Nonuniform composition profile in In0.5Ga0.5As alloy quantum dots

被引：252

作者：

Liu, N ^{[1
]}

Tersoff, J

Baklenov, O

Holmes, AL

Shih, CK

机构：

[1] Univ Texas, Dept Phys, Austin, TX 78712 USA

[2] IBM Corp, Div Res, TJ Watson Res Ctr, Yorktown Heights, NY 10598 USA

[3] Univ Texas, Dept Elect & Comp Engn, Austin, TX 78712 USA

来源：

PHYSICAL REVIEW LETTERS | 2000年 / 84卷 / 02期

关键词：

D O I：

10.1103/PhysRevLett.84.334

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We use cross-sectional scanning tunneling microscopy to examine the shape and composition distribution of In0.5Ga0.5As quantum dots (QDs) formed by capping heteroepitaxial islands. The QDs have a truncated pyramid shape. The composition appears highly nonuniform, with an In-rich core having an inverted-triangle shape. Thus the electronic properties will be drastically altered, relative to the uniform composition generally assumed in device modeling. Theoretical analysis of the QD growth suggests a simple explanation for the unexpected shape of the In-rich core.

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页码：334 / 337

页数：4

相关论文

共 24 条

[1] Strain variations in InGaAsP/InGaP superlattices studied by scanning probe microscopy [J].

Chen, HJ ;

Feenstra, RM ;

Goldman, RS ;

Silfvenius, C ;

Landgren, G .

APPLIED PHYSICS LETTERS, 1998, 72 (14) :1727-1729

[2] Dislocation-free island formation in heteroepitaxial growth: A study at equilibrium [J].

Daruka, I ;

Barabasi, AL .

PHYSICAL REVIEW LETTERS, 1997, 79 (19) :3708-3711

[3] Cross-sectional scanning-tunneling microscopy of stacked InAs quantum dots [J].

Eisele, H ;

Flebbe, O ;

Kalka, T ;

Preinesberger, C ;

Heinrichsdorff, F ;

Krost, A ;

Bimberg, D ;

Dähne-Prietsch, M .

APPLIED PHYSICS LETTERS, 1999, 75 (01) :106-108

[4] Intermixing and shape changes during the formation of InAs self-assembled quantum dots [J].

García, JM ;

MedeirosRibeiro, G ;

Schmidt, K ;

Ngo, T ;

Feng, JL ;

Lorke, A ;

Kotthaus, J ;

Petroff, PM .

APPLIED PHYSICS LETTERS, 1997, 71 (14) :2014-2016

[5] ONSET OF INCOHERENCY AND DEFECT INTRODUCTION IN THE INITIAL-STAGES OF MOLECULAR-BEAM EPITAXIAL-GROWTH OF HIGHLY STRAINED INXGA1-XAS ON GAAS(100) [J].

GUHA, S ;

MADHUKAR, A ;

RAJKUMAR, KC .

APPLIED PHYSICS LETTERS, 1990, 57 (20) :2110-2112

[6] Self-organized quantum dots and quantum dot lasers (invited) [J].

Ishikawa, H ;

Shoji, H ;

Nakata, Y ;

Mukai, K ;

Sugawara, M ;

Egawa, M ;

Otsuka, N ;

Sugiyama, Y ;

Futatsugi, T ;

Yokoyama, N .

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1998, 16 (02) :794-800

[7] Scanning tunneling microscopy and scanning tunneling spectroscopy of self assembled InAs quantum dots [J].

Legrand, B ;

Grandidier, B ;

Nys, JP ;

Stievenard, D ;

Gerard, JM ;

Thierry-Mieg, V .

APPLIED PHYSICS LETTERS, 1998, 73 (01) :96-98

[8] DIRECT FORMATION OF QUANTUM-SIZED DOTS FROM UNIFORM COHERENT ISLANDS OF INGAAS ON GAAS-SURFACES [J].

LEONARD, D ;

KRISHNAMURTHY, M ;

REAVES, CM ;

DENBAARS, SP ;

PETROFF, PM .

APPLIED PHYSICS LETTERS, 1993, 63 (23) :3203-3205

[9] Indium segregation and enrichment in coherent InxGa1-xAs/GaAs quantum dots [J].

Liao, XZ ;

Zou, J ;

Cockayne, DJH ;

Leon, R ;

Lobo, C .

PHYSICAL REVIEW LETTERS, 1999, 82 (25) :5148-5151

[10] Alloy ordering in GaInP alloys: A cross-sectional scanning tunneling microscopy study [J].

Liu, N ;

Shih, CK ;

Geisz, J ;

Mascarenhas, A ;

Olson, JM .

APPLIED PHYSICS LETTERS, 1998, 73 (14) :1979-1981