Comparisons are performed to study the drive current of accumulation-mode（AM） p-channel wrap-gated Fin-FETs.The drive current of the AM p-channel FET is 15%-26%larger than that of the inversion-mode （IM） p-channel...Comparisons are performed to study the drive current of accumulation-mode（AM） p-channel wrap-gated Fin-FETs.The drive current of the AM p-channel FET is 15%-26%larger than that of the inversion-mode （IM） p-channel FET with the same wrap-gated fin channel,because of the body current component in the AM FET, which becomes less dominative as the gate overdrive becomes larger.The drive currents of the AM p-channel wrap-gated Fin-FETs are 50%larger than those of the AM p-channel planar FETs,which arises from effective conducting surface broadening and volume accumulation in the AM wrap-gated Fin-FETs.The effective conducting surface broadening is due to wrap-gate-induced multi-surface conduction,while the volume accumulation,namely the majority carrier concentration anywhere in the fin cross section exceeding the fin doping density,is due to the coupling of electric fields from different parts of the wrap gate.Moreover,for AM p-channel wrap-gated Fin-FETs, the current in channel along 110 is larger than that in channel along 100,which arises from the surface mobility difference due to different transport directions and surface orientations.That is more obvious as the gate overdrive becomes larger,when the surface current component plays a more dominative role in the total current.展开更多
The multi-step rapid thermal annealing process of Ti/Al/Ni/Au can make good ohmic contacts with both low contact resistance and smooth surface morphology for AlGaN/GaN HEMTs.In this work,the mechanism of the multi-ste...The multi-step rapid thermal annealing process of Ti/Al/Ni/Au can make good ohmic contacts with both low contact resistance and smooth surface morphology for AlGaN/GaN HEMTs.In this work,the mechanism of the multi-step annealing process is analyzed in detail by specific experimental methods.The experimental results show that annealing temperature and time are very important parameters when optimizing the Ti/Al layer for lower resistance and the Ni/Au layer for smooth surface morphology.It is very important for good ohmic contacts to balance the rate of various reactions by adjusting the annealing temperature and time.We obtained a minimum specific contact resistance of 3.22×10^（17）Ω·cm^2 on the un-doped AlGaN/GaN structure with an optimized multistep annealing process.展开更多
基金Project supported by the National High Technology Research and Development Program of China(No.2007AA03Z303)the National Basic Research Program of China(No.2010CB934104)
文摘Comparisons are performed to study the drive current of accumulation-mode（AM） p-channel wrap-gated Fin-FETs.The drive current of the AM p-channel FET is 15%-26%larger than that of the inversion-mode （IM） p-channel FET with the same wrap-gated fin channel,because of the body current component in the AM FET, which becomes less dominative as the gate overdrive becomes larger.The drive currents of the AM p-channel wrap-gated Fin-FETs are 50%larger than those of the AM p-channel planar FETs,which arises from effective conducting surface broadening and volume accumulation in the AM wrap-gated Fin-FETs.The effective conducting surface broadening is due to wrap-gate-induced multi-surface conduction,while the volume accumulation,namely the majority carrier concentration anywhere in the fin cross section exceeding the fin doping density,is due to the coupling of electric fields from different parts of the wrap gate.Moreover,for AM p-channel wrap-gated Fin-FETs, the current in channel along 110 is larger than that in channel along 100,which arises from the surface mobility difference due to different transport directions and surface orientations.That is more obvious as the gate overdrive becomes larger,when the surface current component plays a more dominative role in the total current.
基金supported by the National Basic Research Program of China(No.2010CB934104)
文摘The multi-step rapid thermal annealing process of Ti/Al/Ni/Au can make good ohmic contacts with both low contact resistance and smooth surface morphology for AlGaN/GaN HEMTs.In this work,the mechanism of the multi-step annealing process is analyzed in detail by specific experimental methods.The experimental results show that annealing temperature and time are very important parameters when optimizing the Ti/Al layer for lower resistance and the Ni/Au layer for smooth surface morphology.It is very important for good ohmic contacts to balance the rate of various reactions by adjusting the annealing temperature and time.We obtained a minimum specific contact resistance of 3.22×10^（17）Ω·cm^2 on the un-doped AlGaN/GaN structure with an optimized multistep annealing process.
