The advent of an era characterized by intelligent, interconnected systems of AlGaN/GaN High Electron Mobility Transistors (HEMTs) electronic devices is underway. Within this context, the performance of ohmic contacts in HEMTs bears substantive influence on the electrical characteristics of power devices, notably impacting parameters such as on-resistance and output current. Therefore, the improvement of ohmic contacts attributes in AlGaN/GaN HEMT devices has perennially constituted a focal point of considerable industry. Based on the AlGaN/GaN heterostructure, a novel TiAl/Au ohmic contact has been successfully developed for HEMTs. A low contact resistance of 0.23 Ω·mm (2.33 × 10 Ω·cm) is obtained, which proposes a new interface contact for AlGaN/GaN heterojunction. Transmission electron microscope (TEM) illustrates that the contact mechanism for low resistance is direct contact with two-dimensional electron gas (2DEG) through the substitution of the TiN compound with a smaller area Au dominated penetration. Concurrently, in contrast to TiN, Au exhibits a diminished capacity for Ga dissolution, thereby substantiating its efficacy in preserving the structural integrity of the crystal lattice. In addition, the reduction of Al can impede the diffusion notably, further showing the smooth surface morphology of the electrode with atomic force microscope (AFM) and scanning electron microscopy (SEM) measurements. The ohmic contacts of HEMTs are individually fabricated with Ti/Al/Ni/Au and TiAl/Au configurations. The HEMTs with TiAl/Au ohmic contacts demonstrate superior DC characteristics.

中文翻译：

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低电阻 TiAl3/Au 欧姆接触和 AlGaN/GaN HEMT 的增强性能


以 AlGaN/GaN 高电子迁移率晶体管 (HEMT) 电子器件智能互连系统为特征的时代即将到来。在此背景下，HEMT中欧姆接触的性能对功率器件的电气特性产生实质性影响，特别是影响导通电阻和输出电流等参数。因此，AlGaN/GaN HEMT器件欧姆接触属性的改善一直是业界关注的焦点。基于AlGaN/GaN异质结构，成功开发了一种用于HEMT的新型TiAl/Au欧姆接触。获得了 0.23 Ω·mm (2.33 × 10 Ω·cm) 的低接触电阻，为 AlGaN/GaN 异质结提出了一种新的界面接触。透射电子显微镜（TEM）表明，低电阻的接触机制是通过用较小面积的Au主导渗透代替TiN化合物与二维电子气（2DEG）直接接触。同时，与 TiN 相比，Au 的 Ga 溶解能力减弱，从而证实了其在保持晶格结构完整性方面的功效。此外，Al的还原可以显着阻碍扩散，原子力显微镜（AFM）和扫描电子显微镜（SEM）测量进一步显示电极的光滑表面形貌。 HEMT 的欧姆接触采用 Ti/Al/Ni/Au 和 TiAl/Au 配置单独制造。具有 TiAl/Au 欧姆接触的 HEMT 表现出优异的直流特性。