Description of drawings
Fig. 1 is the generalized section according to a kind of conductive bridging random access memory element of embodiments of the invention.
Fig. 2 is the generalized section according to the another kind of conductive bridging random access memory element of embodiments of the invention.
Fig. 3 is a kind of vertical view of example of the metal level of Fig. 2.
Fig. 4 is the vertical view of another kind of example of the metal level of Fig. 2.
Fig. 5 is the part enlarged drawing of Fig. 1 or Fig. 2.
Fig. 6 A to Fig. 6 F is the manufacturing process generalized section according to a kind of conductive bridging random access memory element of another embodiment of the present invention.
Description of reference numerals
100: conductive bridging random access memory element 102,600: the first electrode layers
110,602: dielectric layer 104,612: solid-state electrolyte layer
106,614: the second electrode lay 108,108a, 108b, 500,608: metal level
112: groove 114: inner surface
400: most advanced and sophisticated 604: the first grooves
606: 610: the second grooves in surface
Embodiment
Fig. 1 is the generalized section according to a kind of conductive bridging random access memory (CBRAM) element of embodiments of the invention.
Please refer to Fig. 1, the conductive bridging random access memory element 100 of present embodiment comprises first electrode layer 102, dielectric layer 110, solid-state electrolyte layer 104, the second electrode lay 106 and metal level 108, wherein the material of first electrode layer 102 is for example inert metal, as platinum (Pt), tungsten (W), titanium nitride (TiN) or nickel.Above-mentioned solid-state electrolyte layer 104 is to be positioned on first electrode layer 102, and the material of described solid-state electrolyte layer 104 comprises chalcogen compound (Chalcogenide), as germanium selenium compound (Ge-Se) or germanium sulphur compound (Ge-S); Or silver sulfide (Ag
2S), copper sulfide (Cu
2S), tantalum oxide (Ta
2O
5), tungsten oxide (W
2O
3) or silica (SiO
2).And the second electrode lay 106 is to be arranged on the solid electrolyte 104, and wherein the material of the second electrode lay 106 comprises silver (Ag) or copper (Cu).As for metal level 108 can be a kind of single-side structural, and it is other to be positioned at solid-state electrolyte layer 104, and wherein the material of metal level 108 is conductive metallic composite or metal material.Moreover the metal level 108 and first electrode layer 102 are electrical connected in Fig. 1.110 of dielectric layers are arranged between solid electrolyte 104 and the metal level 108, wherein the material of dielectric layer 110 silica (SiO for example
2), silicon nitride (SiN) or polymethyl methacrylate (Polymethylmethacrylate, PMMA).
In Fig. 1, dielectric layer 110 can have groove 112, and makes solid-state electrolyte layer 104 be positioned at groove 112.
The conductive bridging random access memory element 100 of Fig. 1 is in wiping (erase) process, owing to apply positive voltage at first electrode layer 102, connected metal level 108 can produce positive electric field, repel the metal ion that is scattered in the solid-state electrolyte layer 104, make that interconnective filament (Filament) is easily interrupted, promote element and change the efficient of paramount configuration by hanging down configuration, expection can improve the endurance (Endurance) of element and reduce switching time (Switching time).In addition, metal level 108 is also by external circuit, so that produce positive electric field in the erase process of conductive bridging random access memory element 100.
Fig. 2 is the generalized section according to the another kind of conductive bridging random access memory element of embodiments of the invention, wherein uses with Fig. 1 components identical symbol and represents same or analogous member.
Please refer to Fig. 2, conductive bridging random access memory element 200 wherein is that with the difference of Fig. 1 metal level 108 is bilateral structures, and solid-state electrolyte layer 104 then covers its inner surface with groove 112 profiles.Can be as for the second electrode lay 106 according to the form of solid-state electrolyte layer 104, the part position is in groove 112.
Fig. 3 and Fig. 4 are the vertical views of two kinds of examples of the metal level 108 of Fig. 2.Metal level 108a in Fig. 3 is the block structure of square type, and the metal level 108b among Fig. 4 is slightly crooked ear shape structure.
