목차

1. Introduction 1
2. Theoretical Background 4
2.1 Nitride Semiconductors 4
2.2 AlGaN/GaN Heterostructure 7
2.2.1 Spontanesou and Piezoelectric Polarization 9
2.2.2 Conduction Band Discontinuity 11
2.3 Conventional Biosensors 12
2.3.1 Electrochemical Sensors 14
2.3.2 Optical Sensors 15
2.3.3 Mass Sensitive Sensors 16
2.4 FET-Type Biosensors 17
2.4.1 Principles of FET Operation 17
2.4.2 Si-Based MOSFETs vs. AlGaN/GaN-Based HFETs 20
2.4.3 Principles of FET-Type Biosensor for Protein Detection 22
3. AlGaN/GaN-Based HFET-Type Biosensors for Detection of CRP 26
3.1 AlGaN/GaN HFET-Type Biosensor with Null-Balancing Circuit 26
3.1.1 Motivation 26
3.1.2 Device Structure and Fabrication 28
3.1.2 Reagents and Bio-Experiment Procedures 30
3.1.3 Null-Balancing Circuit 31
3.1.4 Verification of SAM Formation 33
3.1.5 Electrical Characteristics of a Null-Balancing Circuit Applied HFET-Type Biosensor 35
3.2 AlGaN/GaN-Based Differential-Mode HFET-Type Biosensor 45
3.2.1 Motivation 45
3.2.2 Device Structure and Fabrication 47
3.2.3 Operational Priciple of Differential-Mode Biosensor 49
3.2.4 Reagents and Bio-Experiment Procedures 51
3.2.5 Verification of 11-MUA Immobilization 52
3.2.6 I-V Characteristics of the Bio-HFET 54
3.2.7 Noise Reduction Characteristics of the Differential-Mode Biosensor 57
3.2.8 Real-Time Detection of CRP 60
3.2.9 Output Voltage Characteristics of Differential-Mode Biosensor with Respect to CRP Concentration 62
4. AlGaN/GaN-Based Extended-Gate HFET-Type Biosensor 64
4.1 Motivation 66
4.2 Device Fabrication 66
4.3 Measurement Setup 71
4.4 Reagents and Bio-Experiment Procedures 72
4.5 I-V Characteristics of Extended-Gate HFET-Type Biosensor 73
4.6 Verification of 16-MHDA Immobilization 79
5. Conclusion 82
6. References 84
Abstract in Korean 96
List of Pubilications 98