# US 10,374,006 B1 · Magnetic random access memory cell structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,006 B1 - Document ID: US10374006B1 - Status: Granted - Kind: B1 - Application number: 16/055,174 - Filed: 2018-08-06 - Granted: 2019-08-06 - Earliest claimed: 2018-07-19 - Assignees: United Microelectronics Corp. - Applicants: United Microelectronics Corp. - Inventors: Chung-Liang Chu; Yu-Ping Wang; Yu-Ruei Chen - Web page: https://patentgrep.com/patent/US10374006B1 ## CPC - H10B 61/22: {of the field-effect transistor [FET] type} - G11C 11/161: {details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell} - G11C 11/1655: {Bit-line or column circuits} - G11C 11/1657: {Word-line or row circuits} - G11C 11/1673: {Reading or sensing circuits or methods} - H10N 50/10: Magnetoresistive devices - H10B: ELECTRONIC MEMORY DEVICES - G11C: STATIC STORES (semiconductor memory devices H10B) - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract The present invention provides a magnetic random access memory (MRAM) structure, the MRAM structure includes a transistor including a gate, a source and a drain, and a magnetic tunnel junction (MTJ) device, the MTJ device includes at least one free layer, an insulating layer and a fixed layer, the insulating layer is disposed between the free layer and the fixed layer, and the free layer is located above the insulating layer. The free layer of the MTJ device is electrically connected to a bit line (BL). The fixed layer of the MTJ device is electrically connected to the source of the transistor, and the drain of the transistor is electrically connected to a sense line (SL). And a first conductive via, directly contacting the MTJ device, the material of the first conductive via comprises tungsten. ## Claims ### Claim 1 A magnetic random access memory (MRAM) cell structure, comprising: a transistor, comprising a gate, a source and a drain; a magnetic tunnel junction (MTJ) device, the MTJ device comprises at least one free layer, an insulating layer and a fixed layer, wherein the insulating layer is disposed between the free layer and the fixed layer, and the free layer is located above the insulating layer, wherein the free layer of the MTJ device is electrically connected to a bit line (BL), the fixed layer of the MTJ device is electrically connected to the source of the transistor, and the drain of the transistor is electrically connected to a sense line (SL), wherein the MTJ device further comprises an upper electrode located at a topmost layer of the MTJ device, and wherein the upper electrode has a semi-oval profile; and a first conductive via, directly contacting the MTJ device, wherein the material of the first conductive via comprises tungsten. ### Claim 2 (depends on 1) The magnetic random access memory cell structure of claim 1, wherein the MTJ device has a trapezoidal profile. ### Claim 3 (depends on 1) The magnetic random access memory cell structure of claim 1, wherein the MTJ device further includes a lower electrode located at a bottommost layer of the MTJ device, and wherein the lower electrode has a trapezoidal profile. ### Claim 4 (depends on 3) The magnetic random access memory cell structure of claim 3, wherein the first conductive via directly contacts the lower electrode. ### Claim 5 (depends on 3) The magnetic random access memory cell structure of claim 3, further comprising a second conductive via directly contacting the upper electrode. ### Claim 6 (depends on 5) The magnetic random access memory cell structure of claim 5, wherein the material of the second conductive via comprises copper. ### Claim 7 (depends on 5) The magnetic random access memory cell structure of claim 5, further comprising a spacer covering the upper electrode, the MTJ device, and the lower electrode, wherein the second conductive via penetrates through a portion of the spacer. ### Claim 8 (depends on 1) The magnetic random access memory cell structure of claim 1, wherein the first conductive via comprises a first portion and a second portion, wherein the first portion is disposed on the second portion, the first portion has an inverted trapezoidal profile, and the second portion has a rectangular profile. ### Claim 9 A magnetic random access memory (MRAM) cell structure, comprising: a transistor, comprising a gate, a source and a drain; a magnetic tunnel junction (MTJ) device, the MTJ device comprises at least one free layer, an insulating layer and a fixed layer, wherein the insulating layer is disposed between the free layer and the fixed layer, and the free layer is located above the insulating layer, wherein the free layer of the MTJ device is electrically connected to the drain of the transistor, the fixed layer of the MTJ device is electrically connected to a bit line, and the source of the transistor is electrically connected to a sense line (SL), wherein the MTJ device further comprises an upper electrode located at a topmost layer of the MTJ device, and wherein the upper electrode has a semi-oval profile; and a first conductive via, directly contacting the MTJ device, wherein the material of the first conductive via comprises tungsten. ### Claim 10 (depends on 9) The magnetic random access memory cell structure of claim 9, wherein the MTJ device has a trapezoidal profile. ### Claim 11 (depends on 9) The magnetic random access memory cell structure of claim 9, wherein the MTJ device further includes a lower electrode located at a bottommost layer of the MTJ device, and wherein the lower electrode has a trapezoidal profile. ### Claim 12 (depends on 11) The magnetic random access memory cell structure of claim 11, wherein the first conductive via directly contacts the lower electrode. ### Claim 13 (depends on 11) The magnetic random access memory cell structure of claim 11, further comprising a second conductive via directly contacting the upper electrode. ### Claim 14 (depends on 13) The magnetic random access memory cell structure of claim 13, wherein the material of the second conductive via comprises copper. ### Claim 15 (depends on 13) The magnetic random access memory cell structure of claim 13, further comprising a spacer covering the upper electrode, the MTJ device, and the lower electrode, wherein the second conductive via penetrates through a portion of the spacer. ### Claim 16 (depends on 9) The magnetic random access memory cell structure of claim 9, wherein the first conductive via comprises a first portion and a second portion, wherein the first portion is disposed on the second portion, the first portion has an inverted trapezoidal profile, and the second portion has a rectangular profile. ### Claim 17 (depends on 9) The magnetic random access memory cell structure of claim 9, further comprising a second metal layer, wherein a bottom surface of the MTJ device and a bottom surface of the second metal layer are aligned on a horizontal surface.