Table of Contents
Preface to the Reissue of the Materials Characterization Series ix
Preface to Series x
Preface to the Reissue of Characterization of Compound Semiconductor Processing xi
Preface xiii
Contributors xv
Characterization of III-V Thin Films for Electronic Devices
1.1 Introduction 1
1.2 Surface Characterization of GaAs Wafers 2
Dislocations 3
Surface Composition and Chemical State 4
1.3 Ion Implantation 6
1.4 Epitaxial Crystal Growth 11
1.5 Summary 13
III-V Compound Semiconductor Films for Optical Applications
2.1 Introduction 17
2.2 Growth Rate/Layer Thickness 20
In Situ Growth Monitors 20
Post-Growth Structural Analysis 22
2.3 Composition Analysis 23
2.4 Impurity and Dopant Analysis 27
2.5 Electrical Properties in Optical Structures 28
2.6 Optical Properties in Single and Multilayer Structures 33
2.7 Interface Properties in Multilayer Structures 35
2.8 Summary 37
3.1 Introduction 41
3.2 In Situ Probes 44
Surface Preparation and Characterization 44
Initial Metal Deposition 45
Subsequent Metal Deposition 48
3.3 Unpatterned Test Structures 48
Electrical Characterization 48
Concentration Profiling 49
Electron Microscopy 49
3.4 Patterned Test Structures 51
Barrier Height 51
Contact Resistance 53
Morphology 54
Dielectric Insulating Layers
4.1 Introduction 57
4.2 Oxides and Oxidation 58
4.3 Heteromorphic Insulators 60
4.4 Chemical Modification of GaAs Surfaces 61
4.5 Indium Phosphide-Insulator Interfaces 64
4.6 Heterojunction Quasi-Insulator Interfaces 68
4.7 Epitaxial Fluoride Insulators 72
4.8 Commentary 74
Other Compound Semiconductor Films
5.1 Introduction 83
A Focus on HgCdTe 83
Objective and Scope 84
Background 84
Representative Device Structure 86
5.2 Substrates and the CdTe Surface (Interface 1) 86
Substrate Quality 86
Substrate Surface Preparation 87
5.3 Epitaxial HgCdTe Materials (Between Interfaces 2 and 5) 90
Desired Characteristics of the Active Layers 90
Composition 90
Crystalline Quality 91
Doping 93
Minority Carrier Lifetime 96
5.4 Heterojunction Interfaces (Interface 3) 98
Advantages of the Heterojunction 98
Desired Characteristics 98
Characterizations 99
5.5 HgCdTe Surface Preparation (Interfaces 4 and 5) 100
Importance of the Chemically Etched Surface 100
Monitoring of the Surface Cleanliness by Ellipsometry 101
Characterization of Thin Native Oxides on HgCdTe by XPS 102
Surface Analysis by UPS 104
5.6 Summary 105
Deep Level Transient Spectroscopy: A Case Study On GaAs
6.1 Introduction 109
6.2 DLTS Technique: General Features 110
6.3 Fabrication and Qualification of Schottky Diodes 111
6.4 DLTS System 114
6.5 DLTS Measurement Procedure 116
6.6 Data Analysis 117
DLTS Spectrum 117
Activation Energy for Thermal Emission 118
Trap Densities 120
6.7 EL2 Center 121
6.8 Summary 121
Appendix: Technique Summaries
1 Auger Electron Spectroscopy (AES) 127
2 Ballistic Electron Emission Microscopy (BEEM) 128
3 Capacitance-Voltage (C-V) Measurements 135
4 Deep Level Transient Spectroscopy (DLTS) 137
5 Dynamic Secondary Ion Mass Spectrometry (D-SIMS) 139
6 Electron Beam Induced Current (EBIC) Microscopy 140
7 Energy-Dispersive X-Ray Spectroscopy (EDS) 146
8 Focused Ion Beams (FIBs) 147
9 Fourier Transform Infrared Spectroscopy (FTIR) 151
10 Hall Effect Resistivity Measurements 152
11 Inductively Coupled Plasma Mass Spectrometry (ICPMS) 154
12 Light Microscopy 155
13 Low-Energy Electron Diffraction (LEED) 156
14 Neutron Activation Analysis (NAA) 157
15 Optical Scatterometry 158
16 Photoluminescence (PL) 159
17 Raman Spectroscopy 160
18 Reflection High-Energy Electron Diffraction (RHEED) 161
19 Rutherford Backscattering Spectrometry (RBS) 162
20 Scanning Electron Microscopy (SEM) 163
21 Scanning Transmission Electron Microscopy (STEM) 164
22 Scanning Tunneling Microscopy and Scanning Force Microscopy (STM and SFM) 165
23 Sheet Resistance and the Four Point Probe 166
24 Spreading Resistance Analysis (SRA) 175
25 Static Secondary Ion Mass Spectrometry (Static SIMS) 183
26 Surface Roughness: Measurement, Formation by Sputtering, Impact on Depth Profiling 184
27 Total Reflection X-Ray Fluorescence Analysis (TXRF) 185
28 Transmission Electron Microscopy (TEM) 186
29 Variable-Angle Spectroscopic Ellipsometry (VASE) 187
30 X-Ray Diffraction (XRD) 188
31 X-Ray Fluorescence (XRF) 189
32 X-Ray Photoelectron Spectroscopy (XPS) 190
Index 191
