TW498326B - Formation method of magneto-resistance RAM with magnetic tunnel junction - Google Patents

Abstract

The present invention discloses a novel formation method of magnetic tunnel junction for magneto-resistance RAM, which comprises: first providing a substrate; depositing a pinned layer on the substrate; next, forming an insulating tunnel barrier layer on top of the pinned layer; next, depositing a free layer on the insulating tunnel barrier layer, so that a large single magnetic tunnel junction covers on the whole surface of the first insulating layer on the conductive wire layer; then, performing a etching process to etch through the free layer until reaching the surface of the insulating tunnel barrier layer, so as to transfer the large single magnetic tunnel junction pattern to a small magnetic tunnel junction.

Description

498326 V. Description of the invention (1) 5-1 Field of the invention: The present invention relates to a method for manufacturing a magnetoresistive random access memory (111381161: 0-resistance memory random access memory; MRAM). How to form a magnetoresistive random access memory (MTJ) of a magnetic tunnel junction (MTJ). 5-2 BACKGROUND OF THE INVENTION: · As the accumulation of semiconductor devices continues to expand, the area of use of chips (chips) It must be consistent or even reduced to continue to reduce the unit cost of the circuit. In order to meet the future development trend of the high-tech industry, the only way is to continuously reduce the design rule of the circuit. Therefore, the space occupied by the components With the design rule of circuit (design rule) gradually shrinks. With the development of semiconductor technology, the size of integrated circuit components has been reduced to the range of deep sub-micron. When the semiconductor is continuously reduced to the range of deep sub-micron, It has some problems in the process scaling. In the very large scale integrated circuit T c Ί τ (Very Large Scale Integrated circuits; VLSI) has more than 400 ohms. Alas, there are many types of memory in the 7-member domain. In recent years, in the process of the integrated circuit circuit purple 4 lettuce process, a kind of non-volatile storage element has been developed. The magnetoresistance is taken as soon as possible >> A / A ^ Money access §

P. 4 498326; MRAM). It is a semi-oxidative memory. Persistence.苴 fe somatic cell line holds the memory of some types of stored somatic energy. V. Description of the invention (2) memory random memory (MRAM) is an integrated base memory of memory elements and has unlimited memory (DRAM) direction to store data, so it is a memory that becomes close to the strong magnetic region Cell. According to this, the random access memory embodies the proposed junction; MTJ) (MRAM) high speed. Generally speaking, the magnetic flux contains a barrier material made of a suitable material according to the electrical resistance of each layer of resistor elements: Inter-conduction 'depends on the corresponding ί

