. By then allowing it to diffuse in a p-type dopant, such as boron, into the surface results in a rectifier diode. Such a diode is shown in direct contact with a barrier layer according to the invention in FIG.

According to known methods, an SiO ₂ layer 20, which is somewhat less than 0.5 μm thick, is produced on most of the diode surface in such a way that over part of the area

- 26 609825/0335

21 with p-conductivity and part of the area 22 with η-conductivity at a distance of about 5 to 10 µ from that Area with p-conductivity openings remain.

The exposed part of the area with p-conductivity is covered with a 2 to 5 U thick layer 23 of the one described above Barrier compound coated. The diode is then heated to 135 ° C. for 1/2 hour and to 300 ° C. for 1 hour to remove the solvent drive off and convert the polyamic acid into the polyimide. The barrier layer consists of aluminum particles 24, distributed in the polyimide 25. The conductive aluminum layers 26 and 27 are again made using known methods applied to the barrier layer or the area with η conductivity. Then the aluminum conductor 27 is on the base

22 with n-conductivity by heating for 5 to 30 minutes alloyed to 450 ° C with the silicon. The junction semiconductor element is then placed according to the invention by treating with discharges of a Tesla coil 28, as described in part B, activated. The element can switch between the active, low-resistance state using the switching process described in Part C. and the inactive, high-resistance state can be switched back and forth.

Example 3

A barrier compound is made by adding 1.0 g of commercially available Aluminum powder with 2.5 g of the polyamic acid solution described in Example 2 and 3 ml of dimethylformamide mixes. A microscope slide (2.5 cm 7.5 cm) is transverse with a series of 5 pairs of rectangular Strips of aluminum foil that glue on their back has, glued. The pairs of strips are glued on so that they almost meet along the center line of the slide, and each strip extends to the edge of the slide. The pairs of stripes are numbered 1 to 5, and the separation gap at the point where each strip

- 27 60982b / 08 3 5

0R-5526-A H

pair does not meet at the moment, is denoted by d (the distance is given in mm). The strips are 3.175 mm wide. Each gap and part of the associated pair of strips is then covered with a 50 to 75 Ji thick layer of the barrier compound overdrawn. The glass plate prepared in this way is then dried for 1/2 hour at 135.degree. C. and 1 hour at 300.degree. On that the barrier layers are activated with a Tesla coil as described above, and the resistance of each barrier layer is determined with a Simpson Model 269 ohmmeter. These resistance values are given in ohms and labeled L-1. Each barrier layer is then switched to the high-resistance state by briefly applying 18-20 V. The resistance is then determined again and designated as H-1. The barrier layers with the Tesla coil are then switched back to the low-resistance state, whereupon they have the resistance L-2. In this way, the barriers are switched back and forth, with the Resistance values H-2, L-3, H-3, L-4, H-4, etc. to L-22, H-22 are obtained; see table II.

- 28 -

609825/0835

Table II g

VJl VJI

I. Pair
No. . d L-1 H-1 L-2 H-2 L-3 H-3 L-4 H-4 L-22 H-2 J \)
VO 1 ' 0.5 6.0 2OK 6.5 2OK • X · > 20K . * 2OK 5 15K I. 2 0.5 9.5 2OK 8.0 2OK * 2OK * 2OK 9 15K 3 0.5 7.0 2OK 5.0 2OK * 1.5K * 2OK 3 2OK 4th 0.64 9.0 2OK 5.5 2OK * 500 ■ X- 2OK 6.5 8K 60982 5
Pair
No. 0.38
L-5 5.0
H-5, 2OK
L-6 4.0
H-6 2OK *
H-7 1000
L-8 H-8 250K 3.0 25K cn
--- 1 12th ■ X · 30th > 20K 6th * 2 30K ** OD 2 12th * 11 2OK ;. 4th * 2 30K co
cn 3 7.5 ■ * 13.5 2OK 9 • X- 4th .20K • X * 4th 8th 10.5 2OK 6.5 * 3.5. 5K -X- * 5 12th * 8.5 2OK 7.5 • X- 8th 25K -X- *.

