In this work,we design and fabricate AlGaN/GaN-based Schottky barrier diodes(SBDs)on a silicon substrate with a trenched n^(+)-GaN cap layer.With the developed physical models,we find that the n^(+)-GaN cap layer prov...In this work,we design and fabricate AlGaN/GaN-based Schottky barrier diodes(SBDs)on a silicon substrate with a trenched n^(+)-GaN cap layer.With the developed physical models,we find that the n^(+)-GaN cap layer provides more electrons into the AlGaN/GaN channel,which is further confirmed experimentally.When compared with the reference device,this increases the two-dimensional electron gas(2DEG)density by two times and leads to a reduced specific ON-resistance(Ron,sp)of~2.4 mΩ·cm^(2).We also adopt the trenched n^(+)-GaN structure such that partial of the n^(+)-GaN is removed by using dry etching process to eliminate the surface electrical conduction when the device is set in the off-state.To suppress the surface defects that are caused by the dry etching process,we also deposit Si_(3)N_(4)layer prior to the deposition of field plate(FP),and we obtain a reduced leakage current of~8×10^(−5)A·cm^(−2)and breakdown voltage(BV)of 876 V.The Baliga’s figure of merit(BFOM)for the proposed structure is increased to~319 MW·cm^(−2).Our investigations also find that the pre-deposited Si_(3)N_(4)layer helps suppress the electron capture and transport processes,which enables the reduced dynamic R_(on,sp).展开更多
基金supported by National Natural Science Foundation of China under grant U23A20361Key Area R&D Program of Guangdong Province under grant 2022B0701180001.
文摘In this work,we design and fabricate AlGaN/GaN-based Schottky barrier diodes(SBDs)on a silicon substrate with a trenched n^(+)-GaN cap layer.With the developed physical models,we find that the n^(+)-GaN cap layer provides more electrons into the AlGaN/GaN channel,which is further confirmed experimentally.When compared with the reference device,this increases the two-dimensional electron gas(2DEG)density by two times and leads to a reduced specific ON-resistance(Ron,sp)of~2.4 mΩ·cm^(2).We also adopt the trenched n^(+)-GaN structure such that partial of the n^(+)-GaN is removed by using dry etching process to eliminate the surface electrical conduction when the device is set in the off-state.To suppress the surface defects that are caused by the dry etching process,we also deposit Si_(3)N_(4)layer prior to the deposition of field plate(FP),and we obtain a reduced leakage current of~8×10^(−5)A·cm^(−2)and breakdown voltage(BV)of 876 V.The Baliga’s figure of merit(BFOM)for the proposed structure is increased to~319 MW·cm^(−2).Our investigations also find that the pre-deposited Si_(3)N_(4)layer helps suppress the electron capture and transport processes,which enables the reduced dynamic R_(on,sp).