Connected to the magnetic channel, the electrical F access memory of the memory cell is based on complementary metal. The resistance to random reading and writing times of the magnetoresistance differs from that of the magnetic memory, so it can be kept non-volatile. The resistance of magnetic material, one of which is magnetized memory or magnetoresistive random access. The magnetoresistive random access I conductor and magnetic memory are non-volatile memory and dynamic random access. The magnetic field of the strong magnetic field is converted. Duan uses a magnetic state to change it to be called a magnetoresistance. It can often be called a magnetized magnetic channel junction (magnet t material theory gives magnetoresistance: n: t, low operating voltage and high density, etc. The magnetoresistance of the memory interface structure of the sub-memory is randomly stored: the possibility of being there. The multi-layer electricity composed of the magnetized material = the direction of the magnetic polarization of the memory element determines the current production = element, magnetic resistance. The magnetic channel interface remembers to change the multiple layers to separate the two strong magnetic layers, and the 'resistance of two or two can be produced by the spin-polarized channel of one electron', and the moment between the two strong magnetic layers Magnetic direction channel current δ substrate ~ Reluctance random access memory 丨 ... 丨 Induction current is small. Therefore, the use of a minimum of 498326 in the body (,) V. Description of the invention (3) size active element (transistor or Diode) as an isolation element connected to the magnetic channel interface Switch (M TJ spinva 1 ve) element to define the magnetoresistive random access memory cell. The memory cell area on this structure can be defined by the size of the active cell or the magnetic channel interface memory cell. The magnetic channel is connected The surface rotation open relationship uses the magnetization direction of the free layer for data storage. The resistance of the memory bit depends on the relative magnetization relationship and the parallel or non-parallel relationship between the free layer and the fixed layer. During the read mode When comparing the absolute value of the interface resistance of a magnetic channel with a reference memory cell, the ratio of the magnetoresistance in this structure must be consistent with the absolute value of the resistance of the memory cell. When it is compared with a reference memory cell If the resistance of a group of active components in the memory shows a difficult resistance change, an error signal will be issued. Figure A shows the MR AM of a conventional magnetoresistive memory cell (MR AM). ) Array, this array contains a group of electrical conductive lines 1 1 0 A, 1 1 0 B, 1 1 C as horizontal word lines on the horizontal plane, and another group as parallel bits on the other horizontal plane Lines 1 2 0 A, 1 2 〇 B, 1 2 0 C. Electrically conductive lines. Bit lines 1 1 0 A, 1 1 Ο B, 1 1 0 C and word lines 1 2 0 A, 1 2 Ο B The directions of 1, 2 0 C are at a 90-degree angle with each other, so that when viewed from top to bottom, the two sets of lines are staggered with each other. One of the memory cells shown in Figure A and Figure B is 1 3 0 It is located at the intersection point in the vertical space where each word line and bit line cross each other. The memory cell .130 is a vertical stacking structure, which includes a magnetic channel junction 1 4 0 As shown in the first figure B. The magnetic channel junction 1 40 has a fixed layer 150 with a fixed magnetization direction and a free layer 160 with a changeable magnetization direction. A resistance layer is included between the fixed layer and the free layer. 17〇

498326 V. Description of the invention (4) During the operation of the array, the vertical current will pass through the memory cell 1 3 0. The vertical current path through the memory cell 130 occupies only a small part of the surface area, and the surface area connecting the word lines, the magnetic channel junction 140, and the bit lines are all the same. However, this traditional structure will lead to some problems. As the size of the memory cell becomes smaller, the magnetic field lines of the memory cell become more complicated. In addition, during the process of forming the memory cell, edge defects (e d g e d e f e c t) are generated when the sandwich structure is etched, and the requirement of #etch ratio is also high. On the other hand, the edge of the fixed layer is also easy to form a large discrete field (s t r a y f i e 1 d). Furthermore, because the resistance signal of the traditional memory cell is weak, it is difficult to measure the magnetic field of the traditional memory cell. In view of the above reasons, we need a new method for forming memory cells of magnetoresistive random access memory (MRAM) in order to improve the yield and yield of subsequent processes. 5-3 Purpose and Summary of the Invention: In view of the above-mentioned background of the invention, the conventional method for manufacturing magnetoresistive random access memory (MRAM) has many disadvantages. The present invention provides a method that can be used to overcome the traditional process. problem.

