CN101420013A

CN101420013A - Resistor conversion memory cell

Info

Publication number: CN101420013A
Application number: CNA200810203356XA
Authority: CN
Inventors: 张挺; 宋志棠; 刘波; 封松林; 陈邦明
Original assignee: Shanghai Institute of Microsystem and Information Technology of CAS
Current assignee: Shanghai Institute of Microsystem and Information Technology of CAS
Priority date: 2008-11-25
Filing date: 2008-11-25
Publication date: 2009-04-29

Abstract

The invention relates to a resistance conversion memory cell, which includes two metal electrodes and metal between electrode couples. An electrical signal is adopted to operate the memory cell. Reversible conversion between a high resistance and a low resistance can be realized for a component unit under the operation of the electrical signal so as to realize the function of data storage. Or a transition layer can be included between the electrodes and a metal layer. Appropriate pre-treatment is carried out to cause an interface between the electrodes (or the transition layer) and the metal layer to diffuse. The mutual diffusing effect between the electrode (or the transition layer) and the metal layer changes the components of a material near the interface. A particular component can realize the reversible resistance conversion under the effect of the electrical signal so as to realize the storage of data. The memory has the advantages of high speed, low power consumption and good ability of data holding and is an ideal memory.

Description

A kind of resistor conversion memory cell

Technical field

The present invention relates to the association area of semiconductor memory, specifically a kind of resistor conversion memory cell.

Background technology

Nonvolatile semiconductor memory has occupied consequence in information technology, its sales volume increases year by year, and it is applied in the consumer electronics ubiquitous especially, has vast market.At present, the most frequently used nonvolatile semiconductor memory is a flash memory, and the novel memory of other principles also continues to bring out, along with flash memory runs into technical bottleneck below the 32nm technology node, the novel semi-conductor memory will be in the near future part or significantly replace flash memory.For example, phase transition storage, ferroelectric memory, RRAM (resistor random-access storage) etc., wherein, phase transition storage more is considered to the most promising candidate of nonvolatile storage of future generation, has potential huge market value.

The principle of phase transition storage is based on the transformation of the resistance that the phase-change material phase transformation causes, the principle of RRAM then is based on the electric resistance changing of metal oxide under signal of telecommunication effect, although the principle of above-mentioned two kinds of memories all is based on the significantly transformation of the resistance of various materials, but also in metal, do not find at present, the significantly transformation of resistance.

Summary of the invention

The purpose of this invention is to provide the resistor conversion memory cell that a kind of storage medium is a metal, made memory obtain bigger high resistance and low resistance difference and data holding ability preferably.

For achieving the above object, the present invention has adopted following technical scheme:

The invention discloses a kind of resistor conversion memory cell, the storage medium in the memory cell is a metal, and metal is in the middle of the pair of electrodes, and the size and dimension of electrode can be identical, also can be different.During storage operation, by the operation of the signal of telecommunication, make memory cell between high resistance and low resistance, realize reversible resistance conversion, thereby realize the memory function of data.Thereby utilize the different resistance states of device to realize the storage of data, in storage, can be the twin-stage storage, also can be multistage storage.Storage medium in the above-mentioned resistor conversion memory cell is a metal, simultaneously, also should comprise an amount of doping that above-mentioned metal is carried out, the atomic percent of foreign atom is less than 10, and the dopant material kind can be to be one or more the combination in nitrogen, oxygen, titanium, tungsten, silicon, germanium, tantalum, aluminium, silver, gold, tin, nickel, indium, oxide, the nitride.

Perhaps, also can comprise one deck transition zone between electrode and the metal level, through rational preliminary treatment, interface between electrode (perhaps transition zone) and the metal level is spread, mutual diffusion effect has changed the component of near interface material between electrode (perhaps transition zone) and the metal level, and specific component can be realized the reversible transition of resistance under action of electric signals, thereby realizes the storage of data.Described buffer layer material can be one or more the combination in titanium, tungsten, silicon, germanium, tantalum, aluminium, silver, gold, tin, nickel, indium, oxide, the nitride.

As preferred version: described storage medium is an antimony metal.

The invention has the advantages that: have bigger high resistance and low resistance difference and data holding ability preferably, and have fast speeds and lower power consumption.

Description of drawings

Figure 1A is a kind of memory plan structure schematic diagram of structure wherein, and Figure 1B schematic cross-section, two figure all are that non-equal proportion is drawn.

The operating process that Fig. 2 A arrives high resistant based on the low-resistance of Fig. 1 device cell, Fig. 2 B figure is the I-V curve of high resistance device cell.

The memory cross section structure figure of the another kind of structure of Fig. 3, non-equal proportion is drawn.

The operating process that Fig. 4 A arrives high resistant based on the low-resistance of above-mentioned device cell, B figure is the I-V curve of high resistance device cell.

The data holding ability test of the above-mentioned device of Fig. 5.

Fig. 6 A antimony metal mixes the resistance of the material that obtains with variation of temperature (heating up and temperature-fall period) through the tungsten of 2 percent atomic ratios, Fig. 6 B antimony metal through the titanium doped resistance of material component that obtains of one of percentage atomic ratio with the variation of temperature curve.

The enlarged diagram at Fig. 7 A electrode and metal level interface, Fig. 7 B through after the DIFFUSION TREATMENT, has formed skim at the interface, and non-equal proportion is drawn.

