| Paper Abstract and Keywords |
| Presentation |
2009-10-08 13:55
[Invited Talk]
Nonvolatile RAM using spin transfer torque magnetization reversal (SPRAM)
Hiromasa Takahashi, Kenchi Ito, Jun Hayakawa, Katsuya Miura, Hiroyuki Yamamoto, Michihiko Yamanouchi (ARL, Hitachi, Ltd.), Kazuo Ono, Riichiro Takemura, Takayuki Kawahara (CRL, Hitachi, Ltd.), Ryutaro Sasaki (RIEC Tohoku Univ.), Haruhiro Hasegawa (RIEC Tohoku Univ., ARL, Hitachi, Ltd.), Shoji Ikeda (RIEC Tohoku Univ.), Hideyuki Matsuoka (ARL, Hitachi, Ltd.), Hideo Ohno (RIEC Tohoku Univ.) |
| Abstract |
(in Japanese) |
(See Japanese page) |
| (in English) |
The SPRAM (Spin Transfer Torque MRAM) is one of nonvolatile memories that “writing” is done by that a magnetization in MTJ device was switched by current induced spin transfer torque. On the other hands, traditional MRAM writing is done by current induced magnetic field. For a traditional MRAM, it has an issue for scalability of the current that increases with diminishing the device sizes. On the contrary, SPRAM is scalable with a diminishing because its writing current is decided by the product of threshold current density and the area of a MTJ pillar. So, SPRAM has received attention for future universal memory from the viewpoint of its high speed, non-volatility, high capacity, and long endurance.
The major issue for realizing SPRAM is the compatibility of high thermal stability with low switching threshold current density. Currently, in order to solve this issue, both writing in-plane magnetized MTJ and writing perpendicular to plane magnetized MTJ are studied in many groups. Our group has made a study with an in-plane magnetized type CoFeB/MgO/CoFeB based MTJ stacks, and succeeded in making the highest magneto-resistive ratio of 604% at r.t.[1] The MTJ properties were improved due to the optimization of CoFeB concentrations, synthetic ferromagnetic structure, and optimizing fabrication processes. Thus, we fabricated the 32Mb SPRAM chips and confirmed its reading and writing performances. In this presentation, I will introduce those results and talking about the impact for this.
This work was partly supported by “High-Performance Low-Power Consumption Spin Devices and Storage Systems” program under Research and Development for Next-Generation Information Technology of MEXT.
[1] S. Ikeda, J. Hayakawa, Y. Ashizawa, Y. M. Lee, K. Miura, H. Hasegawa, M. Tsunoda, F. Matsukura, and H. Ohno, Appl. Phys. Lett. 93, 082508(2008). |
| Keyword |
(in Japanese) |
(See Japanese page) |
| (in English) |
SPRAM / MRAM / MTJ / non-volatility / thermal stability / spin transfer torque / writing in-plane magnetized MTJ / |
| Reference Info. |
IEICE Tech. Rep. |
| Paper # |
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| Download PDF |
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| Conference Information |
| Committee |
ITE-MMS MRIS |
| Conference Date |
2009-10-08 - 2009-10-09 |
| Place (in Japanese) |
(See Japanese page) |
| Place (in English) |
FUKUOKA traffic center |
| Topics (in Japanese) |
(See Japanese page) |
| Topics (in English) |
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| Paper Information |
| Registration To |
MRIS |
| Conference Code |
2009-10-MMS-MR |
| Language |
Japanese |
| Title (in Japanese) |
(See Japanese page) |
| Sub Title (in Japanese) |
(See Japanese page) |
| Title (in English) |
Nonvolatile RAM using spin transfer torque magnetization reversal (SPRAM) |
| Sub Title (in English) |
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| Keyword(1) |
SPRAM |
| Keyword(2) |
MRAM |
| Keyword(3) |
MTJ |
| Keyword(4) |
non-volatility |
| Keyword(5) |
thermal stability |
| Keyword(6) |
spin transfer torque |
| Keyword(7) |
writing in-plane magnetized MTJ |
| Keyword(8) |
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| 1st Author's Name |
Hiromasa Takahashi |
| 1st Author's Affiliation |
Advanced Research Laboratory, Hitachi, Ltd. (ARL, Hitachi, Ltd.) |
| 2nd Author's Name |
Kenchi Ito |
| 2nd Author's Affiliation |
Advanced Research Laboratory, Hitachi, Ltd. (ARL, Hitachi, Ltd.) |
| 3rd Author's Name |
Jun Hayakawa |
| 3rd Author's Affiliation |
Advanced Research Laboratory, Hitachi, Ltd. (ARL, Hitachi, Ltd.) |
| 4th Author's Name |
Katsuya Miura |
| 4th Author's Affiliation |
Advanced Research Laboratory, Hitachi, Ltd. (ARL, Hitachi, Ltd.) |
| 5th Author's Name |
Hiroyuki Yamamoto |
| 5th Author's Affiliation |
Advanced Research Laboratory, Hitachi, Ltd. (ARL, Hitachi, Ltd.) |
| 6th Author's Name |
Michihiko Yamanouchi |
| 6th Author's Affiliation |
Advanced Research Laboratory, Hitachi, Ltd. (ARL, Hitachi, Ltd.) |
| 7th Author's Name |
Kazuo Ono |
| 7th Author's Affiliation |
Central Research Laboratory, Hitachi, Ltd. (CRL, Hitachi, Ltd.) |
| 8th Author's Name |
Riichiro Takemura |
| 8th Author's Affiliation |
Central Research Laboratory, Hitachi, Ltd. (CRL, Hitachi, Ltd.) |
| 9th Author's Name |
Takayuki Kawahara |
| 9th Author's Affiliation |
Central Research Laboratory, Hitachi, Ltd. (CRL, Hitachi, Ltd.) |
| 10th Author's Name |
Ryutaro Sasaki |
| 10th Author's Affiliation |
Research Institute of Electrical Communication, Tohoku University (RIEC Tohoku Univ.) |
| 11th Author's Name |
Haruhiro Hasegawa |
| 11th Author's Affiliation |
Research Institute of Electrical Communication, Tohoku University (RIEC Tohoku Univ., ARL, Hitachi, Ltd.) |
| 12th Author's Name |
Shoji Ikeda |
| 12th Author's Affiliation |
Research Institute of Electrical Communication, Tohoku University (RIEC Tohoku Univ.) |
| 13th Author's Name |
Hideyuki Matsuoka |
| 13th Author's Affiliation |
Advanced Research Laboratory, Hitachi, Ltd. (ARL, Hitachi, Ltd.) |
| 14th Author's Name |
Hideo Ohno |
| 14th Author's Affiliation |
Research Institute of Electrical Communication, Tohoku University (RIEC Tohoku Univ.) |
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| Speaker |
Author-1 |
| Date Time |
2009-10-08 13:55:00 |
| Presentation Time |
55 minutes |
| Registration for |
MRIS |
| Paper # |
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| Volume (vol) |
vol.109 |
| Number (no) |
no.222 |
| Page |
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