Index
Introduction . . . . 1
Thesis organization . . . . 3
Bibliography . . . . 4
1. Analysis of quantum shot noise and its suppression in chaotic cavities . . . . 6
1.1 Introduction . . . . 6
1.1.2 Coulomb blockade . . . . 7
1.1.3 Quantum dots . . . . 8
1.1.4 Pauli principle . . . . 9
1.2 Chaotic cavities . . . 10
1.3 Theories of shot noise suppression . . . 12
1.4 Cascaded chaotic cavities . . . 15
1.5 Quantum point contact . . . 16
1.6 Quantum shot noise . . . 18
1.6.1 Introduction . . . 18
1.6.2 Types of electrical noise . . . 19
1.6.3 Shot noise . . . 20
1.6.4 Quiet electrons . . . 23
1.7 Shot noise measurement . . . 24
Bibliography . . . 27
2. Device fabrication . . . 31
2.1 Introduction . . . 31
2.2 Clean room . . . 31
2.2.1 Clean room class . . . 32
2.3 Optical process technique . . . 33
2.3.1 Cleaving . . . 33
2.3.2 Cleaning . . . 34
2.3.3 Mesa photolithography . . . 34
2.3.4 Mesa etch . . . 35
2.3.5 Ohmic photolithography . . . 36
2.3.6 Ohmic metallization . . . 36
2.3.7 Annealing ohmic contacts . . . 37
2.3.8 Gates photolithography . . . 37
2.3.9 Gates metallization . . . 38
2.4 Electron beam lithography . . . 38
2.4.1 Introduction to scanning electron microscopy . . . 40
2.4.2 Electron beam generation . . . 42
2.4.3 Tungsten filament cathode . . . 42
2.4.4 Field emission gun . . . 44
2.4.5 Electron optics . . . 46
2.5 Electron beam processes . . . 48
2.6 Packaging . . . 50
2.7 Bonding . . . 50
2.8 Heterostructure . . . 52
2.8.1 Two dimensional electron gas (2-DEG) . . . 52
2.8.2 Mobility . . . 52
2.8.3 C2334 Heterostructure . . . 54
Bibliography . . . 55
3. Electrical characterization . . . 57
3.1 Introduction . . . 57
3.2 Chip carrier . . . 57
3.3 Bonded device . . . 58
3.4 Measurements set up . . . 59
3.5 4.2 K performance . . . 60
3.6 Characterization at 1.3 K . . . 66
3.7 Magnetic field operation . . . 75
Conclusions . . . 79
Bibliography . . . 80
