소스 연결 필드 플레이트 최적화를 통한 AlGaN/GaN 고전자 이동도 트랜지스터 동작 특성 향상 연구 = A Study on Improvement of Operational Characteristics in AlGaN/GaN High-Electron-Mobility Transistor by Optimizing Source-connected Field Plate

다국어 초록 (Multilingual Abstract)

In this study, we investigate the operational characteristics of AlGaN/GaN high-electron-mobility transistors（HEMTs） by varying source-connected field plate configuration. We propose an optimal field plate structure to achieve high-performance while ensuring reliable operation. Prior to the analysis, simulation parameters were calibrated to measured data from fabricated 0.15 μm planar-gate AlGaN/GaN HEMTs to ensure the simulation reliability. The top source-connected field plate length（LTSFP） was varied as the primary design parameter controlling the overall source-connected field plate configuration. Specifically, LTSFP was adjusted by shifting the source-side edge of the field plate, while the distance between the drain contact and the drain-side edge of the field plate was fixed. Subsequently, we compared and analyzed the influence of varying LTSFP on the DC, RF, and dynamic performance of AlGaN/GaN HEMTs through TCAD simulation. It was found that the breakdown voltage increased from 105.16 V at LTSFP = 0.1 μm to a peak value of 114.98 V at 0.5 μm, beyond which it converged at approximately 114.76 V. Conversely, as LTSFP decreased from 1.4 μm to 0.5 μm, the cut-off frequency increased from 36.01 GHz to 46.14 GHz. However, further reduction of LTSFP below 0.5 μm yielded only marginal improvements. Moreover, the dynamic performance metrics, characterized by current collapse and dynamic on-resistance, improved with increasing LTSFP, but reached a saturation point beyond LTSFP = 0.5 μm. Therefore, a comprehensive consideration of breakdown voltage, cut-off frequency, and dynamic performances indicates that an LTSFP of 0.5 μm represents the optimal field plate structure. These findings will help to determine the source-connected field plate geometry of the device. Consequently, AlGaN/GaN HEMTs with an optimized field plate structure are expected to demonstrate excellent performance and reliable operation in high-power and high-frequency conditions.

목차 (Table of Contents)

• 제1장 서 론 1
• 제1절 연구 배경 1
• 제2절 연구 목적 2
• 제3절 연구 구성 4
• 제2장 이론적 배경 5
• 제1절 소재 5
• 1. SiC 물질적 특성 5
• 2. GaN 물질적 특성 7
• 제2절 AlGaN/GaN 이종접합 8
• 1. AlGaN/GaN 분극 효과 8
• 2. 2-DEG 형성 메커니즘 15
• 제3절 항복 메커니즘 18
• 제4절 트래핑 메커니즘 19
• 1. 게이트-드레인 접근 영역의 표면 트랩 20
• 2. AlGaN 장벽층 내 트랩 21
• 3. GaN 버퍼층 내 트랩 22
• 제3장 AlGaN/GaN HEMT 소자 시뮬레이션 결과 및 분석 23
• 제1절 AlGaN/GaN HEMT 소자 공정 프로세스 23
• 제2절 TCAD 시뮬레이션 파라미터 및 모델 25
• 제3절 소자 동작 특성 시뮬레이션 결과 및 분석 29
• 1. 시뮬레이션 신뢰성 확보 29
• 2. 소스 연결 필드 플레이트 구조 비교 분석 32
• 3. 소스 연결 필드 플레이트 구조에 따른 DC 특성 비교 분석 33
• 4. 소스 연결 필드 플레이트 구조에 따른 RF 특성 비교 분석 35
• 5. 소스 연결 필드 플레이트 구조에 따른 동적 특성 비교 분석 38
• 제4장 논 의 44
• 제5장 결 론 46
• 참 고 문 헌 47
• ABSTRACT 56