According to the avalanche ionization theory,a computer-based analysis is performed to analyze the structural parameters of single-and multiple-zone junction termination extension（JTE） structures for 4H-SiC bipolar ...According to the avalanche ionization theory,a computer-based analysis is performed to analyze the structural parameters of single-and multiple-zone junction termination extension（JTE） structures for 4H-SiC bipolar junction transistors（BJTs） with mesa structure.The calculation results show that a single-zone JTE can yield high breakdown voltages if the activated JTE dose and the implantation width are controlled precisely and a multiple-zone JTE method can decrease the peak surface field while still maintaining a high blocking capability.The influences of the positive and negative surface or interface states on the blocking capability are also shown.These conclusions have a realistic meaning in optimizing the design of a mesa power device.展开更多
Based on the material characteristics and the operational principle of the double base epilayer BJTs,and according to the drift-diffusion and the carrier recombination theory,the common emitter current gain is calcula...Based on the material characteristics and the operational principle of the double base epilayer BJTs,and according to the drift-diffusion and the carrier recombination theory,the common emitter current gain is calculated considering four recombination processes.Then its performance is analyzed under high temperature conditions.The results show that the emitter injection efficiency decreases due to an increase in the base ionization rate with increasing temperature.Meanwhile,the SiC/SiO2 interface states and the quality of the passivation layer will affect the surface recombination velocity,and make an obvious current gain fall-off at a high collector current.展开更多
随着工艺制程的不断微缩,动态随机存储器(dynamic random access memory,DRAM)的集成度持续提高,单颗芯片上存储单元的数目呈指数增长,随之带来的是芯片发热严重和泄漏电流增大等问题,为了实时监测内部温度并控制相应的刷新操作,DRAM需...随着工艺制程的不断微缩,动态随机存储器(dynamic random access memory,DRAM)的集成度持续提高,单颗芯片上存储单元的数目呈指数增长,随之带来的是芯片发热严重和泄漏电流增大等问题,为了实时监测内部温度并控制相应的刷新操作,DRAM需要在内部集成温度传感器。文章从DRAM的基本结构、工作原理和实际工作中对内置温度传感器的需求出发,研究不同读出架构的集成式温度传感器的优缺点,考虑到感温精度、感温范围、功耗和成本等因素以及DRAM产品规格说明书中对内置温度传感器的要求,设计出一款基于时域读出架构的免校准低功耗温度传感器。采用19 nm的互补金属氧化物半导体(complementary metal oxide semiconductor,CMOS)工艺进行仿真验证,结果表明,免校准的前提下,该温度传感器在0~110℃的感温范围内具有3℃的仿真精度,版图面积为0.189 mm^(2),平均功耗为340.31μW,感温时间为550μs。文章设计的温度传感器满足DRAM对于内置温度传感器的要求,且大大降低了DRAM的生产成本。展开更多
基金Project supported by the National Natural Science Foundation of China(No.60876061)the Pre-Research Project of China(No. 51308040302).
文摘According to the avalanche ionization theory,a computer-based analysis is performed to analyze the structural parameters of single-and multiple-zone junction termination extension（JTE） structures for 4H-SiC bipolar junction transistors（BJTs） with mesa structure.The calculation results show that a single-zone JTE can yield high breakdown voltages if the activated JTE dose and the implantation width are controlled precisely and a multiple-zone JTE method can decrease the peak surface field while still maintaining a high blocking capability.The influences of the positive and negative surface or interface states on the blocking capability are also shown.These conclusions have a realistic meaning in optimizing the design of a mesa power device.
基金Project supported by the National Natural Science Foundation of China(No.60876061)the Key Laboratory Foundation of China (No.20090C1403)
文摘Based on the material characteristics and the operational principle of the double base epilayer BJTs,and according to the drift-diffusion and the carrier recombination theory,the common emitter current gain is calculated considering four recombination processes.Then its performance is analyzed under high temperature conditions.The results show that the emitter injection efficiency decreases due to an increase in the base ionization rate with increasing temperature.Meanwhile,the SiC/SiO2 interface states and the quality of the passivation layer will affect the surface recombination velocity,and make an obvious current gain fall-off at a high collector current.
文摘随着工艺制程的不断微缩,动态随机存储器(dynamic random access memory,DRAM)的集成度持续提高,单颗芯片上存储单元的数目呈指数增长,随之带来的是芯片发热严重和泄漏电流增大等问题,为了实时监测内部温度并控制相应的刷新操作,DRAM需要在内部集成温度传感器。文章从DRAM的基本结构、工作原理和实际工作中对内置温度传感器的需求出发,研究不同读出架构的集成式温度传感器的优缺点,考虑到感温精度、感温范围、功耗和成本等因素以及DRAM产品规格说明书中对内置温度传感器的要求,设计出一款基于时域读出架构的免校准低功耗温度传感器。采用19 nm的互补金属氧化物半导体(complementary metal oxide semiconductor,CMOS)工艺进行仿真验证,结果表明,免校准的前提下,该温度传感器在0~110℃的感温范围内具有3℃的仿真精度,版图面积为0.189 mm^(2),平均功耗为340.31μW,感温时间为550μs。文章设计的温度传感器满足DRAM对于内置温度传感器的要求,且大大降低了DRAM的生产成本。