Embodiment

Below in conjunction with drawings and Examples the present invention is further described.

Embodiment 1:

A kind of resistor conversion memory cell spare based on the metal storage medium, the device vertical view of the wherein class formation shown in Figure 1A, the sectional view of part shown in the dotted line after amplifying is shown in Figure 1B among the figure.In this case, be the example explanation as storage medium with antimony metal.Among Fig. 1, storage metal material antimony 13 is 50 microns (i.e. vertical direction of figure) with the contact area length of

electrode

11, and 12 is the dielectric material silica, and 14 is silicon base.In Figure 1B, the gap length between two electrodes is 20 microns.With the resistance value of the device of said structure by signal of telecommunication programmed settings after low resistance, the employing pulse duration is that the potential pulse of 50ns is programmed to device cell, obtain the typical programming curve from the low-resistance to the high resistant shown in Fig. 2 A, as seen from the figure, device just can be set to device higher Resistance states through applying lower voltage; The device of high-impedance state is carried out the scanning of direct current V-I, and the V-I curve that obtains sees from figure shown in Fig. 2 B, and device only needs lower electric current and voltage just can realize transformation from the high-impedance state to the low resistance state.

Embodiment 2:

In another structure, also be example with the antimony metal, device sectional view as shown in Figure 3,15 is the silicon oxide insulation transition zone among the figure, 16 is tungsten electrode, 17 is the metallic antimony layer, 18 is the TiN top electrode.The diameter of the tungsten electrode that adopts among the figure is about 250nm, and the thickness of antimony metal is 150nm, and the thickness of TiN is 30nm.When the resistance value of the device of said structure is set to low resistance, the employing pulse duration is that the potential pulse of 50ns is programmed to device, obtain the typical curve shown in Fig. 4 A, as seen, device cell just can be set to device higher Resistance states through the operation that applies low voltage; The device of high-impedance state is carried out the scanning of direct current V-I, and curve sees from figure shown in Fig. 4 B, and device only needs lower electric current and voltage just can realize transformation from the high-impedance state to the low resistance state.For the data holding ability under the high temperature that characterizes this device, device is toasted under the high temperature of 160 degree, simultaneously device is carried out reading of resistance, be illustrated in figure 5 as the variation of the device resistance that obtains with stoving time, as seen, the high-impedance state of device still is in high-impedance state after the baking of long period, so, have data holding ability preferably, can be used as the candidate of nonvolatile memory.

Shown in Fig. 6 A and the 6B, be respectively metallic antimony is carried out obtaining the resistance of material component with the variation of temperature curve after minim metal doped, this shows, even in metallic antimony, mix a spot of metal material with high electrical conductivity, can both make the material after the doping have the ability of resistance conversion, possess the value of in resistor conversion memory cell, using.

Embodiment 3:

Adopt the structure of embodiment 1 or embodiment 2, again by DIFFUSION TREATMENT, form because of the thin layer that diffuses to form at the near interface of metal and electrode (perhaps transition zone), thin layer obviously is the mixture of each atom in metal material and electrode (perhaps transition zone) material.Be example with the structure that transition zone is arranged below.

As shown in Figure 7, have Ti transition zone 21 between metal Sb layer 19 and electrode W20, by spreading the thin layer that has just formed layer 22, thin layer is atom doped the forming of Ti that Sb is come self-diffusion.By result shown in Figure 6, through after the DIFFUSION TREATMENT, can have the material layer of resistance transfer capability in the formation of the interface of metal material and electrode (perhaps transition zone), thereby can be used as storage through the specific material after suitably spreading.Utilize the principle of Fig. 7, by DIFFUSION TREATMENT, the formation at the interface of transition zone in memory cell and metal level has the thin layer of resistance transfer capability, just can realize storage.

Claims

1, a kind of resistor conversion memory cell comprises pair of electrodes and is arranged at storage medium between the electrode, it is characterized in that: described storage medium is for having the metal of resistance transfer capability under signal of telecommunication effect.

2, by the described a kind of resistor conversion memory cell of claim 1, it is characterized in that: be provided with transition zone between described electrode and the metal storage medium.

3, by the described a kind of resistor conversion memory cell of claim 1, it is characterized in that: the interface between described electrode and metal storage medium forms alloy thin layer through DIFFUSION TREATMENT, and the alloy thin layer of formation has the resistance transfer capability under signal of telecommunication effect.

4, by the described a kind of resistor conversion memory cell of claim 2, it is characterized in that: the interface between described transition zone and metal storage medium forms thin layer through DIFFUSION TREATMENT, and the thin layer of formation has the resistance transfer capability under signal of telecommunication effect.

5, by each described a kind of resistor conversion memory cell in the claim 2 or 4, it is characterized in that: described buffer layer material is one or more the combination in titanium, tungsten, silicon, germanium, tantalum, aluminium, silver, gold, tin, nickel, indium, oxide, the nitride.

6, by each described a kind of resistor conversion memory cell in the claim 1-4, it is characterized in that: described metal storage medium contains foreign atom, the atomic percent of foreign atom is less than 10, and the dopant material kind is one or more the combination in nitrogen, oxygen, titanium, tungsten, silicon, germanium, tantalum, aluminium, silver, gold, tin, nickel, indium, oxide, the nitride.

7, by each described a kind of resistor conversion memory cell in the claim 1-4, it is characterized in that: described metal storage medium is an antimony.