^ 326 V. Description of the invention (5) The main purpose of the present invention is to provide a kind of random magnetic resistance (mRAM ... manufacturing method. The present invention can form a kind of new magnetic channel 2 structure to replace the traditional structure and obtain a Better magnetic resistance. Therefore, this method can be applied to the deep sub-micron technology of semiconductor devices. The method can avoid the fixed area when forming the edge structure of a fixed layer. On the other hand, it is easy to measure and provide a method to increase the manufacturing cost. Invention of the Invention Another object of the present invention is to provide a method for forming a magnetic channel junction (MTJ) of a random-resistance random (MRAM). A large-area fixed layer is arranged in the magnetic channel junction to prevent solid dispersion. Field (stray field) and can produce edge defects in the etched sandwich. In addition, the present invention can obtain an etch stop layer by forming a large layer to reduce the complexity of the process. F The memory cell in the present invention has a strong The resistance signal represents the magnetic field of the memory cell of the present invention. According to this, the present invention can reduce the reluctance random access memory with better reluctance reproducibility, and reduce the cost. Therefore, 'This is sufficient for economic benefits. The element ^ ^ = the purpose described above, the present invention discloses a new semiconductor-conductor; manufacturing method. First, a substrate is provided. A first is formed on the substrate, The formation layer 'is covered with a first insulating layer on the first wire layer. Then, the connecting elements are connected in the first insulating layer to connect the first wire layer. Then depos. (Magnetron sputter 111 〇n) uniformly forming a continuous layer for manufacturing magnetic channel junctions on the 498326 fifth, the description of the invention (6) an insulation layer and the surface of the connecting element. It is, in order, along the first insulation layer A pinned layer is deposited on the surface of the connecting element. An insulating tunnel barrier layer is formed on the upper end of the pinned layer. A free layer is then deposited on the insulating channel barrier layer. Therefore, a large single magnetic channel junction surface covers the entire surface of the first insulating layer on the wire layer. Subsequently, the free layer is etched through an etching process to the surface of the insulating channel barrier layer. In order to transfer this large single magnetic channel junction pattern into a small magnetic channel junction. Then, a second insulating layer is covered on the magnetic channel junction. After that, an advanced silicon super large integrated circuit is used. The process is to open a contact hole in the second insulating layer of the small magnetic channel junction. Finally, a second wire layer is formed on the structure to connect the free layer in the small magnetic channel junction. 5-4 Invention Detailed description of the invention: The direction of the present invention is a method of manufacturing a semiconductor device. In order to fully understand the present invention, detailed steps will be proposed in the following description. Obviously, the implementation of the present invention is not limited to Special details familiar to the artist of semiconductor components. On the other hand, well-known process steps are not described in detail to avoid unnecessary limitations of the present invention. The preferred embodiments of the present invention will be described in detail as follows. However, in addition to these detailed descriptions, the present invention can also be widely implemented in other embodiments, and the scope of the present invention is not limited, which is subject to the scope of subsequent patents. .

498326 V. Description of the invention (?) Referring to the second figure A, in one embodiment of the present invention, a semiconductor substrate 200 is first provided. On the semiconductor substrate 200, a first conductive layer 21 is formed, for example, a word line, and is covered with a first insulating layer 220. It-person 'forms a contact hole in the first insulating layer 220 to expose a part of the surface of the first wire layer 21. After that, a connecting element 230 is formed, such as a diode, in the contact hole of the first insulating layer 220 to connect the first wire layer 210. Then, a continuous layer for manufacturing the magnetic channel junction 240A is uniformly formed on the surfaces of the first insulating layer 2 2 0 and the connecting member 2 3 0 by a magnetron> magnetron SpUtter deposition method. Referring to FIG. 2B, in this embodiment, the sequence is to deposit a multilayer magnetized material (for example, Ni, Co, F) along the surfaces of the first insulating layer 220 and the connecting element 230. e alloy) pinned layer 250, wherein the polarization direction of the pinned layer 250 is uniform and fixed. An insulating tunnel barrier 1 ayer 2 60 is formed on the upper end of the fixed layer 2 50. The method of forming the insulating channel barrier 2 60 is to deposit and perform an aluminum material. An oxidation process is performed to form an aluminum oxide layer, such as A 1 2 0 3. Then, a free layer 2 70 having a multilayer magnetization material (such as Ni, Co, Fe alloy) is deposited on the insulating channel barrier layer 2 60, wherein the free layer 2 70 has Changing direction of polarization. Therefore, a large single magnetic channel junction surface 2 40 A covers the entire surface of the first insulating layer 2 2 0 on the first wire layer 2 10.