* Resistance not determined.

** Switching cycles L «9, H-9 to L-21, H-21 not specified.

> = greater than. ^ ₁

5K = 5000 etc. ■ O

Example 4

There are barrier compounds using (different amounts of weight) aluminum powder and 10.0 g of the in Example 3 "prepared polyamic acid solution. Also according to Example 3, microscope slides are glued, however, the gap widths are 3.175 mm. The gaps are to a depth of 0.15 to 0.25 mm with the Covered barrier layer and the glass plates according to Example 3 at 135 ° C and 300 ° C heat-treated. One every barrier (after measuring the resistance H-1 with a Simpson ohmmeter, Model 269) is then activated by applying 600 V via a resistance of 10 ohms and the resistance L-1 is measured. After briefly applying 20 V across a resistor, the resistance value H-2 is measured. Then 50V will be across a resistance of 10 ohms is applied and the resistance L-2 is determined. The last two treatments are repeated (Here the resistance values H-3 and L-3 are obtained). The results can be found in Table III.

- 30 609825/0835

O) O QU OD

Al, g ■ Vol.-96
Al T a b e 1 1 e CII L-2 H-3 L-3 O
►T) Pair
No. 0.508 15th 240 U 250 VJl
VJi
ro
cn
I. 1-1 ti 15th H-1 L-1 Resistance, ohm 1200 U 175 > 1-2 Il 15th U * 240 H-2 270 U 280 1-3 Il 15th U 150 U 400 U 450 1-4 0.718 20th U 200 U 200 U 190 2-1 It 20th U 380 U 500 U 500 2-2 Il 20th . U s 200 U 210 U 210 2-3 Il 20th U 400 U 600 U 680 2-4 1,239 30th y 200 U 150 U 160 C. 3-1 It 30th U 600 ■ U "325 U 140 m 3-2 U 30th U 140 U 100 U 90 3-3 Il 30th U 100 U 140 U 135 3-4 U 90 U U 125 U U

* U ■ infinite.

Example 5

Masses are made from equal amounts by weight of commercially available aluminum powder and various binders. Each mass is applied to a microscope slide in a layer thickness of about 20 to 50 μm, measured after drying. The films are dried at room temperature for 24 hours and then at 40-50 ° C. for 4 hours. The percentage by volume of metallic aluminum in the dried masses is about 25 to 40 %. Two dots of commercially available silver paint, which serve as electrodes, are applied to the surface at a distance of 1 cm from each other. The coatings are then activated by applying 400 V DC voltage across a resistor of 10,000 ohms; contact is made by touching the applied super dots. The inter-dot resistance is then determined using a Model 269 Simpson Ohmmeter at the intervals shown in Table IV.

- 32 - 60 982 5/083

Table IV

ο co co

influence * binder from T to 61 the stability of the barrier layer 2 months 4 months Time spans) S.
UI
V η Apiezon fat 82 Resistance (0hm according to the specified U U 6 months VJl
(V)
σ>
I. Apiezon wax T ⁰ C 87, 103 0 U U U Stearic acid «-121 100 U U U U Beeswax «-121 105 150K * U U U Paraffin wax <-121 5OK * ü U U. Polyethylene <-121 105 1OK * U U U Polyether resin -121 130 5K * U U U Plastic putty (Du Pont) -121 ^ 130 5-10K * U U U "Duco" putty -67, -85 60-200 ■ υ U U Polyvinyl butyral - 200 12th 11.9 U Polyvinyl chloride 17K 4.3 4.4 - Polyacrylonitrile 12th 9.5 9.3 - Polystyrene 4.3 3.0 3.0 mm Cellulose triacetate 9.5 14th 11.3 3.0 Polymethacrylic acid 3-10 methyl ester 14th 5 5 Polycarbonate 6.0 6.1 - Aromatic polyamide 5 10 10 - Epoxy resin 6.0 10 10 10 10-20 10 7-13

