Epitaxial growth and structural characterization of MgO-based magnetic

tunnel junctions and ferromagnetic/MgO/semiconductor heterostructures

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R(o

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H(Oe)

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Inte

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.u.)

time(seconds)

Fe on Fe @RT

Y.F. Chiang, K. Pi, Y. Li ,X. Tan, H. W. K. Tom and R.K. KawakamiDepartment of Physics and Astronomy, University of California, Riverside, CA 92521

Growth of MgO-based tunnel junctions Growth of FM/MgO/semiconductors heterostructuresGe, GaAs

• Layer by layer growth of MgO barrier on Fe.• TMR measured at RT and low temperature.• Use SHG to probe the Fe/MgO interfacial properties.

0 1m

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nm1

0 1m

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15nmRate:1.8 Å/Min Rate:0.6 Å/Min

Ge(100)

Ge buffer3 nm MgO

0.4m

Grow 3nm MgO at 25°C

• Grow atomically flat MgO on Ge(100), GaAs(100).• Growth rate is crucial for flatness of MgO/GaAs(100).

GaAs(100)

3 nm MgO

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rb. U

nit)

Time (seconds)

MgO on Fe at 50C, rate ~ 0.973A/min

Fe/Fe

MgO/Fe