498326 V. Description of the invention (8)-Refer to Figure 1c. In this embodiment, a photoresist layer 2 75 is formed and defined on the free layer 2 70. Then, the photoresist layer 2 75 is used as an etch mask and a worm etch process # to pass through the free layer 2 7 0 until the surface of the insulating channel barrier layer 2 60 to facilitate the connection of this large single magnetic channel. The surface 24〇a ^ case is transferred into a small magnetic channel interface 2 4 0 B. Subsequently, a first / layer 280 is covered on the magnetic channel junction 240B. After that, a junction is formed; the Shu hole is in a second insulating layer 280 on a small magnetic channel junction 24B. Finally, a second wire layer 290, such as a one-bit wire, is formed on the above structure to connect the free layer 2 60 in the small magnetic channel junction 2 4 0 B, as shown in the second D diagram. As described above, in the embodiment of the present invention, a method for manufacturing a magnetoresistive random access memory (MRAM) is provided. The invention can form a new structure of the magnetic channel junction to replace the traditional structure and obtain a better reluctance of magnetoresistance. Therefore, this method can be applied to the technology of deep submicron semiconductor devices. In addition, the method can form a fixed layer with a large area in the interface of the magnetic channel to prevent a discrete field from being generated at the edges of the fixed layer & 忖 2 f 1 e 1 d) and to avoid sandwiches during the etching process The defects of the structure are shown in the second E diagram. On the other hand, since the memory cell of the present invention has a strong resistance signal, it is easy to measure the magnetic field of the memory cell of the present invention. In addition, the present invention can reduce the complexity of the process by forming a large-area fixed layer = an etch stop layer. According to this, the present invention can provide a magnetoresistive random access memory with better magnetoresistive reproducibility to increase the yield and yield of the manufacturing process, and can reduce the cost accordingly. In other words, the method of the invention can be economically beneficial.

Page 11 498326 V. Description of the invention (9) Of course, the present invention may be used in the process of forming a magnetic channel junction, or it may be used in the manufacture of any magnetoresistive random access memory device. Moreover, the present invention has not developed a method for manufacturing a magnetoresistive random access memory by using a large pinned layer to avoid edge defects and obtain a strong resistive signal. For deep sub-micron processes, this method is a better and feasible process for magnetoresistive random access memory. Obviously, according to the description in the above embodiments, the present invention may have many modifications and differences. Therefore, it needs to be understood within the scope of the appended claims. In addition to the above detailed description, the present invention can be widely implemented in other embodiments. The above are merely preferred embodiments of the present invention, and are not intended to limit the scope of patent application for the present invention; all other equivalent changes or modifications made without departing from the spirit of the present invention should be included in the following applications Within the scope of the patent.

498326 Brief description of the diagram. The first diagram A shows a structural sectional view of a conventional magnetoresistive random access memory with a conventional magnetic channel junction. The first diagram B shows a structural sectional view of a conventional magnetic channel junction. Figures A through D are cross-sectional views of a process for forming a magnetoresistive random access memory with magnetic channel junctions according to a preferred embodiment of the present invention; and Figure E shows a comparison with one of the present invention. Structural sectional view of the magnetic channel junction of the preferred embodiment. The main part of the symbol: 1 1 〇 A character line. 1 1 Ο B word line. 1 1 0 C character line. 1 20A bit line. 1 2 〇 B bit line. 1 2 0 C bit line. 130 Traditional magnetoresistive random access memory cells. 140 Traditional magnetic channel junction. 15 0 Fixed layer. 160-channel barrier layer. 17 0 Free layer.

Page 13 498326 Schematic illustration of 2 0 0 semiconductor substrate. 210 First wire layer. 2 2 0 First insulation layer. 2 3 0 Link components. 2 4 0 A large-area magnetic channel junction. 2 4 0 B Small-area magnetic channel interface 2 5 0 Fixed layer. 2 6 0 Insulated channel barrier.

