High-Efficiency Nitride-based Power Devices in the Next Generation

该项目的目的是证明III族氮化物是制造下一代高功率场效应管的最合适材料之一。在2006财年，1。1 .通过表面钝化降低电阻，提高互导率；2 .逆变电路亚阈值摆幅小，功耗低；通过改变势垒组成和厚度来控制阈值电压的可控性；澄清了栅极源和栅极下迁移率的差异。为了实现高功率器件，AN衬底由于晶格失配小和电阻极高而非常有前景。因此，在这个程序中，5。6.在6H-SiC衬底上升华生长AIN衬底；采用高温MOVPE法在蓝宝石衬底上生长高质量的AIN模板。这一期发表了几篇论文。2007财年，发现了SiN钝化膜厚度与最大漏极电流之间的关系。通过优化SIN厚度为5 nm，可以在正常关闭的JHFET中成功观察到以下性能：最大漏极电流密度：1.58×10^<-1> [A/mm]，漏电流：1.45×10^<-8> [A/mm]，通/关比：大于7个数量级，亚阈值摆幅：90 [mV/dec]。]，阻力：3.4 [mΩcm^2]。此外，击穿电压高达325 V，足以满足小型空调的逆变电路。

Objective of this program is to prove that the group III nitride is one of the most suitable materials for the fabrication of high power FET in the next generation. In FY2006, 1. Reduction of on resistance and improvement of the mutual conductance by surface passivation, 2. Small sub-threshold swing and low power loss in inverter circuit, 3. Controllability of the threshold voltage by changing barrier composition and thickness, and 4. Difference of the mobility underneath the gate-source and the gate were clarified. In order to realize high power devices, AN substrate is very promising because of the small lattice mismatch and the extremely high resistance. Therefore, in this program, 5. Growth of AIN substrate by sublimation on the 6H-SiC substrate, and 6. Growth of high quality AIN template on a sapphire substrate by high temperature MOVPE was conducted. Several papers were published for this issue.In FY2007, relationship between thickness of SiN passivation film and the maximum drain current was found. By optimizing the SIN thickness to be 5 nm, the following performance can be successfully observed in the normally off JHFET; Maximum drain current density: 1.58×10^<-1> [A/mm], leakage current: 1.45×10^<-8> [A/mm], on/off ratio: higher than 7 orders of magnitude, sub-threshold swing: 90 [mV/dec.], on resistance: 3.4 [mΩcm^2]. In addition, breakdown voltage was as high as 325 V, which is sufficient for inverter circuits for small size air conditioner.