【摘要】 采用原子层沉积（Atomic layer deposition,ALD）技术,在（001）晶面的单晶金刚石衬底上制备了不同沉积温度Al₂O₃栅介质的氢终端金刚石MOSFET器件。在200℃下沉积Al₂O₃栅介质的器件的饱和电流密度为291 mA/mm,当沉积温度升高至300℃时,器件的饱和电流密度大幅度提高至504 mA/mm,提高了73%。同时,升高沉积温度后,器件还具有更低的导通电阻、更高的跨导和更大的阈值电压,表明该器件具有更高的载流子浓度,这与300℃下沉积的Al₂O₃中具有更多的负电荷有关。对两种器件的小信号特性进行了研究,发现将ALD Al₂O₃的沉积温度从200℃升高至300℃后,器件的截止频率f_T和最大振荡频率f_max也得到了提升,表明采用高温ALD Al₂O₃沉积技术可以显著提升金刚石MOSFET器件的电流密度和频率性能。更多还原

【Abstract】 Hydrogen-terminated diamond MOSFETs with Al₂O₃ gate dielectrics deposited at different temperatures by atomic layer deposition（ALD） technique have been fabricated on（001）-oriented single crystal diamond substrates.The device with gate dielectric deposited at 200℃ exhibited a saturation current density of 291 mA/mm.With the deposition temperature increased to 300℃,the saturation current density was significantly improved to 504 mA/mm,resulting in an increase of 73%.Additionally,by increasing the deposition temperature,the device demonstrated a lower on-resistance,a higher transconductance,as well as a larger threshold voltage,indicating the device has a higher carrier concentration.This phenomenon is primarily attributed to the presence of more negative charges in the Al₂O₃ deposited at 300℃.The small-signal characteristics of the two kinds of devices were investigated,and it was found that the cut-off frequency f_T and the maximum oscillation frequency f_max were also improved with the deposition temperature of ALD Al₂O₃ increased from 200℃ to 300℃.It implies that the current density and frequency performance of the diamond MOSFETs can be significantly improved by using the high temperature ALD Al₂O₃ deposition technique.更多还原