Summary of the invention
In order to address the above problem, the invention provides a kind of bipolar transistor of multi-emitter, said transistor comprises: collector electrode; Be formed at the base stage on the said collector electrode; Be formed at least two emitters on the said base stage, said emitter is spaced; Wherein, said base stage is the total base stage of all said emitters, and said collector electrode is the total collector electrode of all said emitters.
According to a further aspect in the invention, the invention allows for the resistance-variable storing device unit based on the bipolar transistor gating of above-mentioned multimitter pmultiple emitter transistor, said resistance-change memory unit comprises: collector electrode; Be formed at the base stage on the said collector electrode; Be formed at least two emitters on the said base stage, said emitter is separated by insulating barrier; Be formed at the resistance-variable storing device on each said emitter; Wherein, said base stage is the total base stage of all said emitters, and said collector electrode is the total collector electrode of all said emitters.
In addition; The present invention also provides the resistance-variable storing device array of the bipolar transistor gating that forms according to said memory cells; The resistance-variable storing device unit that comprises a plurality of above-mentioned bipolar transistor gatings; The resistance-variable storing device unit of wherein said bipolar transistor gating is arranged in parallel and has common collector electrode, and base stage and emitter between each said resistance-variable storing device unit are isolated by second insulating barrier.
In addition, the present invention also provides the manufacturing approach that forms above-mentioned resistance-variable storing device unit, and said method comprises: A, the Semiconductor substrate with first doping type is provided; B, on said Semiconductor substrate, form and have first heavily doped layer that second type is mixed; C, on said first heavily doped layer, form second heavily doped layer, and said second heavily doped layer is divided at least two emitters with insulating barrier, and on each said emitter, form resistance-variable storing device with first doping type; Wherein the Semiconductor substrate of first doping type is a collector electrode, and first heavily doped layer that second type is mixed is a base stage, and said base stage is the total base stage of all said emitters, and said collector electrode is the total collector electrode of all said emitters.
Bipolar transistor according to multi-emitter of the present invention; Because a plurality of emitter common bases and collector electrode; Thereby reduce the area of bipolar transistor; And adopt the resistance-variable storing device of the bipolar transistor gating of this multi-emitter, owing to reduced the area of gate transistor, and then improved the storage density of resistance-variable storing device.
Embodiment
Disclosing of hereinafter provides many various embodiment or example to be used for realizing different structure of the present invention.Of the present invention open in order to simplify, hereinafter the parts and the setting of specific examples are described.Certainly, they only are example, and purpose does not lie in restriction the present invention.In addition, the present invention can be in different examples repeat reference numerals and/or letter.This repetition is in order to simplify and purpose clearly, itself not indicate the relation between various embodiment that discuss of institute and/or the setting.In addition, various specific technology and the examples of material that the invention provides, but those of ordinary skills can recognize the property of can be applicable to of other technologies and/or the use of other materials.In addition; First characteristic of below describing second characteristic it " on " structure can comprise that first and second characteristics form the embodiment of direct contact; Can comprise that also additional features is formed on the embodiment between first and second characteristics, such first and second characteristics possibly not be direct contacts.
With reference to figure 2; Fig. 2 shows the structural representation according to the bipolar transistor of the multi-emitter of the embodiment of the invention; The bipolar transistor of said multi-emitter comprises: collector electrode 11, and said collector electrode comprises the doping of the first kind, the said first kind is doped to the N type or the P type mixes; Be formed at the base stage 12 on the said collector electrode 11, said base stage 12 has the doping of second type, opposite types doping each other that said second type is mixed and the first kind is mixed; Be formed at least two emitters 14 on the said base stage 12, said emitter 14 is spaced; Wherein, said base stage 12 is total base stages of all said emitters 14, and said collector electrode 11 is total collector electrodes of all said emitters 14, thereby has constituted the bipolar transistor structure that a plurality of emitters have a collector electrode and base stage.
Further, also comprise the base lead 18 that is formed on the said base stage 12, be formed at the emitter terminal 22 on the emitter 14, and be formed at the metal level 23 on said base lead 18 and the emitter terminal 22.
The bipolar transistor structure of said multi-emitter has higher integration, littler area, is applied in the resistance-variable storing device, can effectively reduce the area of gate transistor, thereby improves the storage density of resistance-variable storing device.With reference to Figure 13; Figure 13 shows the structural representation according to the resistance-variable storing device of the bipolar transistor gating of the embodiment of the invention; Said resistance-change memory unit comprises: collector electrode 11, and said collector electrode comprises the doping of the first kind, the said first kind is doped to the N type or the P type mixes; Be formed at the base stage 12 on the said collector electrode 11, said base stage 12 has the doping of second type, opposite types doping each other that said second type is mixed and the first kind is mixed; Be formed at least two emitters 14 on the said base stage 12, said emitter 14 is separated by insulating barrier 17; Be formed at the resistance-change memory unit 21 on each said emitter 14; Said resistance-change memory unit comprises that resistance becomes functional layer; Said resistance becomes functional layer and can be clipped between the top electrode and bottom electrode of resistance-change memory unit, also can be clipped between top electrode and the emitter, under the alive outside effect; But the inverse conversion between the high and low resistance state is realized in the resistance-change memory unit, can one or more resistance-change memories unit be set according to real needs on each said emitter; Wherein, said base stage 12 is total base stages of all said emitters 14, and said collector electrode 11 is total collector electrodes of all said emitters 14.
Alternatively; Comprise that also the base lead 18 that is formed on the said base stage 12, the repellel that is formed on the said resistance-change memory unit go between 22; And be formed at the metal level 23 on said base lead 18 and the emitter terminal 22; Metal level 23 on the said base lead 18 is the bit line of said memory cell, and the metal level 23 on the said emitter terminal 22 is the word line of said memory cell.
