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利用金属有机物化学气相沉积技术在蓝宝石衬底上制备了掺Fe高阻Ga N以及Al Ga N/Ga N高电子迁移率晶体管(HEMT)结构.对Cp_2Fe流量不同的高阻Ga N特性进行了研究.研究结果表明,Fe杂质在Ga N材料中引入的Fe~(3+/2+)深受主能级能够补偿背景载流子浓度从而实现高阻,Fe杂质在Ga N材料中引入更多起受主作用的刃位错,也在一定程度上补偿了背景载流子浓度.在一定范围内,Ga N材料方块电阻随Cp_2Fe流量增加而增加,Cp_2Fe流量为100 sccm(1 sccm 1mL min)时,方块电阻增加不再明显;另外增加Cp_2Fe流量也会导致材料质量下降,表面更加粗糙.因此,优选Cp_2Fe流量为75 sccm,相应方块电阻高达×10?/,外延了不同掺Fe层厚度的Al Ga N/Ga N HEMT结构,并制备成器件.HEMT器件均具有良好的夹断以及栅控特性,并且增加掺Fe层厚度使得HEMT器件的击穿电压提高了39.3%,同时对器件的转移特性影响较小.
High-resistance doped GaN and AlGaN / GaN high electron mobility transistor (HEMT) structures were fabricated on a sapphire substrate by metal-organic chemical vapor deposition. The high-resistivity Ga N characteristics with different flow rates of Cp 2 Fe were investigated The results show that Fe ~ (3 + / 2 +) deep acceptor level introduced into GaN material can compensate the background carrier concentration to achieve high resistance, and Fe impurities introduce more into GaN material The edge effect of host edge dislocation also compensates for the background carrier concentration to a certain degree.With a certain range, the sheet resistance of Ga N material increases with the increase of Cp 2 Fe flow rate, the flow rate of Cp 2 Fe is 100 sccm (1 sccm 1 mL min) , The sheet resistance increase is no longer noticeable.Adding Cp_2Fe flow rate also leads to the decrease of material quality and the rougher surface.Therefore, it is preferable that the flow rate of Cp_2Fe is 75 sccm and the corresponding sheet resistance is up to × 10? /, AlGa N / Ga N HEMT structure and prepared into devices.HEMT devices have good pinch off and gate control characteristics, and increasing the thickness of Fe-doped HEMT device allows the breakdown voltage increased by 39.3%, while the transfer of devices Features have less effect.