«» 'Much smaller than <= smaller than

* = · Resistance becomes infinitely ro after a few seconds

^ f ss about. · Cn

5K - 5000 etc. ο

U = infinite '' '' - *

■ ■ ■ ■ ■ *> ·

Example 6

The dependence of the resistance after electrical activation on the content of a commercially available polystyrene or various polyimide binders on commercially available aluminum powder are examined. The samples are produced by dispersing the aluminum powder by hand in (about 20 percent) solutions of the polymer in question and the solutions are used to coat 0.10 to 0.13 mm thick microscope slides (2.5 cm 7.5 cm) will. The polystyrene samples are allowed to air dry at 50 ° C for several days (as the polystyrene is in Toluene was dissolved). The polyimide samples are treated according to one of the following three rules, depending on their type:

A. "5057 polyimide": air dried overnight at 80 ° C, then 30 minutes at 135 ° C and 60 minutes at 300 ° C held. A 15> 1 percent solution of the polyamic acid is used in N-methyl-2-pyrrolidone.

B. "Polyimide 10301-91": Overnight in air at 80-90 ° C dried, then heat treated at 250 ° C for 30 minutes. A 22.3 percent solution of the polyamic acid in Cresol.

C. "Pyre ML-111": Air dried overnight at 50 ° C, then heat-treated at 250 ° C for 30 minutes. A 31.3 percent solution of the polyamic acid in acetone is used.

After the films have been dried and / or heat treated, strips of commercially available silver paint are placed on each plate Applied 2.54 cm apart and allowed to dry overnight. Then the resistance with a Simpson device "269 Series 2 VOM". The plates are activated with the help of a commercially available Tesla coil, whereupon the resistance is measured again «, The values are

- 34 609825/0 835

JS

in ohms / square area _s condition because the dried films are about 25 ρ thick.

The results can be found in Table V. They show that the barrier layer is always non-conductive before electrical activation.

tend (initial resistance greater than 10 ohms / square area). The results also show that between aluminum powder contents of 7 and 10 percent by volume there is a threshold value between non-conductive and conductive. Finally, it can be seen that between aluminum powder contents of
10 and 25 percent by volume gives an intermediate range in which the resistance after activation depends on the content of aluminum powder, in particular between 10 and 15 percent by volume. Above this intermediate range, the resistance after activation is independent of the aluminum powder content.

- 35 609825/083 5

0R-5526-A

Tabel

Influence of the Al powder content in various binders

Resistance (ohms / square area) before and after activation

with the Tesla coil

5057 polyimide later later Polyimide 10301-91 resistance later later > 10 ¹⁰ > 10 ¹⁰ Al before > 10 ¹⁰ > 10 ¹⁰ Vol-96 Resistance 3OK Il Vol-96 _{> 10} 10 3OK Il 6.5 Al before 1K ■ 1.4M 4.5 H 4K Il 9.4 > 1O ¹⁰ 60 8K 6.6 Il 1.5K Il 12.2 Il 35 1K 8.6 Il 325 50 14.7 It 22nd 300 12.2 It 45 20th 17.2 Il 20th 20th • 15.8 Il 10 15th 19.5 H 15th 10 19.0 Il 10 10 21.7 Il 15th 10 31.9 Il 10 10 23.7 91 10 10 41.3 Il 10 5 25.7 Il 10 48.4 Il 10 10 34.2 It 10 • 65.2 It . 10 40.9 H 5 10 46.4 Il 5 70 50.9 It 5 30th 54.8 Il 'K = M = millions 58.0 It resistance Polystyrene resistance Il Al before Al. before Pyre ML-111 > 10 ¹⁰ > 10 ¹⁰ Vol-96 η Vol% It 3.2 η 4.0 It 4.8 ti 5.9 It 6.3 It 7.7 It 9.1 Il 9.4 Il 11.8 It 11.0 It 14.3 Il 12.7 Il 25.0 Il 14.2 It 33.4 Il 15.7 It 40.0 23.7 Il 51.2 29.3 It 34.1 It 38.3 Il 42.0 Il > = greater than 45.3 62.4 Thousands