In addition, the metal level 108 of Fig. 1 or Fig. 2 also can have other distortion, as shown in Figure 5.Fig. 5 is the part enlarged drawing of Fig. 1 or Fig. 2, and metal level 108 wherein also comprises a tip (tip) 500, towards solid-state electrolyte layer 104 configurations, in order to add the highfield effect.
Fig. 6 A to Fig. 6 F is the manufacturing process generalized section according to a kind of conductive bridging random access memory element of another embodiment of the present invention.
Please refer to Fig. 6 A, on first electrode layer 600, form dielectric layer 602 earlier.The material of aforementioned first electrode layer 600 is for example inert metal, as platinum (Pt), tungsten (W), titanium nitride (TiN) or nickel.The material of aforementioned dielectric layer 602 is silica (SiO for example
2), silicon nitride (SiN) or polymethyl methacrylate (PMMA).
Subsequently, please refer to Fig. 6 B, carry out exposure imaging and etching, to form first groove 604 in dielectric layer 602, it exposes the surface 606 of first electrode layer 600.Form etching mode that above-mentioned groove 604 adopted for example dry-etching or Wet-type etching.And, still the invention is not restricted to this though show two first grooves 604 in the present embodiment, can also be single or plural structure.
Then, please refer to Fig. 6 C, in first groove 604, fill up the metal level 608 that can produce extra electric field, its step for example is prior to depositing metal layers 608 on the dielectric layer 602 and on the surface 606 of first electrode layer 600, utilizes chemico-mechanical polishing (CMP) mode to remove the metal level 608 on dielectric layer 602 surfaces again.Above-mentioned metal level 608 is conductive metallic composite or metal material.
Then, please refer to Fig. 6 D, carry out exposure imaging and etching, with formation second groove 610 in the dielectric layer 602 on first groove, 604 sides, and second groove 610 exposes the surface 606 of first electrode layer 600.In the present embodiment, the size of second groove 610 is greater than the size of first groove 604.In addition, the metal level 608 of present embodiment is a bilateral structure, so groove 610 can be formed between the bilateral structure.
In addition, the width w of the dielectric layer 602 between second groove 610 and first groove 604 is healed better little, can make the metal level 608 in first groove 604 produce significant electric field effect.And form etching mode that above-mentioned second groove 610 adopted for example dry-etching or Wet-type etching.
Come again, please refer to Fig. 6 E, on the dielectric layer 602, conformally deposit solid-state electrolyte layer 612 on the surface 606 of the inwall of second groove 610 and first electrode layer 600, its material such as chalcogen compound (Chalcogenide) are as germanium selenium compound (Ge-Se) or germanium sulphur compound (Ge-S); Or silver sulfide (Ag
2S), copper sulfide (Cu
2S), tantalum oxide (Ta
2O
5), tungsten oxide (W
2O
3) or silica (SiO
2) etc.Afterwards, deposition the second electrode lay 614 on solid-state electrolyte layer 612, its material is silver (Ag) or copper (Cu) etc. for example.
Then, please refer to Fig. 6 F, can remove second groove 610 solid-state electrolyte layer 612 and the second electrode lay 614 in addition, but, still can on the dielectric layer 602 beyond second groove 610, leave partly solid-state electrolyte layer 612 and the second electrode lay 614 as long as solid-state electrolyte layer 612 can not contact with metal level 608.And remove mode such as the dry-etching or the Wet-type etching of above-mentioned solid-state electrolyte layer 612 and the second electrode lay 614.
In sum, the present invention adds the metal level that affiliation produces extra electric field in original conductive bridging random access memory element, so when can be in erase process first electrode layer being applied positive voltage, make the metal level that is connected with first electrode layer produce positive electric field, repel the metal ion that is scattered in the solid-state electrolyte layer, to quicken to interrupt interconnective filament (Filament), promote element and change the efficient of paramount configuration, and then improve the endurance of element and reduce switching time by low configuration.
Though the present invention discloses as above with embodiment; right its is not in order to limit the present invention; those of ordinary skill in the technical field under any; without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is when looking being as the criterion that accompanying Claim defines.