Molecular beam epitaxial growth of III-V semiconductor ... - KOBRA

More documents

Recommendations

Info

Optimization of MEE and MBE growth of GaP Buer on Silicon Substrate Figure 7.8: (5 × 5 µm 2 ) AFM images of 40 nm GaP-MBE/10 nm GaP-MEE /Si. The RMS value is 1.3 nm without growth stop and with increased Ga growth rate from 100 nm to 300 nm during the growth temperature ramping from MEE to MBE mode. We can conclude that the thin GaP-MEE/Si shows great promise as a virtual substrate for III-V on Si growth. These results are highly encouraging for further III-V/GaP/Si integrations for the potential applications. 126
Chapter 8 Conclusions In summary, self-assembled MBE growth of InAs and InGaAs QDs on at Si(100) has been intensively studied. Reection high energy diraction (RHEED) streak patterns conrm that the combination of the atomic hydrogen followed by thermal desorption is an ecient surface cleaning method. An additional improvement for the cleaning and growth is achieved by exposing the Si surface with Ga at low uxes resulted in a strong reduction of the lateral size of InAs QDs from 50-70 nm down to 25-30 nm and a signicant enhancement of the homogeneity of the dot size and distribution. The evolution of size, density and shape of the QDs are exsitu characterized by AFM and TEM. Dierent growth parameters such as InAs coverage, growth temperature, In-growth rate and V/III ratio are examined on dierently prepared silicon surfaces. The InAs QDs density is strongly increased from 10 8 to 10 11 cm −2 at V/III ratios in the range of 15-35 (beam equivalent pressure values). InAs QD formations are not observed at temperatures as high as 500 ◦ C. Moreover, InAs quantum dashes are observed on at higher In-growth rate of 0.3 ML/s. TEM characterizations of InAs QDs embedded in silicon matrix with dierent nominal thicknesses on dierent o-cuts substrates showed semi-coherent QDs with good crystal quality inside the dots and mist dislocations at the interface of InAs/Si. The substrate ocut found to have inuence on the QDs shape and geometry. A very homogeneous narrow QDs size with D= 5-8 nm distribution with spherical to multi-facet shape has been observed on ocut substrate, compared to a broader size distribution with D= 15-25 nm observed on exactly oriented 127
Page 1:
Molecular Beam Epitaxial Growth of
Page 4 and 5:
Gutachter (Supervisors): 1. Prof. D
Page 6 and 7:
patterns indicating a 2D smooth sur
Page 8 and 9:
(MEE = migration enhance epitaxy) u
Page 10 and 11:
viii
Page 12 and 13:
CONTENTS 3.4.4 Planar Defects Assoc
Page 14 and 15:
CONTENTS xii
Page 16 and 17:
Introduction thesis a detailed stud
Page 18 and 19:
Introduction 1.1.2 Thesis Approach
Page 20 and 21:
Introduction 1.2 Thesis Outline The
Page 22 and 23:
Theoretical Background of Semicondu
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Heteroepitaxial Growth of III-V Sem
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Experimental Growth and Characteriz
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
MBE Growth of Self-Assembled InAs a
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91: MBE Growth of Self-Assembled InAs a
Page 118 and 119: MBE Growth of InAs and InGaAs Quant
Page 130 and 131: Optimization of MEE and MBE growth
Page 142 and 143: Conclusions substrates, respectivel
Page 144 and 145: REFERENCES [8] J. M. Gerard, O. Cab
Page 146 and 147: REFERENCES [29] http://www.wmi.badw
Page 148 and 149: REFERENCES [49] M. R. Brenner: GaP/
Page 150 and 151: REFERENCES [66] Y. Ishida, T. Takah
Page 152 and 153: REFERENCES [84] A. Garcia, C. M. Ma
Page 154 and 155: REFERENCES [100] M. Felici, P. Gall
Page 156 and 157: REFERENCES [116] H. Usui, H. Yasuda
Page 158 and 159: REFERENCES [133] Grassman, T. J. Br
Page 160 and 161: Conferences Contributions: Tariq Al
Page 162 and 163: Nomenclature
Page 164 and 165: REFERENCES symbol Descriptions γ f
Page 166 and 167: like to thank all member of the Ins
Page 168: REFERENCES Erklärung Hiermit versi
show all

Molecular beam epitaxial growth of III-V semiconductor ... - KOBRA

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?