混合极性GaN基HEMT中2DEG性能分析  

Novel Hybrid Polar Ohmic Contacts of GaN-Based High Electron Mobility Transistor and Improvement of Two-Dimensional Electron-Gas Properties

作　　者：王现彬[1] 张晶[1] 杨洁[1] 赵正平[2] 

机构地区：[1]石家庄学院物理与电气信息工程学院,石家庄050000 [2]河北工业大学信息工程学院,天津300130

出　　处：《真空科学与技术学报》2017年第4期394-399,共6页Chinese Journal of Vacuum Science and Technology

基　　金：河北省科技计划项目(15210606);河北省高等学校科学技术研究项目(Z2017140)

摘　　要：综合镓极性(Ga-polar)和氮极性(N-polar)GaN基高电子迁移率晶体管(HEMT)上的欧姆接触特性,提出了一种混合极性的GaN基HEMT结构。通过自洽求解薛定谔方程和泊松方程,分析了该混合极性GaN基HEMT结构中的二维电子气(2DEG)行为特性,从而为该混合极性HEMT结构的实际应用提供了理论参考。仿真结果表明N-polar AlGaN背势垒的Al组分较其厚度对2DEG的影响更为明显,而将N-polar AlGaN背势垒的Al组分渐变后,可以降低寄生沟道对主沟道2DEG的影响,AlN插入层的引入也可进一步提高2DEG面密度、迁移率及其限阈性。A novel type of the GaN-based high electron mobility transistor （HEMT） structure, consisting of the hybrid Ga-polar and N-polar GaN layers, was proposed for the purposes of simplifying the fabrication of HEMT and optimizing the property of Ohmic contacts. The two-dimensional electron gas （2DEG） behavior, in the proposed HEMT structure with hybrid polar Ohmic contacts ,was empirically approximated, mathematically modeled, theoretically analyzed by self-consistently solving the Schrodinger and Poisson equations, and numerically simulated. The simulated results show that when it comes to the impact on the 2DEG density, the Al-content outweighs the depth of the AlGaN back potential-barrier. We found that a graded Al depth profile in N-polar AlGaN back potential barrier markedly weakens the influence of the parasitic channel on the 2DEG in the main channel, and that the inserted AlN nano-layer significantly improves the density,mobility and confinement of 2DEG.

关 键 词：混合极性 氮化镓 二维电子气 高电子迁移率晶体管 

分 类 号：TN386.3[电子电信—物理电子学]