The influence of Fermi level pinning/depinning on the Schottky barrier height and contact resistance in Ge/CoFeB and Ge/MgO/CoFeB structures

被引：48

作者：

Lee, Donkoun ^{[1
]}

Raghunathan, Shyam ^{[2
]}

Wilson, Robert J. ^{[1
]}

Nikonov, Dmitri E. ^{[3
]}

Saraswat, Krishna ^{[2
]}

Wang, Shan X. ^{[1
,2
]}

机构：

[1] Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA

[2] Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA

[3] Intel Corp, Components Res, Santa Clara, CA 95052 USA

来源：

APPLIED PHYSICS LETTERS | 2010年 / 96卷 / 05期

关键词：

boron alloys; cobalt alloys; contact resistance; Fermi level; germanium; interface states; iron alloys; magnesium compounds; MIS structures; Schottky barriers; spin polarised transport; SPIN INJECTION; FERROMAGNETIC METAL;

D O I：

10.1063/1.3285163

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We demonstrated that an ultrathin MgO layer between CoFeB and Ge modulated the Schottky barrier heights and contact resistances of spin diodes. We confirmed that, surprisingly, an insulating MgO layer significantly decreased the Schottky barrier heights and contact resistances of spin diodes on N+Ge, opposite to the increase observed for P+Ge. A 0.5 nm thick MgO layer on N+Ge decreases the Schottky barrier height from 0.47 to 0.05 eV and lowers the minimum contact resistance 100-fold to 1.5x10(-6) m(2). These results open a pathway for high efficient spin injection from ferromagnetic materials and semiconductors.

引用

页数：3

共 17 条

[1] Current-voltage characteristics of Schottky barriers with barrier heights larger than the semiconductor band gap:: The case of NiGe/n-(001)Ge contact -: art. no. 113706 [J].

Chi, DZ ;

Lee, RTP ;

Chua, SJ ;

Lee, SJ ;

Ashok, S ;

Kwong, DL .

JOURNAL OF APPLIED PHYSICS, 2005, 97 (11)

[2] New route to zero-barrier metal source/drain MOSFETs [J].

Connelly, D ;

Faulkner, C ;

Grupp, DE ;

Harris, JS .

IEEE TRANSACTIONS ON NANOTECHNOLOGY, 2004, 3 (01) :98-104

[3] Fermi-level pinning and charge neutrality level in germanium [J].

Dimoulas, A. ;

Tsipas, P. ;

Sotiropoulos, A. ;

Evangelou, E. K. .

APPLIED PHYSICS LETTERS, 2006, 89 (25)

[4] Conditions for efficient spin injection from a ferromagnetic metal into a semiconductor -: art. no. 184420 [J].

Fert, A ;

Jaffrès, H .

PHYSICAL REVIEW B, 2001, 64 (18)

[5] Spin injection from a ferromagnetic metal into a semiconductor [J].

Jaffrès, H ;

Fert, A .

JOURNAL OF APPLIED PHYSICS, 2002, 91 (10) :8111-8113

[6]

Kobayashi S, 2008, S VLSI TECH, P59, DOI 10.1109/VLSIT.2008.4588569

[7]

MILLER DAB, 2008, QUANTUM MECH SCI ENG, P277

[8] Tunable spin-tunnel contacts to silicon using low-work-function ferromagnets [J].

Min, Byoung-Chul ;

Motohashi, Kazunari ;

Lodder, Cock ;

Jansen, Ron .

NATURE MATERIALS, 2006, 5 (10) :817-822

[9]

NAYFEH A, 2005, MRS SPRING C S UNPUB

[10] Evidence for strong Fermi-level pinning due to metal-induced gap states at metal/germanium interface [J].

Nishimura, Tomonori ;

Kita, Koji ;

Toriumi, Akira .

APPLIED PHYSICS LETTERS, 2007, 91 (12)

← 1 2 →