Page 14

Claims (1)

498326 6. Scope of patent application 1. A method of forming a magnetic channel junction of a magnetoresistive random access memory, the method includes at least the following steps: providing a substrate; forming a first magnetized layer on the substrate Forming an insulating channel barrier layer on the first magnetization layer; forming a second magnetization layer on the insulating channel barrier layer; forming and defining a photoresist layer on the second magnetization layer; by the light The resist layer acts as an etching mask to etch the second magnetization layer until the insulating channel barrier layer; and removing the photoresist layer to form the magnetic channel interface. French side. The directional square-shaped chemical planes are extremely close to each other, and the Dao Dingtong solid magnetic one contains the lesser items to the first layer of the surrounding magnetic field Fan Yilidi. The special application is applied as described above and its legal formula is. The side of the product shape contains the τΉ layer that describes the steps from the enveloping road to the magnetic step. The layer is surrounded by the magnetic field. Fanyi Lidi's special application is as described above. 3. If the scope of patent application is the first The method for forming a magnetic channel junction according to the item, wherein the above-mentioned insulating channel barrier layer includes at least an oxide layer. 5. The method for forming a magnetic channel junction according to item 4 of the scope of the patent application, wherein the above oxide layer includes at least one oxide layer. 6. The method for forming a magnetic channel junction as described in item 1 of the scope of patent application, Page 15 498326 6. Scope of patent application Wherein, the above-mentioned method for forming the insulating channel barrier layer includes at least a deposition process. 7. The method for forming a magnetic channel junction as described in item 1 of the scope of patent application, wherein the method for forming the above-mentioned insulating channel barrier layer includes at least an oxidation process. 8. The method for forming a magnetic channel junction according to item 1 of the scope of the patent application, wherein the second magnetized layer includes at least one variable polarization direction. 9. The method for forming a magnetic channel junction according to item 1 of the scope of the patent application, wherein the step of forming the second magnetized layer includes at least one deposition process. 1 0. A method for forming a magnetic channel junction of a magnetoresistive random access memory, the method includes at least the following steps: providing a substrate; forming a fixed layer on the substrate; depositing and forming an aluminum Layer on the fixed layer; An aluminum oxide layer is formed by an oxidation process, so as to form an insulating channel barrier layer on the fixed layer; forming a free layer on the insulating channel barrier layer; forming and defining a photoresist layer on the On the free layer; engraving the free layer with the photoresist layer as an insect insect mask # until the insulating channel barrier layer; and Page 16 498326 6. Scope of patent application Remove the photoresist layer to form the magnetic channel junction. 11. The method for forming a magnetic channel junction according to item 10 of the scope of the patent application, wherein the fixed layer includes at least one magnetized material. 1 2. The method for forming a magnetic channel junction as described in item 10 of the scope of patent application, wherein the fixed layer includes at least a fixed polarization direction. 1 3. The method for forming a magnetic channel junction as described in item 10 of the scope of the patent application, wherein the step of forming the above-mentioned fixed layer includes at least one deposition process. 14. The method for forming a magnetic channel junction as described in item 10 of the scope of the patent application, wherein the above-mentioned free layer includes at least one magnetized material. 15. The method for forming a magnetic channel junction as described in item 10 of the scope of the patent application, wherein the above-mentioned free layer includes at least one variable polarization direction. 16. The method for forming a magnetic channel junction as described in item 10 of the scope of the patent application, wherein the step of forming the free layer described above includes at least one deposition process. 1 7. A method for forming a magnetoresistive random access memory with a magnetic channel interface, the method includes at least the following steps: providing a substrate; forming a first wire layer on the substrate, and -A first insulating layer 498326 VI. First line of patent application; go straight to the second guide to the first magnetic layer of the first layer of the first layer of the dew yuan. Expose the knot; magnetic ·, the exposure to connect to the upper ·, the two sides to the Connected to the first layer, the middle layer and the barrier layer, the middle layer and the middle layer of the magnetoresistance facet through layer, the hole. The edge of the hole is magnetically etched, the magnetic contact surface contact is absolutely contacted, the second act is said, the watch is connected, the edge is covered, and