- 36 -

60 9 8 25/0835

0R-5526-A Jf

Example 7

Two barrier layers are examined for their stability in the low-resistance state. One barrier layer comes with a Polyimide with a freezing temperature T suitable according to the invention and the other with a commercially available craft putty (liquid cement "Ambroid") with a freezing temperature of 45 ° C as a binder. For both barriers a commercially available aluminum powder is used. Following the procedure of Example 3, samples are made in the shape of 3.175 mm wide strips on microscope slides (2.5 cm 7.5 cm) made, to the previously two electrodes made of aluminum foil, each 3.175 mm wide, at a distance of 6.35 mm from each other have been glued on.

10 The initial resistance is greater than 10 ohms. the Discs are placed on a hot plate and kept in air at 125 ° C overnight. Then the discs are removed and activated with a Tesla coil. The resistance is then measured, and the disks are put back on the Placed on the heating plate and exposed to the accelerated aging temperature of 125 C. Thereupon the resistance becomes (cold) 'measured from time to time with the Simpson device VOM (on the R χ 100 scale). The results can be found in Table VI.

The results in Table VI show that the "Ambroid" putty produced an infinitely large barrier layers after 24 to 36 hours of exposure to 125 ° C Resist the polyimide barrier layers even after 132 hours of exposure to a temperature of 125 ° C remain relatively constant. This confirms that binder with high T, like a polyimide, result in barriers that are "on" at elevated temperatures have a longer lifespan and are therefore superior to lower T binders.

- 37 609825/083 5

All barrier layers in the examples within the scope of the invention 3 through 7 are suitable for use in direct contact with a compatible semiconductor device, as in Example 2 is explained for the production of the electrical elements according to the invention,

- 38 609825/0835

I. Barrier Layer Stability - ) test T a b e 1 12 h Ie V3 36 h t ι the time 125 ° C O
PO Previous year ) 1 Polyimide 270 [ «_ 72 h -552 VO
I. 2 150 compared to 170 ¹¹ Ambroid "putty 200 (125 ⁰ C) cn
I. sample 3 · Dependency 230 230 180 132 h 1. Manufactured
made of 4 g aluminum ) Oh (0hm) .230 190 minium in ) 1 160 420 of resistance > 1O ¹⁰ 60 h 170 10 g polyamide
acid solution 2 140 400 24 hours U _ > 10 ¹⁰ 230 O
CO 3 230 290 Il 190 Il 00 2. Manufactured
made of 4 g aluminum 160 230 Il > 10 ¹⁰ cn minium in 380 230 ti OO 10 g "Ambroid" -
putty 350 > 10 ¹⁰ U co
cn "> = greater than. 300 430 Jl f > 1O ¹⁰ Il 330

0R-5526-A ff

Example 8

Easily available particles of the metals listed in Table VII which (by exposure to atmospheric conditions generated) oxide coatings are dispersed in equal volumes of two different insulating binders, namely once in the polyamide binder of Example 1 and the other time in a commercially available polystyrene binder (as a 20 percent solution in toluene). By casting and drying the films to a thickness of about 0.6 mm square barriers made of the binders containing metal particles with a side length of 2.54 cm manufactured. Each film is then subjected to high frequency high voltage discharges using a Tesla coil that lasts 5 seconds across the surface of the barrier in question

is transferred from the high-resistance state (at least 10 ohms through the layer) to the low-resistance state. Table VII gives the resistivity (in ohms / square area) determined between conductive electrodes attached to opposite edges of the square barriers. Such layers are suitable as electrically operated switches in combination with semiconductor devices using the methods described above be applied to the transition in the -high-resistance state and to accomplish the shift back to substantially the same low resistance as in the table VII is indicated.

