Presentation Information
[22a-P01-17]Effect of channel crystallinity on magnetoresistance in silicon-inserted magnetic tunnel junctions
Tatsuki Watanabe1, 〇Minori Goto1,2,3,4, Yuichiro Ando5, Tsubasa Watakabe1, Hikaru Nomura1,2,3, Yoshishige Suzuki1,2,3,4 (1.Osaka Univ., 2.CSRN Osaka Univ., 3.OTRI Osaka Univ., 4.Univ. of Fukui, 5.Kyoto Univ.)
Keywords:
magnetic tunnel junctions,silicon,magnetoresistance effect
Silicon spin valve has been attracting attention in the view point of the realization for low-power-consumption devices such as spin-MOSFET [1]. High magnetoresistance (MR) ratio is required for realization of them, however, the MR ratio have been up to approximately 1% in the lateral spin valve system with Si-channel [2]. To improve the MR ratio, the vertical spin valve is desirable because it can shorten the channel length. Spin-valve with Si-channel is promising since Si have high compatibility with conventional MOS technology [3] and long spin lifetime [4], while the electric property strongly depends on the channel crystallinity. In this study, we fabricated Si-based vertical spin valve by inserting Si in magnetic tunnel junctions and evaluated the dependence of channel crystallinity on the MR properties.
The Si-inserted magnetic tunnel junction consisting of MgO(5) | Fe(30) | MgO(1.2) | Si(tSi) | MgO(1.2) | Fe(10) | Co(5) | Au(10) (described by nm) was fabricated on a single crystal MgO(001) substrate by molecular beam epitaxy, photolithography, Ar-ion milling, and lift-off methods. The MgO (1.2) was inserted at the Fe and Si interface for efficient spin injection. The Si layer was grown at room temperature and 550 °C. The temperature was determined by the temperature dependence of RHEED patterns of Si(5) surface deposited on MgO as shown in Figs 1(a) and 1(b). From this result, we found that Si-inserted layer becomes amorphous and polycrystal in the case of low and high temperature deposition, respectively. The magnetic field H was applied parallel to the film plane in [100] direction of Fe. We found that the MR ratio is improved by crystallization of Si-inserted channel as shown in Fig 2. This research was supported by JST A-STEP JPMJTR20RN and JSPS Grant-in-Aid for Scientific Research (S) Grant Number JP20H05666 and JP23H01838.
The Si-inserted magnetic tunnel junction consisting of MgO(5) | Fe(30) | MgO(1.2) | Si(tSi) | MgO(1.2) | Fe(10) | Co(5) | Au(10) (described by nm) was fabricated on a single crystal MgO(001) substrate by molecular beam epitaxy, photolithography, Ar-ion milling, and lift-off methods. The MgO (1.2) was inserted at the Fe and Si interface for efficient spin injection. The Si layer was grown at room temperature and 550 °C. The temperature was determined by the temperature dependence of RHEED patterns of Si(5) surface deposited on MgO as shown in Figs 1(a) and 1(b). From this result, we found that Si-inserted layer becomes amorphous and polycrystal in the case of low and high temperature deposition, respectively. The magnetic field H was applied parallel to the film plane in [100] direction of Fe. We found that the MR ratio is improved by crystallization of Si-inserted channel as shown in Fig 2. This research was supported by JST A-STEP JPMJTR20RN and JSPS Grant-in-Aid for Scientific Research (S) Grant Number JP20H05666 and JP23H01838.