Alternatively, also comprise the lightly-doped layer 13 that is formed between base stage 12 and the emitter 14, said lightly-doped layer 14 has and base stage 12 identical doping types.
In addition; The invention allows for a kind of resistance-variable storing device array of bipolar transistor gating; The resistance-variable storing device unit that comprises many above-described bipolar transistor gatings; The resistance-variable storing device unit of wherein said bipolar transistor gating is arranged in parallel and has common collector electrode, and base stage and emitter between each said resistance-variable storing device unit are isolated by second insulating barrier.
Below introduced in detail multi-emitter bipolar transistor structure and by the structure of the resistance-variable storing device of this multi-emitter bipolar transistor gating; The bipolar transistor structure of said multi-emitter has higher integration, littler area; Be applied in the resistance-variable storing device, improve the storage density of resistance-variable storing device.Below will describe the manufacturing approach of the bipolar transistor and the resistance-variable storing device of multi-emitter in detail, the embodiment of this manufacturing approach is in order better to explain and to understand the present invention, rather than restriction the present invention.
At step S01, the Semiconductor substrate with first doping type is provided, with reference to figure 3.In the present embodiment, said substrate 11 is a silicon substrate, and in other embodiments, said substrate 11 can also comprise other compound semiconductors, like carborundum, GaAs, indium arsenide or indium phosphide etc.According to designing requirement (for example p type substrate or n type substrate), substrate 11 can comprise the doping configuration of first doping type, and in the present embodiment, it is the p type that said substrate has first doping type.
At step S02, on said Semiconductor substrate, form first heavily doped layer with the doping of second type.With reference to figure 3, can on the substrate 11 of first doping type, form first heavily doped layer 12 through ion implantation with the doping of second type, for example on p type substrate, form n
+First heavily doped layer 12.
At step S03, on said first heavily doped layer, form second heavily doped layer, and said second heavily doped layer is divided at least two emitters with insulating barrier, and on each said emitter, form resistance-variable storing device with first doping type.
In one embodiment; Specifically; At first can on first heavily doped layer 12, form second heavily doped layer 14 through ion implantation with first kind doping, as shown in Figure 4, and because the carrier moving between second heavily doped layer 14 (for example p type) and first heavily doped layer 12 (for example n type); Formed the shallow doped region 13 of n type, as shown in Figure 5.Then, deposition bottom electrode 15 on second heavily doped layer 14, and form mask layer 16, said mask layer 16 can be photoresist, and is as shown in Figure 6.Then, utilize the graphical said device of lithographic technique, and stop on the semiconductor layer 11 of first kind doping; Between piling up 25, form deep trench 26, shown in Fig. 7, Fig. 8 (AA of Fig. 7 is to view, BB to view still like Fig. 6); And utilize lithographic technique graphically to pile up 25 again, and stop on first heavily doped layer 12, second heavily doped layer 14 is separated into the part of a plurality of separations by shallow trench 17; Shown in Fig. 9, Figure 10 (BB of Fig. 9 is still as shown in Figure 8 to view to view, AA); Thereby formed the structure of the bipolar transistor of multi-emitter, the unit 30 of the bipolar transistor of each multi-emitter keeps apart through deep trench 26, forms a plurality of emitters by shallow trench 17 separated second heavily doped layers 14; Wherein the semiconductor layer 11 of first doping type is a collector electrode; First heavily doped layer 12 that second type is mixed is a base stage, and said base stage is the total base stage of all said emitters 14, and said collector electrode is the total collector electrode of all said emitters 14.Then fill the dielectric material and form isolation 17, and on the base stage of said first heavily doped layer 12, form base lead 18, shown in figure 11.Then, remove mask layer 16 and form opening 32, and utilize side wall technology in opening 32, to form medium side wall 19, shown in figure 12.Then; Form resistance change material layer 21 in the opening between side wall 19 inwalls, and on resistance change material layer 21, form top electrode 20, thereby formed the resistance variation memory structure that comprises bottom electrode 15, resistance change material layer 21, medium side wall 19, top electrode 20; Shown in Figure 13, Figure 14 (vertical view); Be merely example here, resistance-variable storing device can also be other structure, for example only comprises that resistance becomes the structure of material and top electrode.
Then, can further accomplish following process as required, for example, on said resistance-variable storing device, form emitter terminal 22, and on said base lead and emitter terminal, form metal level 23, shown in figure 15.
More than the bipolar transistor of multi-emitter of the present invention and the resistance-variable storing device and the manufacturing approach of gating thereof have been carried out detailed description; Because a plurality of emitter common bases and the collector electrode of bipolar transistor; Thereby reduce the area of bipolar transistor; And adopt the resistance-variable storing device of the bipolar transistor gating of this multi-emitter, owing to reduced the area of gate transistor, and then improved the storage density of resistance-variable storing device.
Though specify about example embodiment and advantage thereof, be to be understood that under the situation of the protection range that does not break away from the qualification of spirit of the present invention and accompanying claims, can carry out various variations, replacement and modification to these embodiment.For other examples, when those of ordinary skill in the art should understand easily in keeping protection range of the present invention, the order of processing step can change.
In addition, range of application of the present invention is not limited to technology, mechanism, manufacturing, material composition, means, method and the step of the specific embodiment of describing in the specification.From disclosure of the present invention; To easily understand as those of ordinary skill in the art; For the technology, mechanism, manufacturing, material composition, means, method or the step that have existed or be about to later on develop at present; Wherein they are carried out the corresponding embodiment cardinal principle identical functions of describing with the present invention or obtain identical substantially result, can use them according to the present invention.Therefore, accompanying claims of the present invention is intended to these technology, mechanism, manufacturing, material composition, means, method or step are included in its protection range.