the cover is connected to the two points. The first part is taken at the moment. The first layer should be etched, overlaid, one should be stored in the other, and the one in the layer; one that is made in the machine, the hole, and the layer in the resistance layer to form a stop layer. Dow light is connected to the surface element magnetic flux by the edge contact line resistance layer by layer, the magnetic flux line is layered, the magnetic flux line is connected, the edge is the ambiguous resistance, the resistance is 2222. Light blocking No. 1st II II one by one and the one by one formation of the road is formed by the pass through the formation of the formation and the shape of the layer is shaped by the edge of the shape The layer is on the line; the cover is conductive; the track is magnetic 1 8. The method for forming a magnetoresistive random access memory as described in item 17 of the scope of patent application, wherein the first magnetic layer described above includes at least one fixed Direction of polarization. 19. The method for forming a magnetoresistive random access memory according to item 17 of the scope of the patent application, wherein the step of forming the first magnetization layer includes at least one Page 18 498326 6. Scope of patent application Deposition process. 20. The method for forming a magnetoresistive random access memory according to item 17 in the scope of the patent application, wherein the above-mentioned insulating channel barrier layer includes at least an oxide layer. 2 1. The method for forming a magnetoresistive random access memory as described in item 20 of the scope of patent application, wherein the above oxide layer includes at least one oxide layer. 2 2. The method for forming a magnetoresistive random access memory as described in item 17 of the scope of the patent application, wherein the method for forming an insulating channel barrier layer includes at least a deposition process. 2 3. The method for forming a magnetoresistive random access memory as described in item 17 of the scope of the patent application, wherein the method for forming an insulating channel barrier layer includes at least an oxidation process. 2 4. The method for forming a magnetoresistive random access memory according to item 17 of the scope of the patent application, wherein the second magnetization layer includes at least a variable polarization direction. 25. The method for forming a magnetoresistive random access memory as described in item 17 of the scope of the patent application, wherein the step of forming the second magnetization layer includes at least a deposition process. 498326 6. Application Patent Scope 2 6. —A method for forming a magnetoresistive random access memory with one magnetic channel interface, the method includes at least the following steps: providing a substrate; forming a word line layer on the Forming a first contact hole in the first insulating layer to expose a part of the surface of the word line layer on the substrate, and covering the word line layer with a first insulating layer; forming a connection A component in the first contact hole to connect the word line layer Forming a fixed layer on the first insulating layer and the connecting element; depositing and forming an aluminum layer on the fixed layer; forming an aluminum oxide layer by an oxidation process so as to form an insulating channel on the fixed layer A barrier layer; forming a free layer on the insulating channel barrier layer; forming and defining a photoresist layer on the free layer; using the photoresist layer as a # 刻 幕 幕 # to etch the free layer until the insulation Up to the barrier layer; Removing the photoresist layer to form the magnetic channel interface; forming a second insulating layer covering the magnetic channel interface; forming a second contact hole in the second insulating layer to expose the magnetic channel interface A part of the surface of the free layer; and forming a bit line layer in the second contact hole to connect the free layer and form the magnetoresistive random access memory. Page 20 498326 6. Scope of patent application 2 7. The method for forming a magnetic channel junction as described in item 26 of the scope of patent application, wherein the above-mentioned fixed layer includes at least one magnetized material. 28. The method for forming a magnetoresistive random access memory as described in item 26 of the scope of the patent application, wherein the fixed layer includes at least a fixed polarization direction. 29. The method for forming a magnetoresistive random access memory according to item 26 of the scope of the patent application, wherein the step of forming the fixed layer includes at least one deposition process. 30. The method for forming a magnetoresistive random access memory according to item 26 of the scope of the patent application, wherein the above free layer includes at least one magnetized material. 3 1. The method for forming a magnetoresistive random access memory as described in item 26 of the scope of the patent application, wherein the above free layer includes at least a variable polarization direction. 32. The method for forming a magnetoresistive random access memory according to item 26 of the scope of the patent application, wherein the step of forming the free layer described above includes at least one deposition process. Page 21