具有高频高压大电流优值的超结集电区SiGe HBT

为了在兼顾特征频率( fT )和电流增益(β)的情况下有效提高器件的击穿电压( BVCBO/BVCEO ),利用SILVACO TCAD建立了npn型超结集电区SiGe异质结双极晶体管( heterojunction bipolar transistor,HBT)的器件模型.研究表明：通过在集电结空间电荷区( collector-base space charge region,CB SCR)内引入p型超结层可有效降低“死区”内的电场强度,使较高的电场强度转移至“死区”外较深的CB SCR内,进而在几乎不增加CB SCR宽度的情况下抑制碰撞电离,达到提高击穿电压、改善fT和β的目的.随着p型超结层厚度( dp )的增加,击穿电压BVCBO和BVCEO的改善也越明显.但dp值需优化,较大的dp值将引发Kirk效应,大幅降低器件的fT和β.进一步通过优化p型超结层的dp值,设计出一款dp为0.2μm且具有高频高压大电流优值( fT ×BVCEO ×β)的新型超结集电区SiGe HBT.结果表明：与传统SiGe HBT相比,新器件的fT ×BVCEO ×β优值改善高达35.5%,有效拓展了功率SiGe HBT的高压大电流工作范围.     

Above 700 V superjunction MOSFETs fabricated by deep trench etching and epitaxial growth

Silicon superjunction power MOSFETs were fabricated with deep trench etching and epitaxial growth,based on the process platform of the Shanghai Hua Hong NEC Electronics Company Limited.The breakdown voltages of the fabricated superjunction MOSFETs are above 700 V and agree with the simulation.The dynamic characteristics,especially reverse diode characteristics,are equivalent or even superior to foreign counterparts.     

A superjunction structure using high-k insulator for power devices: theory and optimization

A superjunction (SJ) structure using a high-k (Hk) insulator is studied and optimized by using an analytic model. Results by using the proposed model match well with that of numerical calculations. Numerical calculation results show that, only needing an Hk insulator with a permittivity of ε_I=5ε_S, the optimum specific on-resistance of the MOSFET applying the proposed structure is about 8%-20% lower than that of the conventional SJ-MOSFET with V_B=200-1000 V. An example with V_B=400 V shows that, the permissible error range of doping concentration of the p-region to maintain above 80% of V_B is from -37% to +32% for the former and is only from -13% to +13% for the latter.     

超结MOSFET功率器件的终端技术分析

为了改善超结MOSFET功率器件的终端击穿特性,提出了一种平面结终端技术,应用柱坐标下的泊松方程证明了这种技术的可行性。提出了超结功率器件终端技术的工艺实现方法并分析了终端结构的电压特性,使用这种超结终端技术仿真得到了一个600V的Coolmos。利用2维仿真软件Medici讨论了终端p柱的数量和宽度因素对击穿电压和表面电场的影响。结果发现,采用变间距的超结结构本身就可以很好地实现超结MOSFET功率器件的终端。     

采用深槽刻蚀和外延生长技术的700V超结MOSFETs

超结理论的提出是功率器件领域发展的重要里程碑。基于HHNEC的工艺平台,采用深槽刻蚀和外延生长技术,得到了击穿电压大于700V的超结功率MOSFETs,实验值和仿真值吻合好。结果表明,所研制的超结功率MOSFETs,动态特性,特别是二极管的特性,优于国外同类型产品。该种结构的实验成功,打破了国内在该领域实用化研究的空白。     

A review of manufacturing technologies for silicon carbide superjunction devices

Superjunction technology is believed to reach the optimal specific on-resistance and breakdown voltage trade-off.It has become a mainstream technology in silicon high-voltage metal oxide semiconductor field effect transistor devices.Numer-ous efforts have been conducted to employ the same concept in silicon carbide devices.These works are summarized here.     

Trench SJ IGBT 的仿真研究

本文对沟槽型超结绝缘栅双极晶体管(trench SJ IGBT)进行了全面的分析,并通过Sentaurus TCAD仿真软件将其与沟槽型场截止绝缘栅双极晶体管(trench FS IGBT)进行了详尽的对比,仿真结果显示,在相同的条件下与trench FS IGBT 相比,trench SJ IGBT 的击穿电压提高了100 V,饱和导通压降降低了0.2 V,关断损耗减少了50%。最后,文章研究了电荷不平衡对trench SJ IGBT 的动静态参数的影响。对各参数和它们对电荷不平衡的灵敏度之间的折中进行了讨论。     

六角形超结VDMOS器件的终端结构设计

为六角形超结VDMOS器件提出了一种结终端结构,该终端结构采用与有源区相似的六角形晶格结构,但P柱和N柱的宽度均为有源区原胞晶格的一半.重点讨论了P柱的数量对表面电场的分布及击穿电压等的影响,模拟结果证实该终端结构的击穿电压大于600 V,击穿点发生在终端与有源区之间的过渡区.     

An optically controlled SiC lateral power transistor based on SiC/SiCGe superjunction structure

An optically controlled SiC/SiCGe lateral power transistor based on superjunction structure has been proposed, in which n-SiCGe/p-SiC superjunction structure is employed to improve device figure of merit. Performance of the novel optically controlled power transistor was simulated using Silvaco Atlas tools, which has shown that the device has a very good response to the visible light and the near infrared light. The optoelectronic responsivities of the device at 0.5 μm and 0.7 μm are 330 mA/W and 76.2 mA/W at 2 V based voltage, respectively.     

An optically controlled SiC lateral power transistor based on SiC/SiCGe superjunction structure

An optically controlled SiC/SiCGe lateral power transistor based on superjunction structure has been proposed, in which n-SiCGe/p-SiC superjunction structure is employed to improve device figure of merit. Performance of the novel optically controlled power transistor was simulated using Silvaco Atlas tools, which has shown that the device has a very good response to the visible light and the near infrared light. The optoelectronic responsivities of the device at 0.5 μm and 0.7 μm are 330 mA/W and 76.2 mA/W at 2 V based voltage, respectively.