CAJ | 학술논문

通过商用半导体模拟器MEDICI对700 V 4H-SiC晶闸管开通特性进行了模拟研究.模拟结果表明阳极电压小于100 V时,开通过程符合扩散模型,电压更高时,开通时间随阳极电压升高而迅速下降,符合场开通机制.不同于Si及GaAs晶闸管,SiC晶闸管p型耐压层中浅能级杂质Al使得其开通时间随温度的升高而降低.较厚的基区使得电导调制效应只发生在发射区与基区边界一个范围之内,随着温度的升高,其余部分的载流子数目指数增加,压降指数减小.开通时间随着门极触发电流的加大而逐渐缩短,减小到一定程度时,减小速度明显变缓.
통과상용반도체모의기MEDICI대700 V 4H-SiC정갑관개통특성진행료모의연구.모의결과표명양겁전압소우100 V시,개통과정부합확산모형,전압경고시,개통시간수양겁전압승고이신속하강,부합장개통궤제.불동우Si급GaAs정갑관,SiC정갑관p형내압층중천능급잡질Al사득기개통시간수온도적승고이강저.교후적기구사득전도조제효응지발생재발사구여기구변계일개범위지내,수착온도적승고,기여부분적재류자수목지수증가,압강지수감소.개통시간수착문겁촉발전류적가대이축점축단,감소도일정정도시,감소속도명현변완.
The steady-state current-voltage characteristics and turn-on process of 700 V 4HSiC thyristors were simulated with commercial simulator MEDICI.The simulation results indicate the turn-on process is consistent with diffusion model at low voltage (＜100 V),but the turn-on time decreases with the increase of voltage (＞100 V),which obeys the field mechanism of the turn-on process.Different from Si and GaAs thyristors,the dopant aluminum served as shallow energy impurity in p-type SiC voltage sustaining layer,makes turn-on time be decreased with temperature.The relatively thick base region enables the conductivity modulation effect only to be active in a region far from the emitter.Meanwhile,the carrier concentration increases exponentially (voltage decreases exponentially) in other regions when the temperature is enhanced.It is also found that the turn-on time is a strong function of the gate current and decreases with increasing of the current.