In ferroelectric liquid crystals, phase transitions can be induced by an electric field. The current constant method allows these transition to be quickly localized and thus the（E, T） phase diagram of the studied pr...In ferroelectric liquid crystals, phase transitions can be induced by an electric field. The current constant method allows these transition to be quickly localized and thus the（E, T） phase diagram of the studied product can be obtained.In this work, we make a slight modification to the measurement principles based on this method. This modification allows the characteristic parameters of ferroelectric liquid crystal to be quantitatively measured. The use of a current square signal highlights a phenomenon of ferroelectric hysteresis with remnant polarization at null field, which points out an effect of memory in this compound.展开更多
SiC MOSFET栅极氧化物附近存在的陷阱缺陷造成其在高温高压场景下出现许多可靠性问题。提出了完整的基于瞬态电流法的陷阱表征方案,结合贝叶斯迭代反卷积算法实现对陷阱位置、时间常数和激活能的表征。基于自建陷阱测试平台在栅极和漏...SiC MOSFET栅极氧化物附近存在的陷阱缺陷造成其在高温高压场景下出现许多可靠性问题。提出了完整的基于瞬态电流法的陷阱表征方案,结合贝叶斯迭代反卷积算法实现对陷阱位置、时间常数和激活能的表征。基于自建陷阱测试平台在栅极和漏极施加不同组合的电学偏置,表征了微秒量级的两个陷阱,其时间常数分别为2×10^(-5)s和2.5×10^(-4)s,并观察到SiC MOSFET中存在同时受栅源电压和漏源电压影响的陷阱,这种现象在沟槽型器件中尤其显著,根据此特性可以分析陷阱的位置。本研究丰富了陷阱表征的信息,为陷阱的定位和表征提供了新的思路。展开更多
文摘In ferroelectric liquid crystals, phase transitions can be induced by an electric field. The current constant method allows these transition to be quickly localized and thus the（E, T） phase diagram of the studied product can be obtained.In this work, we make a slight modification to the measurement principles based on this method. This modification allows the characteristic parameters of ferroelectric liquid crystal to be quantitatively measured. The use of a current square signal highlights a phenomenon of ferroelectric hysteresis with remnant polarization at null field, which points out an effect of memory in this compound.
