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提出一种超结硅锗碳异质结双极晶体管(SiGeC HBT)新结构.详细分析了新结构中SiGeC基区和超结结构的引入对器件性能的影响,并对其电流输运机制进行研究.基于SiGeC/Si异质结技术,新结构器件的高频特性优良;同时超结结构的存在,在集电区内部水平方向和垂直方向都建立了电场,二维方向上的电场分布相互作用大大提高了新结构器件的耐压能力.结果表明:超结SiGeC HBT与普通结构SiGeC HBT相比,击穿电压提高了48.8%;更重要的是SiGeC HBT器件中超结结构的引入,不会改变器件高电流增益、高频率特性的优点;新结构器件与相同结构参数的Si双极晶体管相比,电流增益提高了10.7倍,截止频率和最高震荡频率也得到了大幅度改善,很好地实现了高电流增益、高频率特性和高击穿电压三者之间的折中.对超结区域的柱区层数和宽度进行优化设计,随着柱区层数的增多,击穿电压显著增大,电流增益有所提高,截止频率和最高震荡频率减低,但幅度很小.综合考虑认为超结区域采用pnpn四层结构是合理的.
A new structure of SiGeC HBT (SiGeC HBT) is proposed.The influences of the introduction of SiGeC base region and the super-junction structure on the device performance are analyzed in detail, and the current transport mechanism Based on the SiGeC / Si heterojunction technology, the high-frequency characteristics of the new device are excellent. At the same time, the existence of the super-junction structure establishes an electric field both horizontally and vertically in the collector region. The electric field distribution in the two- The results show that the breakdown voltage of superconjugated SiGeC HBT is improved by 48.8% compared with that of SiGeC HBT. More importantly, the introduction of super-junction structure in SiGeC HBT devices does not Changing the high-current gain and high-frequency characteristics of the device. Compared with Si bipolar transistors with the same structural parameters, the new structure device has a current gain of 10.7 times higher, and the cut-off frequency and the maximum oscillation frequency have also been greatly improved. The high current gain, high frequency characteristic and high breakdown voltage are compromised between the three. The number and width of the pillars in the super-junction region are optimized. With the increase of the number of pillars, the breakdown voltage is significant increase , Improved current gain cut-off frequency and maximum oscillation frequency reduction, but only slightly. Considering think super-junction region using pnpn four-layer structure is reasonable.