- 40 -

609825/083 5

OR-5526-A Table VII .2 501842 Polystyrene
binder 44.2 Specific resistance of the barrier layer
(Ohms / square area) 18.2 metal polyamide
binder 3.7 antimony 37.2 2.4 bismuth 31.2 3.7 cadmium 13.2 1.4 chrome 4.0 13.2 cobalt 2.2 1.0 . Indium 2.0 1.3 lead 99.2 7.2 magnesium 1.0 8.2 molybdenum 1.2 52 ' niobium 10.2 1.7 Tantalum 9.2 titanium 38 tungsten 2.7

809825/0835

Claims (18)

Claims (1. ^ electrical element for changeable ROM memory matrices, ^ - 'characterized by a semiconductor device in direct contact with a compatible current regulating device electrical barrier made up of 10 to 90 percent by volume of a polymeric binder with a glass transition temperature of at least 60 ° C as well as the remaining 90 to volume percent consists of metal particles, which are an insulating Have coating and are dispersed in the binder. 2. Electrical element according to claim 1, characterized in that the semiconductor device is a diode. 3. Electrical element according to claim 1 or 2, characterized in that that the polymeric binder is a polyimide. '. 4. Electrical element according to claim 1 or 2, characterized in that that the polymeric binder is a polyamide. 5. Electrical element according to claim 1 or 2, characterized in that that the polymeric binder is polystyrene. 6. Electrical element according to claim 1 to 5, characterized in that that the polymeric binder has a glass transition temperature of at least 100 ° C. - 42 - 60 9 8 25/0835 0R-5526-A * 7. Electrical element according to claim 1 to 6, characterized in that the metal particles having the insulating coating have an average size of 0.01 to 250 μ ! point. 8. Electrical element according to claim 7, characterized in that the metal particles having the insulating coating have an average size of 0.05 to 20 η . 9. Electrical element according to claim 1 to 8, characterized in that that the metal particles having the insulating coating are aluminum particles. 10. Electrical element according to claim 1, characterized in that the barrier layer to 15 to 75 percent by volume Binder and the remaining 25 to 85 percent by volume consists of metal particles that form an insulating coating exhibit. 11. Electrical element according to claim 1, characterized in that it consists of a semiconductor device in direct Contact with a compatible current-regulating electrical barrier layer exists, which becomes a low-resistance Can activate state in which it conducts a relatively weak reading current, and between the low-resistance and the high-resistance state can be switched. 12. Electrical element according to claim 11, characterized in that that the polymeric binder is a polyimide with a glass transition temperature of at least 100 ° C, the insulating Metal particles having a coating are aluminum particles and the semiconducting carrier is a semiconductor is made of silicon. 13. Electrical element according to claim 11, characterized in that that the current regulating electrical barrier in - 43 -609825/0835 0R-5526-A Form of a layer is arranged, and that 'the high resistance State of the barrier layer has a resistance that is at least 10 times the low resistance . 14. Electrical element according to claim 13 »characterized in that that the polymeric binder has a glass transition temperature of at least TOO C and the metal particles AIu- • are minium particles with an insulating coating. 15. Electrical element according to claim 14, characterized in that that the current-regulating electrical barrier layer has a thickness of 0.1 to 25.4 µm and the aluminum particles have an average size no more than 0-1 times the thickness of the barrier layer. 16. Electrical element according to claim 11, characterized in that ' net that the barrier layer by applying a momentary DC or AC pulse can be activated. 17. Electrical element according to claim 11, characterized in that that the barrier layer is in the high-resistance state, in which it is due to the action of a current-limited Impulse from 0.1 to 10 mA from the low-resistance state has been switched. 18. Electrical element according to claim 11, characterized in that that the barrier layer is in the low-resistance state into which it is switched from the high-resistance state by applying a voltage pulse of 10 to 800 V has been.' - 44 - 609825/0835