SU1585834A1 - Memory unit - Google Patents

Abstract

The invention relates to computing and can be used in the means of recording and storing information, automation devices. The purpose of the invention is to increase speed, reduce the energy consumption of the memory element. The element contains a switching layer 3 of dysprosium fluoride deposited on the semiconductor substrate 1. When switched to a conducting state, dysprosium fluoride is decomposed into ions. Dysprosium ions form a conductive channel. Upon reverse switching, dysprosium fluoride is formed again. Because the ionization energy of dysprosium fluoride is small, then the switchings take place in short times and are initiated by small currents. 3 il.

Description

The invention relates to computing, in particular, to memory elements based on dielectric and semiconductor materials, which can be used in the means of recording and storing information in the form of constant numerical arrays, standard computer programs, microinstructions, microprograms, devices, telephone communications And automation, as switches, distributors, as well as for creating multifunctional logic devices.

The purpose of the invention is to increase the speed and decrease the energy consumption of the memory element.

Fig. 1 shows the structure of the memory element: Fig. 2 shows the current-voltage characteristics of the memory element in high resistance (curve AOW) and low resistance (curve COD) sog.to; in FIG. 3, kinetic dependencies.

method of changing the current through the element when it is switched by a single voltage pulse from the high-resistance to the low-resistance state and vice versa.

The memory element contains a semiconductor substrate 1, a conductive layer 2, a switching layer 3, a metal electrode 4.

The memory element has a layered structure obtained by vacuum deposition of dysprosium fluoride on a silicon substrate of n-type conductivity with a specific resistance of 0.1-100 ohm-cm. Layer 3 of dysprosium fluoride has a thickness of 0.1-0.8 μm and specific resistivity Ohm- cm. On the layer 3 of dysprosium fluoride by thermal evaporation in vacuum through a stencil, a metal electrode 4 is applied with an area lying in the range 0.3-3 mm. To the back of the semiconductor under 00 00 SP 00 CO liw

spoons 1 by thermal spraying of the metal, a continuous ohmic contact (layer 2) is created in vacuum.

The memory element can also be made on a silicon substrate with 1 p-type conductivity or another semiconductor.

The memory element works as follows.

In the initial state, the element is in a high resistivity state and its resistance for the specified film thicknesses lies within Ohms, and the current-voltage characteristic is represented by the AOW curve (figure 2. When applied between layer 2 and electrode 4 of a constant or pulsed electric voltage, the polarity of which corresponds to the depletion of the surface of the substrate 1 by the main charge carriers, and the value exceeds the threshold value of 5-70 V; a quick switch takes place in a time less than 0.5 µs (FIG. 3) to a conducting state with resistance 10-10 ohms. The volt-ampere characteristic of the element after switching to the conductive state is depicted by the COD curve in Fig. 2. This state is stable, remembered by the element and saved when the power is turned off.

By applying a voltage enriching the surface of the semiconductor substrate 1 with the main charge carriers, and passing a current of a larger htorog value, about 100 µA, through the cell, the element is switched back from the conductive to the original high-resistance state during 0.4 μs ( FIG. 3). The switching energy from one state to another does not exceed 10 J.

The operation of the proposed memory element is due to the fact that, when a switching voltage is applied to the element in layer 3 of dysprosium fluoride, current is tied up in a narrow area of about 1 μm, which leads to local heating of the material and an increase in its conductivity. The combined effect of the electric field and temperature causes the disruption of the ionic bonds of dysprosium fluoride and the formation of dysprosium ions, which drift in the electric field to the negative electrode and form a conductive metal channel in the dysprosium fluoride layer. As the dysprosium ions accumulate around the negative electrode, the thickness of the dielectric layer in this area decreases,

and the intensity of the electric field increases, which causes a further increase in current. The presence of positive feedback in the channel leads to an avalanche-like process of forming a conductive metal channel from dysprose in the dielectric switching layer 3 matrix and switching the element to a low-impedance state, which is stored and stored when the power is turned off.

When a conductive channel is formed and the resistance of the switching layer 3 decreases, the voltage is redistributed in the cell, i.e. a decrease in the voltage drop on the layer 3 and an increase in the voltage drop in the depleted spatial charge region of the semiconductor substrate 1 near the boundary with the layer 3. At the same time, the spatial charge region limits the flowing current and protects the element from the irreversible breakdown of the dysprosium fluoride layer 3.

Thus, switching the element from the high-resistance to the low-resistance state corresponds to a local phase transformation of the material of the active region, when a conductive channel-metal dysprosium is formed in the dielectric matrix of the layer 3, surrounded by a region with excess fluorine. This channel is stable and maintained when the power is turned off.

By passing a current of opposite polarity, the magnitude of which is greater than the threshold value, the conductive channel material is heated, which leads to the mutual diffusion of dysprosium and fluorine atoms and the chemical interaction between them to form dysprosium fluoride. In this case, the conductive channel region restores its dielectric properties and the element switches to the original high resistive state.

Claims (1)

Invention Formula A memory element containing a conductive layer, a semiconductor substrate disposed on the conductive layer, a switching layer disposed on the surface of the semiconductor substrate, a metal electrode disposed on the surface of the switching layer, characterized in that in order to increase speed and reduce energy consumption memory element, the switching layer is made of dysprosium fluoride. / VVVNAATVVVXAAAAAAAAAA / VV fpue.1 y, MKA t 80 ftU n -10 -8 -6 -4 -2 40 4r Q8 1.1 Phage.Z Compiled by S. Korolev Tehred M. Morgental / g 6 8 W 12 U.S  / ULIG Proofreader S. Shekmar