| 摘要: | 本研究針對氮化鎵(GaN)電晶體在高壓操作下所面臨之反向導通電壓過高與動態導通電阻劣化問題，提出一種整合型新穎結構SPGD-R-HEMT，藉由電路端整合設計有效抑制元件導通退化現象，並提升其穩定性。
SPGD-R-HEMT主要由傳統p-GaN Gate HEMT主體構成，並於其閘極端串接一顆由相同製程形成之SPGD二極體(閘極與源極短路作為陽極，汲極為陰極)，再於主體HEMT之閘極與源極間並聯一積體化2DEG電阻，作為提供放電通路與等效偏壓緩衝的結構元件。
本研究透過直流特性與脈衝模式(Pulse IV)進行元件順向導通與反向導通之靜態與動態電性評估，並延伸至高溫操作環境下之變溫分析。實驗結果顯示，相較於傳統HEMT：
1.SPGD-R-HEMT在反向導通特性方面具有明顯改善，反向導通電壓由7.25 V降低至2.25 V，有效減少導通損耗
2.在動態導通電阻(DRon)方面，SPGD-R-HEMT展現出在高偏壓下顯著穩定性，具備優異的抑制退化能力
3.在變溫操作下，SPGD-R-HEMT在閘極漏電流、臨界電壓、導通電阻與反向導通電壓等特性皆維持良好表現，顯示其結構具高度熱穩定性與實用性
因此證明SPGD-R-HEMT可作為提升氮化鎵功率元件效能的重要結構參考，適用於電源模組、功率轉換器等高效率應用領域，對於次世代GaN電晶體的發展提供有效的貢獻。;This study focus on the challenges of excessive reverse conduction voltage and dynamic on-resistance (DRon) degradation encountered in Gallium Nitride (GaN) power transistors under high-voltage operation. A novel integrated structure SPGD-R-HEMT, is proposed to mitigate conduction degradation through circuit-level design, thereby enhancing device stability.
The SPGD-R-HEMT consists of conventional p-GaN Gate HEMT as the main device, with a Schottky P-GaN Gate Diode (SPGD)—formed by shorting gate and source as the anode and using drain as the cathode—connected in series at the gate terminal. Additionally, an integrated 2DEG resistor is placed in parallel between gate and source of the main HEMT to provide a discharge path and act as an effective voltage buffer.
Comprehensive evaluations of both forward and reverse conduction characteristics were performed through DC and pulsed-mode (Pulse IV) measurements, along with temperature-dependent (up to 150 °C) electrical analyses. The experimental results reveal that, compared to conventional HEMTs:
1.The SPGD-R-HEMT demonstrates significant improvement in reverse conduction behavior, reducing the reverse conduction voltage from 7.25 V to 2.25 V, effectively lowering conduction losses.
2.In terms of DRon, the SPGD-R-HEMT shows excellent degradation suppression and enhanced stability under high off-state drain voltage conditions.
3.Under different temperatures operation, the SPGD-R-HEMT maintains superior performance in gate leakage current, threshold voltage, on-resistance, and reverse conduction voltage, indicating high thermal stability and practical applicability.
These experimental results demonstrate that the SPGD-R-HEMT is a promising structural innovation for enhancing the performance of GaN power devices, with potential applications in power modules, converters, and other high-efficiency systems, contributing meaningfully to the development of next-generation GaN transistors. |
